Source: https://pubs.rsc.org/en/content/articlehtml/2019/sc/c8sc04271c
Timestamp: 2019-04-23 00:04:26+00:00

Document:
This perspective report presents the key approaches for the development of various organometallic reactions in aqueous media. In view of future sustainability, the efficient use of natural resources, such as renewable biomass-based feedstocks, constitutes an important aspect for sustainable chemical industry. The exploration and discovery of efficient organometallic reactions or equivalents in water enrich the toolbox of organic chemists for the direct conversion of biomass-derived feedstocks into high-valued chemicals and the direct modification of biomolecules in their native aqueous environment, which contributes to future sustainability.
Carbon–carbon bond formation plays the central role in synthetic organic chemistry. For polar routes, such transformations necessarily involve carbon nucleophiles and electrophiles.1 One class of the most commonly used nucleophiles is organometallic compounds. Since the discovery of alkylzinc compounds by Frankland from the reaction of iodoalkanes with metallic zinc,2 organometallic reagents serving as nucleophiles for organic syntheses have been rapidly evolved both in scope and application.3–7 The early discoveries of Reformatsky,8 Barbier,9 Grignard,10 and Gilman11 are among the important milestones in the development of classical organometallic reactions. Subsequently, there have been great progresses in the use of alkali12 and other metals since the 1930s. Recently, organometallic reactions catalysed by transition metals have become increasingly important in the synthesis of organic molecules,13 underscored by three Nobel Prizes: for palladium-catalysed cross-coupling in 2010,14–16 olefin metathesis in 2005 17–19 and asymmetric catalysis in 2001 20–22 within the last decade.
Most classical organometallic compounds are highly polarized as carbanions, which are also strong bases. Consequently, they are unstable towards active protons (moisture or functional groups) and must be synthesized/used under strictly anhydrous/aprotic conditions. Conceptually, the key to developing successful organometallic reactions in water (aqueous media) is to attenuate or prevent the protonation of carbon–metal bond once the organometallic species is generated (eqn (1)).
There are several conceivable approaches to achieve this objective. The most straightforward approach is to tune the relative electronegativity33 between carbon and metal atoms to form the more covalent C–M bond. A second approach is to design radical pathways, as the strong O–H bond (enthalpy 436 kJ mol−1) is very difficult to break homolytically. The third approach is to mimic nature's lipid bilayer membrane34 by physically segregating and temporarily stabilizing the organometallic species from water via micelle formation using surfactants35 or on water strategy.36–38 The fourth approach is to bypass the stoichiometric organometallic reagents by transition-metal-catalysed organic transformations in water, such as via C–H bond activation and hydrazone umpolung.39,40 This perspective article will illustrate these aspects using the classical nucleophilic additions as examples.
The main reason for the necessary anhydrous conditions in classical organometallic reactions was due to the highly polarized and reactive C–M bonds towards water,3 especially the organometallic compounds of s-block elements. As C–M bonds become more covalent, such as the organometallic compounds of group 14 and group 15, they have less carbanion character and thus are less prone to acidic proton and relatively more stable in aqueous media. Different from s-block and late p-block organometallic compounds, the ones from group 13 elements take up a special position within the main group due to their moderate reactivity towards water.41 Furthermore, certain classes of organometallics remain viable in the presence of water. For example, the preparation of arylmercuric chlorides in aqueous media has been known since 1905.42 In the 1960's, tribenzylstannyl halide was prepared in large scale in water (Scheme 1).43–45 The Wurtz-type reductive coupling of allyl halides proceeded in aqueous alcohol.46 These reports opened up new perspectives regarding the metal-mediated organic reactions and it has been increasingly realized that these kinds of reactions can be conducted in water under special circumstances. Indeed, there has been great progress in this research area over the past decades, such as allylation,47–49 allenylation,50,51 propargylation,52,53 benzylation,54 phenylation55,56etc.
Scheme 1 Direct synthesis of tribenzylstannyl halide in water.
The most explored reaction is the allylation of carbonyls and other electrophiles with allyl halides mediated by various metals (Scheme 2),57 among which the use of indium to mediate the Barbier–Grignard-type reactions in water reported by Li and Chan received particular attention (Scheme 3).48 This was attributed to the fact that on one hand, indium possesses the lowest first ionization potential among the metallic elements near it in the periodic table; and on the other hand, it does not form oxides readily in air and is not sensitive to boiling water or alkali. Consequently, indium was shown to be the most effective for such transformations in water, proceeding smoothly at room temperature without any promoter. This methodology has found wide applications in aqueous synthetic chemistry,58–61 particularly important in carbohydrate chemistry.
Scheme 2 Allylation of carbonyl and imine compounds.
Scheme 3 Indium-mediated carbonyl allylation in aqueous media.
Scheme 4 Synthesis of (+)KDN.
Scheme 5 Synthesis of (+)KDO.
Scheme 6 Synthesis of (+)-N-acetyl neuraminic acid.
Scheme 7 In-mediated carbocyclic ring expansion in water.
Scheme 8 In-mediated diastereoselective allylation of α-oxy aldehydes in water.
In 2002, Delgado and co-workers reported a Barbier-type diastereoselective allylation of α-amino aldehydes with an enantiopure 2-sulfinylallyl building block in aqueous media mediated by zinc (Scheme 9).79 High levels of diastereoinduction can be achieved from α-amino aldehydes configurationally related to natural α-amino acids.
Scheme 9 Zinc-mediated Barbier-type diastereoselective allylation of α-amino aldehydes with 2-sulfinylallyl chloride in aqueous media.
Scheme 10 (a) In-mediated enantioselective allylation of aldehydes using chiral pyridine bis(oxazoline) ligand; (b) AgNO3/(S)-Tol-BINAP-catalysed enantioselective allyation of aldehydes using allyltributylstannane in an aqueous media; (c) In(III)–(S)-BINOL complex catalysed enantioselective allylation of aldehyde using allyltributylstannane in an aqueous media.
In 2003, Kobayashi and co-workers reported a catalytic asymmetric allylation of aldehydes using allyltributyltin in aqueous media via the combination of cadmium bromide and chiral diamine ligands. Interestingly, these ligands were found to accelerate the reactions significantly (Scheme 11).83 Later, they reported an In-catalysed allylation of ketone with allyl boronates in water (Scheme 12).84 Preliminary asymmetric study using chiral bis-oxazoline ligand showed that a moderate enantioselectivity can be obtained.
Scheme 11 Cd-catalysed asymmetric allylation of aldehyde using allyltributylstannane in an aqueous media.
Scheme 12 In-catalysed asymmetric allylation of ketone using allyl boronate in water.
Scheme 13 In-mediated propargylation of aldehydes in water.
Scheme 14 In-mediated propargylation of imines.
Scheme 15 Indium-mediated allenylation in aqueous media and its application to the synthesis of (+)-goniofufurone.
Scheme 16 Zn-mediated benzylation of carbonyl compounds in aqueous media in the presence of CdCl2 and InCl3.
Scheme 17 (a) Rh-catalysed carbonyl phenylation in water; (b) the electronic effect on Rh-catalysed carbonyl additions with arylmetallic reagents.
Radicals are neutral species with one unpaired valence electron, which, in contrast to organic anions and cations, make them chemically “stable” towards water. Indeed, the aqueous radical chemistry predominates in biological processes.102,103 As radicals are nonpolar, their additions to C C bonds were first realized in water. In 1998, Oshima and co-workers reported that the Et3B-induced atom transfer radical cyclization of allyl iodoacetate proceeded much more smoothly in water at ambient temperature than in benzene or hexane (Scheme 18a).104 Treatment of the allylic iodoacetate in water with Et3B (metalloid) at room temperature for 3 h provided β-iodomethyl-γ-butyrolactone in 67% yield. In contrast, in benzene the desired product was not obtained at all and oligomeric by-products were formed.
Scheme 18 Et3B-induced atom transfer radical cyclization in water.
The remarkable solvent effect of water was also observed in the case of medium and large ring construction. For example, Oshima and co-workers reported an intramolecular cyclization mediated by Et3B in water provided the 9-membered lactone in 69% yield (Scheme 18b). The same reaction carried out in benzene afforded much inferior yield.105 Although the exact role of water was not clear at that stage, a hydrogen bonding between water and the carbonyl oxygen could be formed to facilitate the abstraction of iodine, generating the (alkoxycarbonyl)methyl radical. Hydrophobic interaction may also accelerate the cyclization.
Scheme 19 Zinc–copper couple-mediated conjugate additions of alkyl halides to carbonyl compounds in aqueous media and the proposed radical mechanism.
Scheme 20 Zinc–copper couple-mediated conjugate addition of alkyl halides to vinylphosphine oxides in aqueous media.
Giese and co-workers studied the diastereoselectivity associated with a related addition in water113 and found that the anti-isomer was the main product if the attacking radical is bulky (Scheme 21).
Scheme 21 Zinc–copper couple-mediated conjugate addition of alkyl halides and electron-deficient alkenes in water.
The authors rationalized the high diastereoselectivity by proposing that the more stable ‘A-strain’ conformer of the alkene reacts much slower with bulky alkyl radical than the less stable ‘Felkin–Anh’ conformer.
Scheme 22 Zinc–copper couple-mediated diastereoselective addition of alkyl iodides and α,β-unsaturated compounds in water.
Scheme 23 Zinc-mediated conjugate addition of alkyl halides to α-phthalimidoacylate and imine derivatives in aqueous media.
Scheme 24 Barbier–Grignard allylation of aldehydes with magnesium in water.
In 2002, Naito and co-workers reported an intermolecular alkyl radical addition to imine derivatives and electron-deficient C–C double bond in aqueous media by using indium as a single-electron-transfer radical initiator (Scheme 25).118 The one-pot reaction provided a convenient method for preparing α-amino acids.
Scheme 25 In-mediated alkyl radical addition to imine and phenyl vinyl sulfone derivatives in aqueous media.
In 2003, they reported an indium-mediated cascade reaction, in which the addition–cyclization–trapping sequences efficiently generated the cyclized products in aqueous media (Scheme 26).119 The substrates bearing vinylsulfonamide and hydrazone proceeded smoothly in aqueous media to provide the functionalized cyclic products.
Scheme 26 Indium-mediated radical addition–cyclization–trapping cascade reaction in aqueous media.
Scheme 27 Zinc-mediated Barbier–Grignard-type carbonyl alkylation in water.
In 2008, Loh and co-workers further developed this Barbier–Grignard-type alkylation reaction of aldehydes including aliphatic version using unactivated alkyl halides in water catalysed by In/CuI or In/AgI catalysis (Scheme 28).121 The reactions proceeded more efficiently in water than in organic solvent.
Scheme 28 In/CuI or In/AgI-mediated alkylation of carbonyls in water.
Scheme 29 Zn, Sn and In-mediated direct cross-aldol reactions of aldehydes and α-halogen carbonyls.
Scheme 30 Zinc-mediated Reformatsky-type reaction of bromoacetates and aromatic aldehydes and the proposed radical chain mechanism.
Scheme 31 In-mediated synthesis of α,α-difluoro-β-hydroxy ketones in water.
Scheme 32 Zinc-mediated asymmetric Mannich-type reactions in water using CTAB as surfactant.
Scheme 33 Cu-catalysed and zinc-mediated conjugate additions of alkyl halides to enones in aqueous media using TPGS-750-M as surfactant.
Scheme 34 Rh-catalysed and Zn-mediated Barbier–Grignard-type arylation of aldehydes in water using BrijC10 as surfactant.
In 2018, Lipshutz and co-workers developed an environmentally responsible, mild method for the synthesis of functionalized 1,3-butadienes via Pd-catalyzed cross-coupling of substituted allenic esters in water in the presence of the surfactant TPGS-750-M (Scheme 35).135 Various sp–sp2, sp2–sp2, and sp2–sp3 coupling reactions were realized and these transformations tolerated broad functional groups.
Scheme 35 Pd-catalysed cross-coupling of substituted allenic esters for the synthesis of functionalized 1,3-butadienes in water in the presence of the surfactant TPGS-750-M.
Scheme 36 (a) Formation of THF derivatives via nucleophilic additions of Grignard reagents to γ-chloroketone using on water strategy; (b) on-water addition of organolithium and organomagnesium reagents to imines and nitriles.
Scheme 37 Ru/In co-catalysed alkynylation of aldehydes in water.
Scheme 38 Cu/pyridine-oxazoline catalysed asymmetric addition of phenylacetylene to imine in water via C(sp)–H activation.
For the less acidic C(sp2)–H bonds, one strategy to facilitate their reaction in water is via chelation. In 2010, Dixneuf and co-workers reported a Ru-catalysed and pyridine-directed C(sp2)–H bond activation in water for efficient ortho-phenylation (Scheme 39).150 The selectivity of mono-phenylation and bis-phenylations was found to be better in water than in organic solvent.
Scheme 39 Ru-catalysed ortho-phenylation in water via C(sp2)–H bond activation.
Scheme 40 Ru-catalysed tandem cyclization of aniline derivative and alkyne for indole synthesis in water via C(sp2)–H bond activation.
Scheme 41 Rh-catalysed 2-phenylation of indole derivatives in water via C(sp2)–H bond activation.
Scheme 42 Rh-catalysed homo-coupling of aryl carboxylic acid in water via two-fold C(sp2)–H bond activation.
Such a chelation strategy can also be applied towards the least acidic C(sp3)–H bonds. For example, in 2014, Chen and co-workers reported a Pd-catalysed N-quinolylcarboxamide directed β-arylation of alanine at room temperature via C(sp3)–H bond activation, in which water is used as a co-solvent (Scheme 43).154 This method provided a convenient approach for the synthesis of both natural and unnatural aromatic α-amino acids.
Scheme 43 Pd-catalysed N-quinolylcarboxamide directed β-arylation of alanine at room temperature via C(sp3)–H bond activation using water as a co-solvent.
In 2015, Rao and coworkers reported the Pd-catalysed β-C(sp3)–H bond oxidation of amides using 8-aminoquinoline as directing group in water (Scheme 44).155 Interestingly, the isotope labelling experiment indicates that the oxygen originates from water.
Scheme 44 Pd-catalysed β-C(sp3)–H bond oxidation of amides using 8-aminoquinoline as directing group in water.
Scheme 45 The peroxide-mediated direct addition of cycloalkanes to imines.
Via hydrazone umpolung. Umpolung is a phenomenon in which the polarity of a functional group is reversed.157,158 This opens up reactions on a functional group which is otherwise not possible. In nature, numerous enzymes such as acetohydroxy acid pseudoephedrine synthase (AHAS) catalyse both nucleophilic acylation and benzoin condensation reactions in aqueous media via umpolung strategy, in which a cofactor thiamine pyrophosphate (TPP) facilitates the catalytic function of these enzymes (Scheme 46).159–161 Inspired by the biocatalytic methods that use enzymes as catalysts for various C–C bond forming reactions, chemists have successfully developed numerous C–C forming reactions based on umpolung with carbonyls as acyl anion equivalents. Most of those reactions were catalysed by either N-heterocyclic carbene (NHC) or cyanide ion.162,163 Related to organometallic reactions, one attractive approach is the metal-catalysed umpolung chemistry via hydrazone intermediate that originates from naturally occurring carbonyls (Scheme 47). This strategy not only improves compatibility towards benign protic solvents and accommodates various functional groups, but also provides an opportunity for enantioselective catalysis when involving chiral ligands.
Scheme 46 AHAS catalysed acyloin condensation and the synthesis of ephedrine.
Scheme 47 Metal-catalysed umpolung chemistry via hydrazone intermediate.
In 2017, Li and co-workers reported the ruthenium catalysed umpolung strategy for the nucleophilic addition to carbonyl164 (Scheme 48a) and aryl imine165 (Scheme 48b) compounds through hydrazone intermediates using aldehydes as carbanion equivalents. The unique chemoselectivity exhibited by carbonyl-derived carbanion equivalents is demonstrated by their tolerance to protic reaction media and good functional group compatibility.
Scheme 48 Ru-catalysed nucleophilic addition of carbonyl and aryl imine compounds via hydrazone intermediate using aldehydes as carbanion equivalents.
Scheme 49 Ruthenium-catalysed conjugate additions via hydrazone intermediate.
Recently, Li and coworkers reported a nickel-catalysed C(sp2)–C(sp3) cross-coupling reaction from two sustainable biomass-based feedstocks: phenol derivatives with umpolung aldehydes through moisture/air-stable hydrazones intermediate generated in situ (Scheme 50).167 Water tolerance, functional group compatibility and late-stage elaboration of complex biological molecules exemplified its practicability and unique chemoselectivity over stoichiometric organometallic reagents. Further development of such reactions in water is foreseen and being actively pursued in our lab.
Scheme 50 Nickel-catalysed C(sp2)–C(sp3) cross-coupling reaction via hydrazone intermediate.
The past few decades have witnessed the rapid development of water-based organic synthesis, in which the organometallic reactions in water has also made considerable progress. This article aims to summarize the key approaches for realizing the various organometallic reactions focusing on nucleophilic additions in aqueous media, which provides the readers with perspectives for further developments in this field. In view of future sustainability, the use of renewable biomass-based feedstocks constitutes an important part for sustainable development of chemical industry. The development of efficient organometallic reactions in water provides important tools for the direct conversion of biomass-derived feedstocks into high-valued chemicals and direct modification of biomolecules under native aqueous environment, and constitutes overall synthetic efficiency.
We are grateful to the Canada Research Chair Foundation (to C.-J. L.), the Canadian Foundation for Innovation, FRQNT Centre in Green Chemistry and Catalysis, and the Natural Science and Engineering Research Council of Canada for support of our researches.
R. V. Hoffman, in Organic Chemistry: An Intermediate Text, John Wiley & Sons, Inc., 2nd edn, 2004, ch. 8 Search PubMed.
E. von Frankland, Liebigs Ann., 1849, 71, 171–213 CrossRef.
E. W. Abel, F. G. A. Stone and G. Wilkinson, Comprehensive Organometallic Chemistry II: A Review of the Literature 1982–1994, Pergamon, Oxford; New York, 1995 Search PubMed.
D. M. P. Mingos and R. H. Crabtree, Comprehensive Organometallic Chemistry III, Elsevier, Amsterdam, Boston, 2007 Search PubMed.
P. Knochel and I. Wiley, Handbook of Functionalized Organometallics: Applications in Synthesis, Wiley-VCH, Weinheim, 2005 Search PubMed.
D. H. B. Ripin, in Practical Synthetic Organic Chemistry, ed. S. Caron, 2011, ch. 12 Search PubMed.
R. Chinchilla, C. Nájera and M. Yus, Chem. Rev., 2004, 104, 2667–2722 CrossRef CAS PubMed.
S. Reformatsky, Ber. Dtsch. Chem. Ges., 1887, 20, 1210–1211 CrossRef.
P. Barbier, C. R. Acad. Sci., 1899, 128, 110 CAS.
V. Grignard, C. R. Acad. Sci., 1900, 130, 1322 CAS.
H. Gilman, R. G. Jones and L. A. Woods, J. Org. Chem., 1952, 17, 1630–1634 CrossRef CAS.
M. J. Harvey, in Alkali Metals: Organometallic Chemistry, Encyclopedia of Inorganic and Bioinorganic Chemistry, 2014 Search PubMed.
B. C. G. Söderberg, Coord. Chem. Rev., 2008, 252, 57–133 CrossRef.
R. F. Heck, Acc. Chem. Res., 1979, 12, 146–151 CrossRef CAS.
E.-I. Negishi, Angew. Chem., Int. Ed., 2011, 50, 6738–6764 CrossRef CAS PubMed.
A. Suzuki, Angew. Chem., Int. Ed., 2011, 50, 6722–6737 CrossRef CAS PubMed.
R. H. Grubbs, Angew. Chem., Int. Ed., 2006, 45, 3760–3765 CrossRef CAS PubMed.
R. R. Schrock, Angew. Chem., Int. Ed., 2006, 45, 3748–3759 CrossRef CAS PubMed.
Y. Chauvin, Angew. Chem., Int. Ed., 2006, 45, 3740–3747 CrossRef PubMed.
W. S. Knowles, Adv. Synth. Catal., 2003, 345, 3–13 CrossRef CAS.
N. Ryoji, Angew. Chem., Int. Ed., 2002, 41, 2008–2022 CrossRef.
K. B. Sharpless, Angew. Chem., Int. Ed., 2002, 41, 2024–2032 CrossRef CAS PubMed.
W. Keim, Fossil Feedstocks–What Comes After?, Springer-Verlag, Berlin Heidelberg, 2014 Search PubMed.
M. Z. Jacobson, Air Pollution and Global Warming: History, Science, and Solutions, Cambridge University Press, 2nd edn, 2012 Search PubMed.
M. Z. Jacobson, Energy Environ. Sci., 2009, 2, 148–173 RSC.
F. Cherubini, Energy Convers. Manage., 2010, 51, 1412–1421 CrossRef CAS.
C.-J. Li, Green Chem., 2016, 18, 1836–1838 RSC.
B. M. Trost, Science, 1991, 254, 1471–1477 CrossRef CAS PubMed.
R. A. Sheldon, Chem. Tech., 1994, 24, 38–47 CAS.
P. A. Wender, V. A. Verma, T. J. Paxton and T. H. Pillow, Acc. Chem. Res., 2008, 41, 40–49 CrossRef CAS PubMed.
A. L. Allred, J. Inorg. Nucl. Chem., 1961, 17, 215–221 CrossRef CAS.
G. van Meer, D. R. Voelker and G. W. Feigenson, Nat. Rev. Mol. Cell Biol., 2008, 9, 112 CrossRef CAS PubMed.
X. Cui, S. Mao, M. Liu, H. Yuan and Y. Du, Langmuir, 2008, 24, 10771–10775 CrossRef CAS PubMed.
A. Chanda and V. V. Fokin, Chem. Rev., 2009, 109, 725–748 CrossRef CAS PubMed.
R. N. Butler and A. G. Coyne, Org. Biomol. Chem., 2016, 14, 9945–9960 RSC.
Y. Jung and R. A. Marcus, J. Am. Chem. Soc., 2007, 129, 5492–5502 CrossRef CAS PubMed.
C.-J. Li and T. H. Chan, Organic Reactions in Aqueous Media, John Wiely & Sons, New York, 1997 Search PubMed.
C.-J. Li, Chem. Rev., 2005, 105, 3095–3166 CrossRef CAS PubMed.
F. A. Cotton and G. Wilkinson, Advanced Inorganic Chemistry: A Comprehensive Text, Wiley, New York, 1980 Search PubMed.
W. Peters, Ber. Dtsch. Chem. Ges., 1905, 38, 2567 CrossRef CAS.
K. Sisido, Y. Takeda and Z. Kinugawa, J. Am. Chem. Soc., 1961, 83, 538–541 CrossRef.
K. Sisido, S. Kozima and T. Hanada, J. Organomet. Chem., 1967, 9, 99–107 CrossRef CAS.
K. Sisido and S. Kozima, J. Organomet. Chem., 1968, 11, 503–513 CrossRef CAS.
J. Nosek, Collect. Czech. Chem. Commun., 1964, 29, 597–602 CrossRef CAS.
J. Nokami, J. Otera, T. Sudo and R. Okawara, Organometallics, 1983, 2, 191–193 CrossRef CAS.
C.-J. Li and T. H. Chan, Tetrahedron Lett., 1991, 32, 7017–7020 CrossRef CAS.
T.-P. Loh, Q.-Y. Hu, Y.-K. Chok and K.-T. Tan, Tetrahedron Lett., 2001, 42, 9277–9280 CrossRef CAS.
X.-H. Yi, Y. Meng and C.-J. Li, Chem. Commun., 1998, 449–450 RSC.
X.-H. Yi, Y. Meng, X.-G. Hua and C.-J. Li, J. Org. Chem., 1998, 63, 7472–7480 CrossRef CAS PubMed.
M. B. Isaac and T.-H. Chan, J. Chem. Soc., Chem. Commun., 1995, 1003–1004 RSC.
T. M. Mitzel, C. Palomo and K. Jendza, J. Org. Chem., 2001, 67, 136–145 CrossRef.
L. W. Bieber, E. C. Storch, I. Malvestiti and M. F. da Silva, Tetrahedron Lett., 1998, 39, 9393–9396 CrossRef CAS.
C.-J. Li and Y. Meng, J. Am. Chem. Soc., 2000, 122, 9538–9539 CrossRef CAS.
T. Huang, Y. Meng, S. Venkatraman, D. Wang and C.-J. Li, J. Am. Chem. Soc., 2001, 123, 7451–7452 CrossRef CAS PubMed.
C.-J. Li, Tetrahedron, 1996, 52, 5643–5668 CrossRef CAS.
L. Rodolfo, C. Oscar, B. Joan, O. Modesto and L. F. Javier, Eur. J. Org. Chem., 2001, 3719–3729 Search PubMed.
D. Backhaus, Tetrahedron Lett., 2000, 41, 2087–2090 CrossRef CAS.
J. S. Yadav and C. Srinivas, Tetrahedron Lett., 2002, 43, 3837–3839 CrossRef CAS.
A. Jeevanandam and Y.-C. Ling, Tetrahedron Lett., 2001, 42, 4361–4362 CrossRef CAS.
T. H. Chan and C.-J. Li, J. Chem. Soc., Chem. Commun., 1992, 747–748 RSC.
A. Dondoni, P. Merino and J. Orduna, Tetrahedron Lett., 1991, 32, 3247–3250 CrossRef CAS.
D. M. Gordon and G. M. Whitesides, J. Org. Chem., 1993, 58, 7937–7938 CrossRef CAS.
E. Kim, D. M. Gordon, W. Schmid and G. M. Whitesides, J. Org. Chem., 1993, 58, 5500–5507 CrossRef CAS.
J. Gao, R. Haerter, D. M. Gordon and G. M. Whitesides, J. Org. Chem., 1994, 59, 3714–3715 CrossRef CAS.
M. D. Chappell and R. L. Halcomb, Org. Lett., 2000, 2, 2003–2005 CrossRef CAS PubMed.
M. Warwel and W.-D. Fessner, Synlett, 2000, 865–867 CAS.
T. H. Chan and C.-J. Li, Organometallics, 1990, 9, 2649–2650 CrossRef CAS.
C.-J. Li and T. H. Chan, Organometallics, 1991, 10, 2548–2549 CrossRef CAS.
B. M. Trost and S. A. King, J. Am. Chem. Soc., 1990, 112, 408–422 CrossRef CAS.
Y.-Q. Lu and C.-J. Li, Tetrahedron Lett., 1996, 37, 471–474 CrossRef CAS.
C.-J. Li, D.-L. Chen, Y.-Q. Lu, J. X. Haberman and J. T. Mague, J. Am. Chem. Soc., 1996, 118, 4216–4217 CrossRef CAS.
C.-J. Li, D.-L. Chen, Y.-Q. Lu, J. X. Haberman and J. T. Mague, Tetrahedron, 1998, 54, 2347–2364 CrossRef CAS.
C.-J. Li and D.-L. Chen, Synlett, 1999, 735–736 CrossRef CAS.
J. X. Haberman and C.-J. Li, Tetrahedron Lett., 1997, 38, 4735–4736 CrossRef CAS.
L. A. Paquette and T. M. Mitzel, J. Am. Chem. Soc., 1996, 118, 1931–1937 CrossRef CAS.
L. A. Paquette, Synthesis, 2003, 765–774 CrossRef CAS.
F. Márquez, R. Montoro, A. Llebaria, E. Lago, E. Molins and A. Delgado, J. Org. Chem., 2002, 67, 308–311 CrossRef.
T.-P. Loh and J.-R. Zhou, Tetrahedron Lett., 1999, 40, 9115–9118 CrossRef CAS.
T.-P. Loh and J.-R. Zhou, Tetrahedron Lett., 2000, 41, 5261–5264 CrossRef CAS.
Y.-C. Teo, E.-L. Goh and T.-P. Loh, Tetrahedron Lett., 2005, 46, 6209–6211 CrossRef CAS.
S. Kobayashi, N. Aoyama and K. Manabe, Chirality, 2003, 15, 124–126 CrossRef CAS PubMed.
U. Schneider, M. Ueno and S. Kobayashi, J. Am. Chem. Soc., 2008, 130, 13824–13825 CrossRef CAS PubMed.
T. M. Mitzel, C. Palomo and K. Jendza, J. Org. Chem., 2002, 67, 136–145 CrossRef CAS PubMed.
D. Prajapati, D. D. Laskar, B. J. Gogoi and G. Devi, Tetrahedron Lett., 2003, 44, 6755–6757 CrossRef CAS.
H. Miyabe, Y. Yamaoka, T. Naito and Y. Takemoto, J. Org. Chem., 2004, 69, 1415–1418 CrossRef CAS PubMed.
C. Zhou, J. Jiang, Y. Zhou, Z. Xie, Q. Miao and Z. Wang, Lett. Org. Chem., 2005, 2, 61–64 CrossRef CAS.
B. H. Lipshutz and S. Ghorai, Aldrichimica Acta, 2008, 41, 59 CAS.
M. Ueda and N. Miyaura, J. Org. Chem., 2000, 65, 4450–4452 CrossRef CAS PubMed.
C.-J. Li, Acc. Chem. Res., 2002, 35, 533–538 CrossRef CAS PubMed.
M. Sakai, M. Ueda and N. Miyaura, Angew. Chem., Int. Ed., 1998, 37, 3279–3281 CrossRef CAS PubMed.
K. Fagnou and M. Lautens, Chem. Rev., 2003, 103, 169–196 CrossRef CAS PubMed.
T. Yamamoto, T. Ohta and Y. Ito, Org. Lett., 2005, 7, 4153–4155 CrossRef CAS PubMed.
S. Lin and X. Lu, J. Org. Chem., 2007, 72, 9757–9760 CrossRef CAS PubMed.
T. Hayashi and K. Yamasaki, Chem. Rev., 2003, 103, 2829–2844 CrossRef CAS PubMed.
P. Tian, H.-Q. Dong and G.-Q. Lin, ACS Catal., 2012, 2, 95–119 CrossRef CAS.
X. Lu and S. Lin, J. Org. Chem., 2005, 70, 9651–9653 CrossRef CAS PubMed.
S. Lin and X. Lu, Org. Lett., 2010, 12, 2536–2539 CrossRef CAS PubMed.
K. Kikushima, J. C. Holder, M. Gatti and B. M. Stoltz, J. Am. Chem. Soc., 2011, 133, 6902 CrossRef CAS PubMed.
C.-G. Feng, M.-H. Xu and G.-Q. Lin, Synlett, 2011, 1345–1356 CAS.
C. L. Hawkins and M. J. Davies, Biochim. Biophys. Acta, Bioenerg., 2001, 1504, 196–219 CrossRef CAS.
M. Gutowski and S. Kowalczyk, Acta Biochim. Pol., 2013, 60, 1–16 CAS.
H. Yorimitsu, T. Nakamura, H. Shinokubo and K. Oshima, J. Org. Chem., 1998, 63, 8604–8605 CrossRef CAS.
H. Yorimitsu, T. Nakamura, H. Shinokubo, K. Oshima, K. Omoto and H. Fujimoto, J. Am. Chem. Soc., 2000, 122, 11041–11047 CrossRef CAS.
C. Petrier, C. Dupuy and J. L. Luche, Tetrahedron Lett., 1986, 27, 3149–3152 CrossRef CAS.
J. L. Luche and C. Allavena, Tetrahedron Lett., 1988, 29, 5369–5372 CrossRef CAS.
C. Dupuy, C. Petrier, L. A. Sarandeses and J. L. Luche, Synth. Commun., 1991, 21, 643–651 CrossRef CAS.
B. Giese, W. Damm, M. Roth and M. Zehnder, Synlett, 1992, 441–443 CrossRef CAS.
P. Erdmann, J. Schäfer, R. Springer, H.-G. Zeitz and B. Giese, Helv. Chim. Acta, 1992, 75, 638–644 CrossRef CAS.
J. L. Luche, C. Allavena, C. Petrier and C. Dupuy, Tetrahedron Lett., 1988, 29, 5373–5374 CrossRef CAS.
K. Michał Pietrusiewicz and M. Zabłocka, Tetrahedron Lett., 1988, 29, 937–940 CrossRef.
M. Roth, W. Damm and B. Giese, Tetrahedron Lett., 1996, 37, 351–354 CrossRef CAS.
R. M. Suárez, J. P. Sestelo and L. A. Sarandeses, Synlett, 2002, 1435–1438 Search PubMed.
R. M. Suárez, J. Pérez Sestelo and L. A. Sarandeses, Chem.–Eur. J., 2003, 9, 4179–4187 CrossRef PubMed.
T. Huang, C. C. K. Keh and C.-J. Li, Chem. Commun., 2002, 2440–2441 RSC.
C.-J. Li and W.-C. Zhang, J. Am. Chem. Soc., 1998, 120, 9102–9103 CrossRef CAS.
H. Miyabe, M. Ueda, A. Nishimura and T. Naito, Org. Lett., 2002, 4, 131–134 CrossRef CAS PubMed.
M. Ueda, H. Miyabe, A. Nishimura, O. Miyata, Y. Takemoto and T. Naito, Org. Lett., 2003, 5, 3835–3838 CrossRef CAS PubMed.
C. C. K. Keh, C. Wei and C.-J. Li, J. Am. Chem. Soc., 2003, 125, 4062–4063 CrossRef CAS PubMed.
Z.-L. Shen, Y.-L. Yeo and T.-P. Loh, J. Org. Chem., 2008, 73, 3922–3924 CrossRef CAS PubMed.
T. H. Chan, C.-J. Li and Z. Y. Wei, J. Chem. Soc., Chem. Commun., 1990, 505–507 RSC.
J.-Y. Zhou, Y. Jia, Q.-Y. Shao and S.-H. Wu, Synth. Commun., 1996, 26, 769–775 CrossRef CAS.
T. H. Chan, C.-J. Li, M. C. Lee and Z. Y. Wei, Can. J. Chem., 1994, 72, 1181–1192 CrossRef CAS.
P. H. Lee, K. Bang, K. Lee, S.-y. Sung and S. Chang, Synth. Commun., 2001, 31, 3781–3789 CrossRef CAS.
L. W. Bieber, I. Malvestiti and E. C. Storch, J. Org. Chem., 1997, 62, 9061–9064 CrossRef CAS.
W. J. Chung, S. Higashiya and J. T. Welch, J. Fluorine Chem., 2001, 112, 343–347 CrossRef CAS.
J. B. F. N. Engberts, in Methods and Reagents for Green Chemistry, ed. P. Tundo, A. Perosa and F. Zecchini, John Wiley & Sons, Inc., NJ, 2007, ch. 7, pp. 159–170 Search PubMed.
D. Torsten, P. Eckhard and O. Günther, Angew. Chem., Int. Ed., 2005, 44, 7174–7199 CrossRef PubMed.
T. Hamada, K. Manabe and S. Kobayashi, J. Am. Chem. Soc., 2004, 126, 7768–7769 CrossRef CAS PubMed.
B. H. Lipshutz, S. Huang, W. W. Y. Leong, G. Zhong and N. A. Isley, J. Am. Chem. Soc., 2012, 134, 19985–19988 CrossRef CAS PubMed.
B. H. Lipshutz and S. Ghorai, Aldrichimica Acta, 2012, 45, 3 CAS.
B. H. Lipshutz, S. Ghorai and M. Cortes-Clerget, Chem.–Eur. J., 2018, 24, 6672–6695 CrossRef CAS PubMed.
F. Zhou and C.-J. Li, Nat. Commun., 2014, 5, 4254 CrossRef CAS PubMed.
D. J. Lippincott, R. T. H. Linstadt, M. R. Maser, F. Gallou and B. H. Lipshutz, Org. Lett., 2018, 20, 4719–4722 CrossRef CAS PubMed.
L. Cicco, S. Sblendorio, R. Mansueto, F. M. Perna, A. Salomone, S. Florio and V. Capriati, Chem. Sci., 2016, 7, 1192–1199 RSC.
G. Dilauro, M. Dell'Aera, P. Vitale, V. Capriati and F. M. Perna, Angew. Chem., Int. Ed., 2017, 56, 10200–10203 CrossRef CAS PubMed.
J. García-Álvarez, E. Hevia and V. Capriati, Eur. J. Org. Chem., 2015, 6779–6799 CrossRef.
J. García-Álvarez, E. Hevia and V. Capriati, Chem.–Eur. J., 2018, 24, 14854–14863 CrossRef PubMed.
R. A. Sheldon, Chem. Soc. Rev., 2012, 41, 1437–1451 RSC.
J.-Q. Yu, L. Ackermann and Z. Shi, in C–H Activation, Topics in Current Chemistry, Springer, Berlin, 2010, ch. 292 Search PubMed.
P. H. Dixneuf and H. Doucet, in C–H Bond Activation and Catalytic Functionalization I Topics in Organometallic Chemistry, Springer, Cham, 2015 Search PubMed.
P. H. Dixneuf and H. Doucet, in C–H Bond Activation and Catalytic Functionalization II Topics in Organometallic Chemistry, Springer, Cham, 2016 Search PubMed.
C. I. Herrerías, X. Yao, Z. Li and C.-J. Li, Chem. Rev., 2007, 107, 2546–2562 CrossRef PubMed.
C. Wei and C.-J. Li, Green Chem., 2002, 4, 39–41 RSC.
C.-J. Li and C. Wei, Chem. Commun., 2002, 268–269 RSC.
C. Wei and C.-J. Li, J. Am. Chem. Soc., 2002, 124, 5638–5639 CrossRef CAS PubMed.
C. Wei and C.-J. Li, J. Am. Chem. Soc., 2003, 125, 9584–9585 CrossRef CAS PubMed.
(a) X. Yao and C.-J. Li, Org. Lett., 2005, 7, 4395–4398 CrossRef CAS PubMed; (b) C.-J. Li, Acc. Chem. Res., 2010, 43, 581–590 CrossRef CAS PubMed.
P. B. Arockiam, C. Fischmeister, C. Bruneau and P. H. Dixneuf, Angew. Chem., Int. Ed., 2010, 49, 6629–6632 CrossRef CAS PubMed.
L. Ackermann and A. V. Lygin, Org. Lett., 2012, 14, 764–767 CrossRef CAS PubMed.
M.-Z. Lu, P. Lu, Y.-H. Xu and T.-P. Loh, Org. Lett., 2014, 16, 2614–2617 CrossRef CAS PubMed.
H. Gong, H. Zeng, F. Zhou and C.-J. Li, Angew. Chem., Int. Ed., 2015, 54, 5718–5721 CrossRef CAS PubMed.
B. Wang, W. A. Nack, G. He, S.-Y. Zhang and G. Chen, Chem. Sci., 2014, 5, 3952–3957 RSC.
J. Hu, T. Lan, Y. Sun, H. Chen, J. Yao and Y. Rao, Chem. Commun., 2015, 51, 14929–14932 RSC.
G. Deng and C.-J. Li, Tetrahedron Lett., 2008, 49, 5601–5604 CrossRef CAS.
D. Seebach and E. J. Corey, J. Org. Chem., 1975, 40, 231–237 CrossRef CAS.
B.-T. GrÖBel and D. Seebach, Synthesis, 1977, 357–402 CrossRef.
S. Gustavo, Curr. Org. Chem., 2000, 4, 283–304 Search PubMed.
J. Sukumaran and U. Hanefeld, Chem. Soc. Rev., 2005, 34, 530–542 RSC.
M. Pohl, G. A. Sprenger and M. Müller, Curr. Opin. Biotechnol., 2004, 15, 335–342 CrossRef CAS PubMed.
R. S. Menon, A. T. Biju and V. Nair, Beilstein J. Org. Chem., 2016, 12, 444–461 CrossRef CAS PubMed.
D. Enders and T. Balensiefer, Acc. Chem. Res., 2004, 37, 534–541 CrossRef CAS PubMed.
H. Wang, X.-J. Dai and C.-J. Li, Nat. Chem., 2016, 9, 374–378 CrossRef PubMed.
N. Chen, X.-J. Dai, H. Wang and C.-J. Li, Angew. Chem., Int. Ed., 2017, 56, 6260–6263 CrossRef CAS PubMed.
X.-J. Dai, H. Wang and C.-J. Li, Angew. Chem., Int. Ed., 2017, 56, 6302–6306 CrossRef CAS PubMed.
L. Lv, D. Zhu, J. Tang, Z. Qiu, C.-C. Li, J. Gao and C.-J. Li, ACS Catal., 2018, 8, 4622–4627 CrossRef CAS.

References: V. 

V. 
 V. 
 V. 
 V. 
 V. 
 V. 
 V. 
 V. 
 V.