A2-08

Cooperative Catalyses of Transition Metal Anion andTypical Metal Cation

Takanori Iwasaki (Graduate School of Engineering, The University of Tokyo)
The anionic transition metal complexes, so-called ate complexes and their potent catalytic activities
remained undeveloped in sharp contrast with neutral and cationic transition metal complexes. Since the atecomplexes are synthesized in situ by reacting transition metal complexes with organometallic reagents such asorganolithium and -magnesium reagents, the ate complexes consist with transition metal anion and Lewis acidic
typical metal cation. We hypothesized that the anionic charge on transition
metal center activates metal center itself and own ligands as nucleophile, andthe counter cation coordinates to leaving group in substrates. In addition, these
metal centers are closely coexisted by electrostatic interaction leading tokinetic activation of substrates (Figure 1). These thermodynamic and kinetic
activations indeed enable carbon-carbon bond formations via the cleavage ofstrong chemical bonds such as C–F and C–O bonds.
When alkyl fluorides were used as carbon electrophiles, cross-coupling reaction with sterically congested
tertiary alkyl Grignard reagents,1 regioselective hydroalkylation of 1,3-dienes,2 and dimerizative alkylarylationof 1,3-butadiene3 were achieved. In these reactions, alkyl fluorides gave the best results among alkyl(pseudo)halides. Mechanistic studies indicated that Lewis acidic counter cation of the ate complexes efficientlyactivates C(sp3)–F bond, one of the strongest single bonds in organic compounds.4
Another representative reactivity of the ate complexes is the bond cleavage of ethereal C–O bond at the vinylic
position realizing cross-coupling reaction of alkenyl ethers with aryl Grignard reagents.5,6 Interestingly, morereactive C(sp2)–Br bond in aromatic ring survived under the reaction conditions.
Some of these ate complexes were successfully isolated and determined their molecular structures andchemical behavior.3–5,7,81) T. Iwasaki et al. Org. Lett. 2017, 19, 3691. 2) T. Iwasaki et al. Angew. Chem. Int. Ed. 2015, 54, 9347. 3) T.
Iwasaki et al. Angew. Chem. Int. Ed. 2016, 55, 5550. 4) T. Iwasaki et al. Chem. Sci. 2018, 9, 2195. 5) T. Iwasakiet al. J. Am. Chem. Soc. 2014, 136, 9260. 6) T. Iwasaki, Chem. Asian J. 2016, 11, 2834. 7) T. Iwasaki et al.
Organometallics 2020, 39, 3077. 8) T. Iwasaki et al. under revision.
PROFILE
Takanori Iwasaki (Graduate School of Engineering, The University of Tokyo)
He finished his BSc in 2004 and MSc in 2006 at Graduate School of Engineering Science, Osaka University and received
his Ph.D. in 2009 from Osaka University under the supervision of Profs K. Mashima and T. Ohshima. During his Ph.D.
course, he worked with Prof K. Kirchner, Vienna University of Technology, Austria in 2004. He became an AssistantProfessor at Graduate School of Engineering, Osaka University in 2009, working with Prof N. Kambe. He was promoted toAssociate Professor at Osaka University in 2017 and was appointed as Associate Professor at Graduate School ofEngineering, The University of Tokyo in 2018. His research interests include the development of multi-metallic catalyticsystems for the cooperative activation of substrates toward challenging transformations. He received a number ofdistinguished young investigator’s awards including Chemistry Award BCA 2018, Incentive Award in Synthetic OrganicChemistry, Japan in 2018, Thieme Chemistry Journals Award 2019, The Japan Petroleum Institute Award for Encouragementof Research and Development in 2019, The SPACC Young Investigator Award in 2019, The Commendation for Science andTechnology by MEXT, The Young Scientists' Award in 2020, The 2020 Mitsui Chemicals Catalysis Science Award for
Creative Work, and Research Incentive Award of Japan Society of Coordination Chemistry in 2020. E-mail:iwasaki@chembio.t.u-tokyo.ac.jp

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