bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response Surface Optimization of Essential Oil and Diosgenin Extraction from Tribulus terrestris via Supercritical Fluid Technology
Authors: Ghoreishi S. M. , Bataghva E. , Dadkhah A. A. 
Published: September 2011

AbstractFour operating parameters of supercritical carbon dioxide extraction were optimized by the response surface method. The central composite rotatable design was used to maximize extraction recovery of essential oil (specifically diosgenin) from Tribulus terrestris. The obtained data were adequately fitted into two second‐order polynomial models for essential oil and diosgenin. The linear terms of pressure, temperature, and extraction dynamic time, the quadratics of pressure and extraction dynamic time, and the interactions of the following two variables: (i) pressure and temperature, (ii) pressure and extraction dynamic time, and (iii) temperature and extraction dynamic time had significant effects on diosgenin recovery.
Size‐Dependent Phase Stability of a Molecular Nanocrystal: a Proxy for Investigating the Early Stages of Crystallization
Authors: Zahn Dirk , Anwar Jamshed 
Published: September 2011

AbstractWe make the link between the size‐dependent phase stability of a nanocrystal and the phase‐transition behavior of emerging crystallites during the earliest stages of crystallization, by using the former as a proxy for the latter. We outline an extension of the classical nucleation theory to describe crystal nucleation and subsequent transformations of competing polymorphic phases that characterize Ostwald’s rule of stages. The theoretical framework reveals that the relative stability of the competing phases is a function of cluster size, which in turn varies with time, and therefore explains the complex transformation behavior observed for some systems. We investigated the stability of a nanocrystal of dl‐norleucine by means of molecular simulation as a proxy for post‐nucleation phase‐transformation behavior in emerging crystallites. The simulations reveal that, for nanocrystals, the surface energy of the transition state of a transformation can dominate the barrier to phase change, thus causing metastable phases to be stabilized, not because they are thermodynamically stable, but rather due to kinetic hindering. Therefore, in the context of the earliest stages of crystal growth, not only does phase stability vary as a function of cluster size, and hence time, but thermodynamically feasible transformations are also prone to kinetic hindering.
Conformational Selection of the AGA*IAM Heparin Pentasaccharide when Bound to the Fibroblast Growth Factor Receptor
Authors: Nieto Lidia , Canales Ángeles , Giménez‐Gallego Guillermo , Nieto Pedro M. , Jiménez‐Barbero Jesús 
Published: September 2011

AbstractThe interaction of the synthetic pentasaccharide AGA*IAM (GlcNS,6S‐GlcA‐GlcNS,3S,6S‐IdoA2S‐GlcNS,6S‐Me) with the extracellular Ig2 domain of the fibroblast growth factor receptor (FGFR2) has been studied by NMR and computational methods. Analysis of the heparin pentasaccharide in the free state and in the complex indicates the existence of a conformational selection process. Although an equilibrium exists between the 1C4 and 2S0 conformers (ratio 60:40) of the 2‐O‐sulfo‐α‐L‐iduronate ring (IdoA2S) in the free state, FGFR2 selects only the unique twisted‐boat 2S0 conformation of this IdoA2S residue. In addition, the protein residues involved in the binding with AGA*IAM have also been characterized. The NMR results obtained, from both the ligand and protein perspective, were employed to model the bound conformation of the pentasaccharide by a combined docking and molecular dynamic simulation approach.
New Perspectives on Iron–Ligand Vibrations of Oxyheme Complexes
Authors: Li Jianfeng , Peng Qian , Barabanschikov Alexander , Pavlik Jeffrey W. , Alp E. Ercan , Sturhahn Wolfgang , Zhao Jiyong , Schulz Charles E. , Sage J. Timothy , Scheidt W. Robert 
Published: September 2011

AbstractWe report our studies of the vibrational dynamics of iron for three imidazole‐ligated oxyheme derivatives that mimic the active sites of histidine‐ligated heme proteins complexed with dioxygen. The experimental vibrational data are obtained from nuclear resonance vibrational spectroscopy (NRVS) measurements conducted on both powder samples and oriented single crystals, and which includes several in‐plane (ip) and out‐of‐plane (oop) measurements. Vibrational spectral assignments have been made through a combination of the oriented sample spectra and predictions based on density functional theory (DFT) calculations. The two Fe–O2 modes that have been previously observed by resonance Raman spectroscopy in heme proteins are clearly shown to be very strongly mixed and are not simply either a bending or stretching mode. In addition, a third Fe–O2 mode, not previously reported, has been identified. The long‐sought Fe–Im stretch, not observed in resonance Raman spectra, has been identified and compared with the frequencies observed for the analogous CO and NO species. The studies also suggest that the in‐plane iron motion is anisotropic and is controlled by the orientation of the Fe–O2 group and not sensitive to the in‐plane FeNp bonds and/or imidazole orientations.
Enantioselective and Diastereoselective Tsuji–Trost Allylic Alkylation of Lactones: An Experimental and Computational Study
Authors: Meletis Panos , Patil Mahendra , Thiel Walter , Frank Walter , Braun Manfred 
Published: September 2011

AbstractThe Tsuji–Trost protocol has been successfully employed for the allylic alkylation of preformed lactone enolates. It has been demonstrated that this Pd‐catalyzed reaction can be carried out in an enantio‐ and diastereoselective manner. The use of additives, such as LiCl, was found to be crucial for reaching high levels of product selectivity. For one particular pair of reactants, density functional theory was used to investigate the mechanism of the nucleophilic addition. Among the five pathways considered, the reaction between an (allyl)Pd(BINAP) complex and a LiCl–lithium enolate adduct is predicted to be the most likely route for CC bond formation. LiCl plays a key role as the connecting link between the noble metal and the enolate in the kinetically favored transition state. The computed diastereoselectivity ratio is in good agreement with the experimentally observed value.
Visible–Near‐Infrared and Fluorescent Copper Sensors Based on Julolidine Conjugates: Selective Detection and Fluorescence Imaging in Living Cells
Authors: Maity Debabrata , Manna Arun K. , Karthigeyan D. , Kundu Tapas K. , Pati Swapan K. , Govindaraju T. 
Published: September 2011

AbstractWe present novel Schiff base ligands julolidine–carbonohydrazone 1 and julolidine–thiocarbonohydrazone 2 for selective detection of Cu2+ in aqueous medium. The planar julolidine‐based ligands can sense Cu2+ colorimetrically with characteristic absorbance in the near‐infrared (NIR, 700–1000 nm) region. Employing molecular probes 1 and 2 for detection of Cu2+ not only allowed detection by the naked eye, but also detection of varying micromolar concentrations of Cu2+ due to the appearance of distinct coloration. Moreover, Cu2+ selectively quenches the fluorescence of julolidine–thiocarbonohydrazone 2 among all other metal ions, which increases the sensitivity of the probe. Furthermore, quenched fluorescence of the ligand 2 in the presence of Cu2+ was restored by adjusting the complexation ability of the ligand. Hence, by treatment with ethylenediaminetetraacetic acid (EDTA), thus enabling reversibility and dual‐check signaling, julolidine–thiocarbonohydrazone (2) can be used as a fluorescent molecular probe for the sensitive detection of Cu2+ in biological systems. The ligands 1 and 2 can be utilized to monitor Cu2+ in aqueous solution over a wide pH range. We have investigated the structural, electronic, and optical properties of the ligands using ab initio density functional theory (DFT) combined with time‐dependent density functional theory (TDDFT) calculations. The observed absorption band in the NIR region is attributed to the formation of a charge‐transfer complex between Cu2+ and the ligand. The fluorescence‐quenching behavior can be accounted for primarily due to the excited‐state ligand 2 to metal (Cu2+) charge‐transfer (LMCT) processes. Thus, experimentally observed characteristic NIR and fluorescence optical responses of the ligands upon binding to Cu2+ are well supported by the theoretical calculations. Subsequently, we have employed julolidine–thiocarbonohydrazone 2 for reversible fluorescence sensing of intracellular Cu2+ in cultured HEK293T cells.
ChemInform Abstract: Transitions Between Lanthanum Cuprates: Crystal Structures of T′, Orthorhombic, and K2NiF4‐Type La2CuO4.
Authors: Hord Roland , Cordier Gerhard , Hofmann Kathrin , Buckow Alexander , Pascua Gwendolyne , Luetkens Hubertus , Alff Lambert , Albert Barbara 
Published: September 2011

AbstractMetastable T′ La2CuO4 (tetragonal, space group I4/mmm) is obtained from a stoichiometric mixture of CuO and La2O3 in a CsOH flux at 653 K (24 h).
ChemInform Abstract: Copper(I) d10···d10 Interactions and Diselenide(1‐) Radical Anions in Mixed Valent Selenides Cu4‐δBiSe4I.
Authors: Heerwig Andreas , Isaeva Anna , Ruck Michael 
Published: September 2011

AbstractBlack needles of Cu4BiSe4I are prepared from a mixture of Cu, CuI, Se, and Bi2Se3 (570 K, 14 d) and characterized by single crystal XRD, Raman spectroscopy, electrical conductivity measurements, and DFT calculations.
ChemInform Abstract: Solution Synthesis of Nanoparticular Binary Transition Metal Antimonides.
Authors: Kieslich Gregor , Birkel Christina S. , Stewart Andrew , Kolb Ute , Tremel Wolfgang 
Published: September 2011

AbstractThe transition metal antimonides MSb with M: Co, Ni, and Zn and Cu2Sb with particle sizes ranging from 20 to 60 nm are prepared using presynthesized antimony nanoparticles and activated metal nanoparticles as precursors.
ChemInform Abstract: Cs10Tl6SiO4, Cs10Tl6GeO4 and Cs10Tl6SnO3 — First Oxotetrelate Thallides, Double Salts Containing “Hypoelectronic” [Tl6]6‐ Clusters.
Authors: Saltykov Vyacheslav , Nuss Juergen , Jansen Martin 
Published: September 2011

AbstractThe title compounds are prepared from mixtures of Cs, Cs2O, Tl, and SiO2, GeO2, or Sn (sealed Ta tubes, 623—773 K, 2—3 d,).
ChemInform Abstract: Synthesis and Crystal Structure of the Fluoride‐Rich Rubidium Scandium Fluoride Oxosilicate Rb3Sc2F5Si4O10.
Authors: Schaefer Marion C. , Schleid Thomas 
Published: September 2011

AbstractSingle crystals of the title compound are synthesized by reaction of ScF3, Sc2O3, SiO2, excess RbF as a flux and Rb source, and B2O3 as mineralization agent (sealed Pt ampule, 700 °C, 17 d).
ChemInform Abstract: Iron Dihydride Complex as the Pre‐Catalyst for Efficient Hydrosilylation of Aldehydes and Ketones under Visible Light Activation.
Authors: Misal Castro Luis C. , Bezier David , Sortais Jean‐Baptiste , Darcel Christophe 
Published: September 2011

AbstractAfter subsequent desilylation a wide range of primary and secondary alcohols is available in good to high yields.
ChemInform Abstract: Efficient and Controllably Selective Preparation of Esters Using Uronium‐Based Coupling Agents.
Authors: Twibanire Jean‐d'Amour K. , Grindley T. Bruce 
Published: September 2011

AbstractA wide range of esters is prepared from primary, secondary or tertiary alcohols or diols and simple and complex carboxylic acids, including carbohydrate‐derived acids and alcohols in the presence of coupling reagents and a base.
ChemInform Abstract: Acetic Anhydride/Et3N/DMAP: An Effective Acetylating System for Hemiacetals.
Authors: Roncaglia Fabrizio , Parsons Andrew F. , Bellesia Franco , Ghelfi Franco 
Published: September 2011

AbstractA new and more efficient method for the practical multigram preparation of O‐allyl‐2,2‐dichlorohemiacetal acetates (IV) from 2,2‐dichloroaldehydes, allylic alcohols and acetic anhydride is developed.
ChemInform Abstract: Copper(I) Iodide Catalyzed Cross‐Coupling Reaction of Terminal Alkynes with 1‐Bromoalkynes: A Simple Synthesis of Unsymmetrical Buta‐1,3‐diynes.
Authors: Wang Shihua , Yu Lin , Li Pinhua , Meng Lingguo , Wang Lei 
Published: September 2011

AbstractA novel approach to a broad spectrum of target compounds becomes possible under experimentally simple conditions and gives generally good to excellent yields.
ChemInform Abstract: Carbonyl Allylation of Aldehydes and Ketones with Allylic Chlorides Catalyzed by Immobilization of Palladium in MCM‐41.
Authors: Zhao Hong , Peng Jian , Xiao Ruian , Hao Wenyan , Cai Ming‐Zhong 
Published: September 2011

AbstractAromatic and aliphatic aldehydes and ketones react with allyl and methallyl chloride to provide the desired alcohols.
ChemInform Abstract: A Novel Highly Stereoselective Multi‐Component Synthesis of N‐Substituted β‐Amino Ketone Derivatives Using Copper(II) Phthalocyanine as Reusable Catalyst.
Authors: Shinu V. S. , Pramitha P. , Bahulayan D. 
Published: September 2011

AbstractA copper(II) phthalocyanine‐mediated one‐pot stereoselective process for the synthesis of a variety of N‐substituted β‐amino ketone derivatives (IV) and (VII) is reported.
ChemInform Abstract: Enantiopure α‐Imino Glyoxylate: A Versatile Substrate for the Spontaneous Asymmetric Synthesis of Unnatural Hydroxyaryl Glycinates.
Authors: Cimarelli Cristina , Fratoni Davide , Mazzanti Andrea , Palmieri Gianni 
Published: September 2011

AbstractThe presence of a hydroxy group is crucial as 2‐methoxynaphthalene fails to react.
ChemInform Abstract: Rhodium‐Catalyzed Asymmetric Hydrogenation of β‐Acetylamino Acrylonitriles.
Authors: Ma Miaofeng , Hou Guohua , Wang Junru , Zhang Xumu 
Published: September 2011

AbstractHydrogenation of the title compounds proceeds best when catalyzed according to A), whether the substrates are applied in pure isomeric form or as isomeric mixtures.
ChemInform Abstract: Lewis Acids as Co‐reagents in Sulfenylation Reactions.
Authors: Zyk N. V. , Gavrilova A. Yu. , Mukhina O. A. , Bondarenko O. B. , Zefirov N. S. 
Published: September 2011

AbstractSulfenylation of alkenes with benzenesulfenate (II) in the presence of Lewis acids allows control of the product composition by varying the reaction conditions.
ChemInform Abstract: Rhenium‐Catalyzed Regio‐ and Stereoselective Addition of Two Carbon Units to Terminal Alkynes via Carbon—Carbon Bond Cleavage of β‐Keto Sulfones.
Authors: Kuninobu Yoichiro , Matsuzaki Hironori , Nishi Mitsumi , Takai Kazuhiko 
Published: September 2011

AbstractThe insertion takes place between the α‐ and β‐positions of the β‐keto sulfones and (Z)‐isomers are produced highly selectively.
ChemInform Abstract: In situ Synthesis of a Palladium‐Polyaniline Hybrid Catalyst for a Suzuki Coupling Reaction.
Authors: Ul Islam Rafique , Witcomb Michael J. , van der Lingen Elma , Scurrell Michael S. , Van Otterlo Willem , Mallick Kaushik 
Published: September 2011

AbstractThe catalyst, generated in situ from aniline hydrochloride and Pd(OAc)2, promotes effectively the coupling of a variety of aryl bromides and iodides with phenyl boronic acids.
ChemInform Abstract: Palladium‐Catalyzed Decarboxylative Arylation of Potassium Cyanoacetate: Synthesis of α‐Diaryl Nitriles from Aryl Halides.
Authors: Yeung Pui Yee , Chung Kin Ho , Kwong Fuk Yee 
Published: September 2011

AbstractIn most cases, potassium cyanoacetate (I) produces higher yields than its sodium analogue (VIII).
ChemInform Abstract: tert‐Butanesulfinylthioether Ligands: Synthesis and Application in Palladium‐Catalyzed Asymmetric Allylic Alkylation.
Authors: Liu Jibing , Chen Guihua , Xing Junwei , Liao Jian 
Published: September 2011

AbstractThe method acts best when catalyzed by (I).
ChemInform Abstract: Directed Arylation of Heteroaromatic Compounds with Congested, Functionalized Aryl Bromides at Low Palladium/Triphosphane Catalyst Loading.
Authors: Roy David , Mom Sophal , Lucas Dominique , Cattey Helene , Hierso Jean‐Cyrille , Doucet Henri 
Published: September 2011

AbstractThe catalyst system is found to be highly effective in a 1:1 ratio at 0.05‐1 mol%, where in most cases 0.5 mol% are used.
ChemInform Abstract: Synthesis of Functionalized Iminolactones via an Isocyanide‐Based Three‐Component Reaction.
Authors: Sarvary Afshin , Shaabani Shabnam , Shaabani Ahmad , Ng Seik Weng 
Published: September 2011

AbstractThe zwitterionic intermediates, generated from isocyanides (II) and alkynes (III) by a Michael‐type addition, are trapped by aryl ketones (I) bearing an electron‐withdrawing group either at the α‐position of the carbonyl group or in para‐position of the aryl group.
ChemInform Abstract: Phosphine‐Catalyzed [3 + 2] Annulations of γ‐Functionalized Butynoates and 1C,3O‐Bisnucleophiles: Highly Selective Reagent‐Controlled Pathways to Polysubstituted Furans.
Authors: Hu Jian , Wei Yabing , Tong Xiaofeng 
Published: September 2011

AbstractButynoate (I) reacts with bisnucleophiles according to A) via γ‐substitution to generate furan derivatives of type (III).
ChemInform Abstract: Modular Synthesis and Photophysical and Electrochemical Properties of 2,3,5,6‐Tetraaryl‐Substituted Benzo[1,2‐b:5,4‐b′]difurans.
Authors: Tsuji Hayato , Mitsui Chikahiko , Sato Yoshiharu , Nakamura Eiichi 
Published: September 2011

AbstractThe compounds (III) and (V) have high charge carrier mobility up to 1 x 10 ‐3 cm2/Vs, which makes them attractive as materials for organoelectronics applications.
ChemInform Abstract: Synthesis of N‐Arylisatins by the Reaction of Arynes with Methyl 2‐Oxo‐2‐(arylamino)acetates.
Authors: Rogness Donald C. , Larock Richard C. 
Published: September 2011

AbstractAdditionally, it is shown that the keto analogue (VIII) provides the 3‐hydroxyoxindole (IXa).
ChemInform Abstract: Cascade Intramolecular N‐Arylation/Intermolecular Carboamination Reactions for the Construction of Tricyclic Heterocycles.
Authors: Lemen Georgia S. , Wolfe John P. 
Published: September 2011

AbstractRacemic and chiral heterocyclic skeletons are constructed using a proper choice of Pd salt and a ligand.
ChemInform Abstract: Efficient Microwave‐Assisted Synthesis and Antitumor Activity of Novel 4,4′‐Methylenebis[2‐(3‐aryl‐4,5‐dihydro‐1H‐pyrazol‐5‐yl)phenols].
Authors: Insuasty Braulio , Garcia Angelica , Quiroga Jairo , Abonia Rodrigo , Ortiz Alejandro , Nogueras Manuel , Cobo Justo 
Published: September 2011

AbstractTwo novel series of title bis(diarylpyrazoline) derivatives are synthesized by microwave‐assisted cyclocondensation of methylene‐bischalcones (I) with hydrazine hydrate.
ChemInform Abstract: New Substituted Thiazol‐2‐ylidene‐benzamides and Their Reaction with 1‐Aza‐2‐azoniaallene Salts. Synthesis and anti‐HIV Activity.
Authors: Saeed Aamer , Al‐Masoudi Najim A. , Ahmed Amjed A. , Pannecouque Christophe 
Published: September 2011

Abstract20 Title compounds of type (III) are prepared and tested for their anti‐HIV activities.
ChemInform Abstract: Selective Formation of 1,5‐Substituted Sulfonyl Triazoles Using Acetylides and Sulfonyl Azides.
Authors: Meza‐Avina Maria Elena , Patel Mudita Kishor , Lee Cylivia B. , Dietz Thomas J. , Croatt Mitchell P. 
Published: September 2011

AbstractWhen being purified by silica gel chromatography, isomerization of the products to 1,4‐triazoles partially occurs.
ChemInform Abstract: Unprecedented Cu‐Catalyzed Coupling of Internal 1,3‐Diynes with Azides: One‐Pot Tandem Cyclizations Involving 1,3‐Dipolar Cycloaddition and Carbocyclization Furnishing Naphthotriazoles.
Authors: Mandadapu Anil K. , Sharma Sudhir K. , Gupta Sahaj , Krishna Deevi G. Venkata , Kundu Bijoy 
Published: September 2011

AbstractA variety of target compounds is prepared from aromatic symmetrical internal diynes and aromatic and aliphatic azides.
ChemInform Abstract: Highly Stereoselective Broensted Acid Catalyzed Synthesis of Spirooxindole Pyrans.
Authors: Wang Jingqi , Crane Erika A. , Scheidt Karl A. 
Published: September 2011

AbstractPrins‐type cyclization of β‐hydroxy dioxinones and isatin dimethylacetals is used to construct the title skeletons with complete diastereoselectivity.
ChemInform Abstract: A Novel Organozinc Reagent 4‐Coumarinylzinc Bromide; Preparation and Application in the Synthesis of 4‐Substituted Coumarin Derivatives.
Authors: Rieke Reuben D. , Kim Seung‐Hoi 
Published: September 2011

AbstractA novel organozinc reagent (I) is prepared by the direct oxidative addition of active zinc to 4‐bromocoumarin.
ChemInform Abstract: An Efficient One‐Pot Synthesis of Flavones.
Authors: Chee Chin Fei , Buckle Michael J. C. , Rahman Noorsaadah Abd. 
Published: September 2011

AbstractFlavones are prepared from the corresponding hydroxy‐acetophenones (I) and aroyl chlorides (II) to afford a good yield of flavones (III) and a smaller amount of 3‐aroylflavones (IV).
ChemInform Abstract: Synthesis of Functionalized CF3‐Containing Heterocycles via [2,3]‐Sigmatropic Rearrangement and Sequential Catalytic Carbocyclization.
Authors: Vorobyeva Daria V. , Mailyan Artur K. , Peregudov Alexander S. , Karimova Natalia M. , Vasilyeva Tamara P. , Bushmarinov Ivan S. , Bruneau Christian , Dixneuf Pierre H. , Osipov Sergey N. 
Published: September 2011

AbstractCopper‐catalyzed tandem ylide formation—[2,3]‐sigmatropic rearrangement of CF3‐containing diazo compounds (II) with amines and sulfides containing two allyl and/or propargyl groups, e.g. (I), (V), (IX) or (XIII), affords the corresponding dienes, enynes or allenynes.
ChemInform Abstract: Novel Synthetic Methodologies. Part 206. Molybdenum‐ and Tungsten‐Based Coordination Polymers as Catalysts for an Efficient and Rapid Synthesis of Hexahydro‐5‐oxoquinoline‐3‐carboxylates and 1,4‐Dihydropyridine‐3,5‐dicarboxylates.
Authors: Das Biswanath , Srilatha Malampati , Veeranjaneyulu Boyapati , Kanth Boddu Shashi 
Published: September 2011

AbstractAlmost equally active is the respective tungsten‐based catalyst.
ChemInform Abstract: α‐Dimethylaminomethylenation‐Induced Houben—Hoesch‐Type Cyclization of Cyanoacetanilides: A Practical Synthesis of 3‐Formyl‐4‐hydroxyquinolin‐2(1H)‐ones.
Authors: Kobayashi Yusuke , Nakatani Terue , Tanaka Rie , Okada Mari , Torii Eri , Harayama Takashi , Kimachi Tetsutaro 
Published: September 2011

AbstractThe triflic acid‐mediated cyclization of cyanoacetanilides (I) in DMF to give title formylquinolinones (III) is studied.
ChemInform Abstract: Stable Azomethine Imines Having a 3,4‐Dihydroisoquinoline Fragment and Their Cycloaddition to N‐Arylmaleimides.
Authors: Koptelov Yu. B. , Saik S. P. , Molchanov A. P. 
Published: September 2011

Abstract1,3‐Dipolar cycloaddition of N‐arylmaleimides (IV) to azomethine imines (III) leads to cis‐ and trans‐adducts (V) and (VI) in ratios depending on the ortho substituent in the aryl moiety of (IV).
ChemInform Abstract: Diastereoselective Intramolecular Friedel—Crafts Alkylation of Tetralins.
Authors: Liebert Clemence , Brinks Marion K. , Capacci Andrew G. , Fleming Matthew J. , Lautens Mark 
Published: September 2011

AbstractA wide range of cis‐hexahydrobenzophenanthridine‐derived cyclic compounds is prepared in a mild reaction from the corresponding chiral tetralin substrates with retention of optical purity.
ChemInform Abstract: An Efficient Synthesis of 1‐Thia‐5‐azaspiro[5.5]undec‐2‐ene and Its Recyclization to 1,5‐Diazaspiro[5.5]undec‐2‐ene and/or Spiro‐Thieno[2,3‐d]pyrimidin‐4(1H)‐one Derivatives.
Authors: Shaker Raafat M. , Hamoda Asmaa , Ibrahim Yusria R. , El‐Shaieb Kamal M. , Abdel‐Latif Fathy F. 
Published: September 2011

AbstractSpiro compound (III) is used as key intermediate for the synthesis of a series of derivatives.
ChemInform Abstract: New Efficient Synthesis of 2,3,4‐Trisubstituted 3,4‐Dihydroquinazolines by a Ugi 4CC/Staudinger/Aza‐Wittig Sequence.
Authors: Zhong Ying , Wang Long , Ding Ming‐Wu 
Published: September 2011

AbstractThe azide products are transformed at room temperature by the Staudinger reaction into intermediate iminophosphoranes which undergo an aza‐Wittig reaction under to give the desired quinazolines.