Highly enantioselective 1,4-addition of arylzinc reagents to 3-arylpropenals catalyzed by a rhodium–binap complex in the presence of chlorotrimethylsilane
摘要:
Asymmetric 1,4-addition of arylzinc chlorides to (E)-3-arylpropenals proceeded with high enantioselectivity in the presence of a rhodium/(R)-binap catalyst and chlorotrimethylsilane to give, after hydrolysis, high yields of the corresponding 3.3-diarylpropanals of 98-99% ee. The presence of the chlorosilane is essential for high yields of the 1,4-addition products. (c) 2006 Elsevier Ltd. All rights reserved.
alkylthiolation of alkenes, initiated by dimethyl(methylthio)sulfonium salts and the subsequent addition of various heteronucleophilies has been well-established. Regarding the use of carbon nucleophiles, however, only carefully designed sp-type carbon sources have been successfully applied. We herein present our findings on the methylthiolation of alkenes with dimethyl(methylthio)sulfonium trifluoromethanesulfonate
An Interrupted Pummerer/Nickel-Catalysed Cross-Coupling Sequence
作者:Miles H. Aukland、Fabien J. T. Talbot、José A. Fernández-Salas、Matthew Ball、Alexander P. Pulis、David J. Procter
DOI:10.1002/anie.201805396
日期:2018.7.26
An interrupted Pummerer/nickel‐catalysedcross‐coupling strategy has been developed and used in the elaboration of styrenes. The operationally simple method can be carried out as a one‐pot process, involves the direct formation of stable alkenyl sulfonium salt intermediates, utilises a commercially available sulfoxide, catalyst, and ligand, operates at ambient temperature, accommodates sp‐, sp2‐, and
Stereoconvergent Negishi Arylations of Racemic Secondary Alkyl Electrophiles: Differentiating between a CF<sub>3</sub> and an Alkyl Group
作者:Yufan Liang、Gregory C. Fu
DOI:10.1021/jacs.5b04725
日期:2015.8.5
wide array of enantioconvergent cross-couplings of arylzincreagents with CF3-substituted racemic secondary alkyl halides, a process that necessitates that the chiral catalyst be able to effectively distinguish between a CF3 and an alkyl group in order to provide good ee. We further demonstrate that this method can be applied without modification to the catalyticasymmetric synthesis of other families
Rhodium-Catalyzed Desymmetric Arylation of <i>γ,γ</i>-Disubsituted Cyclohexadienones: Asymmetric Synthesis of Chiral All-Carbon Quaternary Centers
作者:Yu Qiao、Shiming Bai、Xiao-Feng Wu、Ying Yang、He Meng、Jialin Ming
DOI:10.1021/acs.orglett.2c00225
日期:2022.2.25
desymmetric arylation of prochiral cyclohexadienones with ArZnCl in the presence of an (R)-segphos–rhodium catalyst gave high yields of the corresponding cyclohexenones, which contain a chiral arylated carbon center at the β-position and a chiral all-carbon quaternary center at the γ-position, with high diastereo- and enantioselectivities. This catalytic system was also applied to the arylation of spirocarbocyclic
在 ( R )-segphos-铑催化剂存在下,前手性环己二烯酮与 ArZnCl 的不对称芳基化得到高产率的相应环己烯酮,其在β位含有手性芳基化碳中心,在γ-位,具有高非对映选择性和对映选择性。该催化体系还应用于螺碳环环己二烯酮的芳基化,并提供了相应的带有高 dr 和 ee 的手性螺季碳的环己烯酮。
Transition metal catalysed cross-coupling between benzylic halides and aryl nucleophiles. Synthesis of some toxicologically interesting tetrachlorobenzyltoluenes.
作者:Robert-Jan de Lang、Marcel J.C.M. van Hooijdonk、Lambert Brandsma、Hester Kramer、Willem Seinen
DOI:10.1016/s0040-4020(98)83030-5
日期:1998.3
The aryl-benzyl cross-coupling in the presence of copper-, nickel-and palladium-catalysts has been investigated with a number of chlorine-and methyl-substituted arylmetal compounds ArM (M= MgBr, ZnCl) and (substituted) benzylic halides ArCH2X. The results have been applied in the selective synthesis of some toxicologically interesting tetrachlorobenzyltoluenes. (C) 1998 Elsevier Science Ltd. All rights reserved.