Benzaldimines as ligands for palladium in Suzuki–Miyaura reactions
摘要:
Schiff bases derived from substituted benzaldehydes are effective ligands for palladium(0) in the Suzuki-Miyaura coupling of phenylboronic acid with aryl, benzyl and allyl bromides under mild conditions. (c) 2008 Elsevier Ltd. All rights reserved.
Benzaldimines as ligands for palladium in Suzuki–Miyaura reactions
摘要:
Schiff bases derived from substituted benzaldehydes are effective ligands for palladium(0) in the Suzuki-Miyaura coupling of phenylboronic acid with aryl, benzyl and allyl bromides under mild conditions. (c) 2008 Elsevier Ltd. All rights reserved.
Development of an Asymmetric Trimethylenemethane Cycloaddition Reaction: Application in the Enantioselective Synthesis of Highly Substituted Carbocycles
作者:Barry M. Trost、Steven M. Silverman、James P. Stambuli
DOI:10.1021/ja207550t
日期:2011.12.7
azetidine structures, is discussed. The conditions developed to effect an asymmetric TMM reaction using 2-trimethylsilylmethyl allyl acetate were shown to be tolerant of a wide variety of alkene acceptors, providing the desired methylenecyclopentanes with high levels of enantioselectivity. The donor scope was also explored, and substituted systems were tolerated, including one bearing a nitrile moiety. These
enantioselective nucleophilic 1,2‐additions (ee values up to 97 %) from cheap, easily accessible, and never described before, chiral lithium amido zincates is presented. These multicomponent reactants auto‐assemble when mixing, in a 1:1 ratio, a homoleptic diorganozinc (R2Zn) with a chiral lithium amide (CLA). The latter, obtained after a single reductive amination, plays the role of the chiral inductor and is fully
Synthesis of new chiralcis-3-hydroxyazetidines and their application in diethylzinc addition to aldehydes
作者:Zhanbin Zhang、Min Li、Guofu Zi
DOI:10.1002/chir.20470
日期:2007.11
A new series of chiral cis-3-hydroxyazetidines have been prepared from (R)-1-phenylethylamine. They have excellent catalytic activities and enantiomeric selectivities in asymmetricaddition of diethylzinc to aromatic aldehydes.
An NMR study of a 1 : 1 mixture of a chiral lithium amide (4a) and n-BuLi shows that depending on the solvent employed (Et2O or THF) a mixed aggregate can form in proportions that are directly related to the ees measured during the enantioselective alkylation of o-tolualdehyde by these same species.