Palladium-Catalyzed Alkylation of 1,4-Dienes by CH Activation
摘要:
Activated: the title reaction proceeds with a broad range of nucleophiles and variously substituted 1,4-dienes under mild conditions, and provides direct access to the corresponding 1,3-diene-containing products with high regio- and stereocontrol (see scheme; 2,6-DMBQ=2,6-dimethylbenzoquinone, EWG=electron-withdrawing group). This is the first catalytic allylic C-H alkylation that proceeds in the absence of sulfoxide ligands.
A Highly Enantio- and Diastereoselective Molybdenum-Catalyzed Asymmetric Allylic Alkylation of Cyanoesters
作者:Barry M. Trost、John R. Miller、Christopher M. Hoffman
DOI:10.1021/ja2029602
日期:2011.6.1
An efficient molybdenum-catalyzedasymmetricallylicalkylation (Mo-AAA) of cyanoester nucleophiles is reported. A number of highly functionalized branched cyanoesters containing a quaternary carbon stereocenter with a vicinal tertiary stereocenter are obtained. This method generates a number of functionalized cyanoesters in excellent yield and chemoselectivity in good to excellent diastereoselectivity
Meeting the challenge: The first asymmetric catalytic C*P bond formation employing electrophilic phosphorus compounds has been developed using a catalytic amount of a dimeric cinchona alkaloid, and a subsequent one‐pot process to deliver high stereoselectivities and good yields of α‐quaternary α‐phosphino β‐amino acids (see scheme). 31P NMR experiments suggest a novel reaction mechanism wherein a
迎接挑战:使用催化量的二聚金鸡纳生物碱和随后的单锅法开发了使用亲电磷化合物形成的首个不对称催化C * P键的形成方法,该方法可实现高立体选择性和良好的α-四价α收率-膦基β-氨基酸(参见方案)。31 P NMR实验表明一种新颖的反应机理,其中金鸡纳生物碱亲核地活化了亲电磷。