[EN] CATALYTICS ASYMMETRIC ACTIVATION OF UNACTIVATED C-H BONDS, AND COMPOUNDS RELATED THERETO<br/>[FR] ACTIVATION CATALYTIQUE ASYMETRIQUE DE LIAISONS C-H INACTIVEES ET COMPOSES ASSOCIES
申请人:UNIV BRANDEIS
公开号:WO2006026053A1
公开(公告)日:2006-03-09
One aspect of the present invention is directed in part to catalytic and stereoselective functionalization of unactivated C-H bonds of simple organic substrates. The compounds and methods provided herein allow one to control the stereochemistry in a C-H activation step, activate substrates containing α-hydrogens next to the directing group, and remove a directing group under mild conditions. One aspect of the present invention relates to a transition-metal-catalyzed method for selective and asymmetric oxidation of carbons located in a β- or Ϝ-position relative to an auxiliary. Another aspect of the invention relates to the enantiomerically-enriched substrates and the enantiomerically-enriched products formed via said method. In certain embodiments, oxazoline and oxazinone directing groups are used. In addition, the Boc protecting group has been identified as a directing group which does not necessitate removal.
Oxazo lines were employed,as cyclic chiral directing groups for stereoselective C-H activation. Oxazoline-directed cleavage of the P-C-H bonds followed by reaction with I, gave a wide range of iodinated products. A large range of functional groups are tolerated. PdI2 was isolated in the reaction and found to be converted to Pd(OAc)(2) upon treatment with a combination Of I-2 and PhI(OAC)(2) in situ to achieve catalytic turnover. Diastereoselective iodination of prochiral C-H bonds were also investigated. (c) 2005 Elsevier Ltd. All rights reserved.