Highly Enantioselective and Anti-Diastereoselective Catalytic Intermolecular Glyoxylate–Ene Reactions: Effect of the Geometrical Isomers of Alkenes
摘要:
An efficient method for the synthesis of homoallylic alcohols with high enantioselectivities and anti-diastereoselectivities via an In(III)-catalyzed intermolecular glyoxylateene reaction has been developed. The geometrical isomers of alkenes were shown to have different reactivities. Only the isomers of the alkenes having a proton beta-cis to the substituent reacted in this catalytic system.
Access to “Friedel–Crafts-Restricted” <i>tert</i>-Alkyl Aromatics by Activation/Methylation of Tertiary Benzylic Alcohols
作者:Joshua A. Hartsel、Derek T. Craft、Qiao-Hong Chen、Ming Ma、Paul R. Carlier
DOI:10.1021/jo202371c
日期:2012.4.6
Herein we describe a two-step protocol to prepare m-tert-alkylbenzenes. The appropriate tertiary benzylic alcohols are activated with SOCl2 or concentrated HCl and then treated with trimethylaluminum, affording the desired products in 68-97% yields (22 examples). This reaction sequence is successful in the presence of a variety of functional groups, including acid-sensitive and Lewis-basic groups. In addition to t-Bu groups, 1,1-dimethylpropyl and 1-ethyl-1-methylpropyl groups can also be installed using this method.
The Preparation and Polymerization of Some Alkyl Styrenes<sup>1,2</sup>
作者:C. S. Marvel、R. E. Allen、C. G. Overberger
DOI:10.1021/ja01210a051
日期:1946.6
Stereoconvergent Approach to the Enantioselective Construction of α‐Quaternary Alcohols by Radical Epoxide Allylation
Abstract: We describe a highly stereoconvergent radical epoxide allylation towards diastereomerically and enantiomerically enriched α‐quaternary alcohols in two steps from olefins. Our approach combines the stereospecifity and enantioselectivity of the Shi epoxidation with the unprecedented Ti(III)‐promoted intramolecular radical group transfer allylation of epoxides. A directional isomerization step via configurationally labile radical intermediates enables the selective preparation of all carbon quaternary stereocenters in a unique fashion.