Lewis acid promoted highly diastereoselective desymmetric intramolecular cyclization of allylstannane with a diketone
摘要:
The Lewis acid mediated desymmetric intramolecular cyclization of prochiral allylstannyl diketone 1 gave a mixture of two diastereomers 2 and 3. Highly diastereoselective synthesis of each diastereoisomer was accomplished by proper choice of the Lewis acids. (C) 1997 Elsevier Science Ltd. All rights reserved.
Hydrocarbon Oxidation vs C−C Bond-Forming Approaches for Efficient Syntheses of Oxygenated Molecules
作者:Kenneth J. Fraunhoffer、Daniel A. Bachovchin、M. Christina White
DOI:10.1021/ol047800p
日期:2005.1.1
[Reaction: see text] A hydrocarbon oxidation approach has been applied to the construction of several linear (E)-allylic alcohols that have served as intermediates in the synthesis of natural products and natural product-like molecules. In the original syntheses, these intermediates were constructed using a standard Wittig-type olefination approach. We report here that routes to these same intermediates
[EN] CATALYTIC SULFOXIDE-PROMOTED C-H OXIDATION, AND REGIOSELECTIVE PREPARATION OF ALLYLIC CARBOXYLATES<br/>[FR] OXYDATION C-H CATALYTIQUE PAR SULFOXYDE ET PREPARATION REGIOSELECTIVE DE CARBOXYLATES ALLYLIQUES
申请人:HARVARD COLLEGE
公开号:WO2005062811A2
公开(公告)日:2005-07-14
One aspect of the present invention relates to a method of preparing allylic carboxylate compounds comprising the step of contacting a compound comprising an allylic hydrogen atom with a carboxylic acid in the presence of palladium, a sulfoxide compound, and an oxidant. For example, the instant invention provides a catalytic method for the direct C-H oxidation of monosubstituted olefins to prepare linear (E)-allylic acetates in high regio- and stereoselectivities. In addition, the method of the instant invention can be used to prepare branched allylic carboxylates with high yield and regioselectivity. Another aspect of the present invention relates to sulfoxide compounds that are useful as catalysts to effect C-H oxidation. Remarkably, the allylic oxidation method of the invention is compatible with a wide range of functionality, such as amides, carbamates, carbonates, esters, and ethers.