The titanium-catalysed epoxidation of homoallylic α-amino alcohols
摘要:
Diastereoselective titanium-catalysed epoxidation reactions of acyclic homoallylic alcohols are presented. The results are compared to the stereochemical outcome obtained by the application of the commonly used vanadium catalyst, VO(acac)(2). The key role of the syn-bis-homoallylic carbamate group in obtaining high yields and reversed diastereoselectivities in the titanium-catalysed reactions is discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.
Dramatic changes in diastereoselectivity with the quantity of titanium tetrachloride used in Lewis acid mediated reactions of allylsilane with .alpha.-amino aldehydes