Lewis Acid-Mediated Highly Regioselective SN2-Type Ring-Opening of 2-Aryl-N-tosylazetidines and Aziridines by Alcohols
摘要:
Lewis acid-mediated highly regioselective S(N)2-type ring-opening of 2-aryl-N-tosylazetidines with alcohols to afford various 1,3-amino ethers in excellent yields with good enantiomeric excess is described. Similar S(N)2-type ring-opening of chiral 2-phenyl-N-tosylaziridine with various alcohols produces the corresponding nonracemic 1,2-amino ethers in excellent yields and good ee. The mechanism of the ring-opening of aziridines and azetidines via an S(N)2 pathway is supported by the formation of nonracemic amino ethers.
Lewis acid mediated SN2-type nucleophilic ring opening followed by [4+2] cycloaddition of N-tosylazetidines with aldehydes and ketones: synthesis of chiral 1,3-oxazinanes and 1,3-amino alcohols
作者:Manas K. Ghorai、Kalpataru Das、Amit Kumar
DOI:10.1016/j.tetlet.2007.04.097
日期:2007.6
A highly efficient strategy for Cu(OTf)(2) mediated S(N)2-type nucleophilic ring opening followed by [4+2] cycloaddition reactions of enantiopure 2-phenyl-N-tosylazetidines with various aldehydes and ketones afforded a variety of substituted 1,3-oxazinanes and 1,3-amino alcohols in excellent yields, excellent de and good to excellent ee. The proposed S(N)2-type mechanism of the cycloaddition reaction is supported by experimental evidence. (c) 2007 Elsevier Ltd. All rights reserved.