Novel and facile generation of azomethine imines from alpha-silylnitrosamines and subsequent cycloaddition with dipolarophiles leading to a variety of pyrazole derivatives have been developed. The key to the reaction is a 1,4-silatropic shift caused by strong affinity of the nitroso oxygen atom toward the silicon atom. Thus, alpha-silylnitrosamines are treated with 1 equiv. of dipolarophiles in refluxing toluene for 1 h to give pyrazole derivatives in good to excellent yields. (C) 1999 Elsevier Science Ltd. All rights reserved.
FLIEGE, W.;GRASHEY, R.;HUISGEN, R., CHEM. BER., 1984, 117, N 3, 1194-1214
作者:FLIEGE, W.、GRASHEY, R.、HUISGEN, R.
DOI:——
日期:——
KOBAYASHI, YOSHIRO;YAMASHITA, TOSHINORI;TAKAHASHI, KATSUHIRO;KURODA, HISA+, CHEM. AND PHARM. BULL., 1984, 32, N 11, 4402-4409