摘要:
1-Methyl, 1-(alkoxymethyl) and 1-(trimethylsilylmethyl)benzotriazoles are metallated at the alpha-carbon. Trapping of the resulting metallated species with chlorotrimethylsilane gives compounds which undergo Peterson olefination even with hindered ketones. In some cases, metallation at the 4-position of the benzotriazole is observed. An exhaustive metallation/silylation sequence gives 4-trimethylsilyl substituted 1-benzotriazoles in good yields. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.