Synthesis of conjugated enynes by assembly of three components, ketones, chloromethyl p-tolyl sulfoxide, and acetylenes, with the magnesium carbenoid 1,2-CC insertion as the key reaction
作者:Hideki Saitoh、Naoyuki Ishida、Tsuyoshi Satoh
DOI:10.1016/j.tetlet.2009.11.082
日期:2010.1
The reaction of 1-chlorovinyl p-tolyl sulfoxides, which were derived from ketones and chloromethyl p-tolyl sulfoxide, with lithium acetylides gave adducts in moderate to good yields. Treatment of the adducts with Grignard reagents resulted in the formation of magnesium carbenoids by the sulfoxide-magnesium exchange reaction. 1,2-Carbon-carbon insertion (1,2-CC insertion) reaction of the generated magnesium carbenoids took place to afford conjugated enynes in good to high yields. This procedure provides a good method for the synthesis of multi-substituted conjugated enynes. (C) 2009 Elsevier Ltd. All rights reserved.
Synthesis of conjugated enynes from ketones and aldehydes by 1,2-CC insertion and 1,2-CH insertion of carbenoids as the key reactions
On the other hand, the addition reactions of 1-chlorovinyl p-tolyl sulfoxides derived from aldehydes with lithium acetylides directly gave conjugated enynes bearing a p-tolyl sulfinyl group at the 1-position through the 1,2-carbon–hydrogen insertion (1,2-CH insertion) reaction of the generated lithium carbenoid intermediates. These procedures provide a good way for the synthesis of multi-substituted