Synthesis of Functionalized Biaryls Based on a Heck Cross-Coupling-[3+3] Cyclization Strategy
作者:Peter Langer、Gerson Mroß、Helmut Reinke
DOI:10.1055/s-2008-1072654
日期:——
6-Arylsalicylates were regioselectively prepared by formal [3+3] cyclization of 1,3-bis(silyloxy)-1,3-butadienes with 1-aryl-3-ethoxyprop-2-en-1-ones which are available by Heck reaction of benzoyl chlorides with ethylvinyl ether. In this context, the first [3+3] cyclizations of brominated substrates are reported.
The formal [3+3] cyclization of 1,3-bis(silyloxy)buta-1,3-dienes with 1-aryl-3-ethoxyprop-2-en-1-ones, available by Heck reaction of benzoyl chlorides with ethyl vinyl ether, afforded a variety of 6-arylsalicylates. The reaction of the products with concentrated sulfuric acid resulted in the formation of fluorenones. 6-Alkylsalicylates were prepared by cyclization of 1,3-bis(silyloxy)buta-1,3-dienes