Synthesis of 2,3,5-trisubstituted furans from α-formylaroylketene dithioacetals
摘要:
A new strategy for the synthesis of 2,3,5-trisbustituted furans from alpha-formylketene dithioacetals is described. The protocol involves a facile conversion of alpha-formylketene dithioacetals to vinylketene dithioacetals via Wittig reaction and subsequent N-bromosuccinimide-mediated cyclization to 2,3,5-trisbustituted furans. Further conversion of the 2-thioalkylfurans thus obtained to 2-aminofurans shows the potential synthetic utility of this new approach. (c) 2011 Elsevier Ltd. All rights reserved.
Synthesis of 2,3,5-trisubstituted furans from α-formylaroylketene dithioacetals
摘要:
A new strategy for the synthesis of 2,3,5-trisbustituted furans from alpha-formylketene dithioacetals is described. The protocol involves a facile conversion of alpha-formylketene dithioacetals to vinylketene dithioacetals via Wittig reaction and subsequent N-bromosuccinimide-mediated cyclization to 2,3,5-trisbustituted furans. Further conversion of the 2-thioalkylfurans thus obtained to 2-aminofurans shows the potential synthetic utility of this new approach. (c) 2011 Elsevier Ltd. All rights reserved.
Synthesis of Densely Substituted 1,3-Butadienes through Acid-Catalyzed Alkenylations of α-Oxoketene Dithioacetals with Aldehydes
作者:Changhui Liu、Yanlong Gu
DOI:10.1021/jo5017234
日期:2014.10.17
Aldehydes were proved to be viable reagents for implementing alkenylation of α-oxoketenedithioacetals. AlCl3 was found to be the best catalyst. The established reaction opened an avenue to access densely substituted 1,3-butadiene derivatives. The obtained product bears multiple reactive sites that can be converted into various valuable molecules.
Functionalized 1,3-dienes were efficiently accessed from visible-light-driven, palladium-catalyzed Heck reaction of S,S-functionalized internal vinyl bromides with styrenes under mild conditions. This Heck reaction showcased tolerance of a wide array of functional groups, afforded the target products in moderate to excellent yields through a radical reaction pathway. The resultant diene products could