Gold-Catalyzed Cyclizations of (o-Alkynyl)phenoxyacrylates with External Nucleophiles: Regio- and Stereoselective Synthesis of Functionalized Benzo[b]oxepines
摘要:
A catalytic approach to benzo[b]oxepines with high stereoselectivity by Au-catalyzed cyclization of (o-alkynyl)phenoxyacrylates with various nucleophiles under mild reaction conditions has been developed. Notably, the use of vinyl ether instead of alcohol could afford the same benzoxepines. The reaction may proceed by Au-catalyzed oligomerization of vinyl ether to release the alcohol, which then reacts with (o-alkynyl)phenoxyacrylates to furnish the benzoxepines.
heterocyclic compounds. We achieved palladium-catalyzed migratory cycloisomerization of 3-o-alkynylphenoxy acrylic acid ester derivatives to give 2,3-disubstitutedbenzofurans. Although there are several reports of benzofuransynthesis with palladium-catalyzed migratory cycloisomerization, migratory groups are limited to allyl and propargyl groups. This report is the first example of benzofuransynthesis with
Regio- and Diastereoselective Construction of Functionalized Benzo[<i>b</i>]oxepines and Benzo[<i>b</i>]azepines via Recyclable Gold(I)-Catalyzed Cyclizations
作者:Siqi Liu、Wenli Hu、Wenyan Hao、Jianhui Xia、Mingzhong Cai
DOI:10.1021/acs.joc.2c00446
日期:2022.6.3
alcohols has been developed by using an MCM-41-anchored diphenylphosphine-Au(I) complex [MCM-41-Ph2P-AuNTf2] as the catalyst under mild reaction conditions, yielding diverse functionalized benzo[b]oxepines or benzo[b]azepines with good to high yields and excellent diastereoselectivity. This heterogenizedgold(I) catalyst exhibits a comparable activity to homogeneous Ph3PAuNTf2 and can be facilely recovered