Organocatalytic Enantioselective Diels-Alder Reaction of 2-Trifluoroacetamido-1,3-dienes with α,β-Unsaturated Ketones.
Angew Chem Int Ed Engl 2023;
62:e202214925. [PMID:
36347807 DOI:
10.1002/anie.202214925]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Indexed: 11/11/2022]
Abstract
We report herein the first examples of chiral phosphoric acid-catalyzed enantioselective Diels-Alder reactions between 2-trifluoroacetamido-1,3-dienes 1 and α,β-unsaturated carbonyl compounds 2. Polysubstituted 1-acetamido cyclohexenes 3 were formed in high yields with excellent diastereo- and enantioselectivities. The reaction proceeds through a stepwise process as shown by deuterium labelling experiments. A catalytic enantioselective three-component reaction of 1, 2 and ortho-hydroxybenzhydryl alcohols 4 was subsequently developed furnishing the densely functionalized hexahydroxanthenes 5 in a highly stereoselective manner. This multicomponent reaction generates four chemical bonds with concurrent creation of five contiguous stereocenters.
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