Racemic Vinylallenes in Catalytic Enantioselective Multicomponent Processes: Rapid Generation of Complexity through 1, 6‐Conjugate Additions. Issue 9 (6th February 2019)

• Record Type: Journal Article
• Authors: Huang, Youming; Torker, Sebastian; Li, Xinghan; del Pozo, Juan; Hoveyda, Amir H.
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 9(2019)
• Page Start: 2685
• Page End: 2691
• Publication Date: 2019-02-06
• Subjects: 1, 6-conjugate additions -- boron -- copper -- enantioselective catalysis -- vinylallenes; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201812535
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Racemic vinylallenes are shown to be effective substrates for catalytic multicomponent diastereo‐ and enantioselective 1, 6‐conjugate addition of multifunctional allyl moieties to easily accessible α, β, γ, δ‐unsaturated diesters. Reactions may be catalyzed by 5.0 mol % of a readily accessible NHC‐Cu complex at ambient temperature, and other than a vinylallene, involve B2 (pin)2 and an α, β, γ, δ‐unsaturated diester. A variety of vinylallenes were converted to products bearing a Z‐trisubstituted alkenyl‐B(pin) moiety, a vinyl group, a β, γ‐unsaturated diester unit, and vicinal stereogenic centers in up to 67 % yield, 87:13 Z / E ratio, >98:2 d.r., and 98:2 e.r. Chemoselective modifications involving the alkenyl‐B(pin), the vinyl, or the 1, 2‐disubstituted olefin moieties were carried out to demonstrate versatility and utility. Stereochemical models, based on mechanistic and DFT studies, demonstrate the dynamic behavior of intermediated Cu‐allyl species and account for various selectivity profiles. Abstract : No longer ignored : Readily accessible racemic vinylallenes are shown to be attractive substrates for catalytic multicomponent diastereo‐, and enantioselective 1, 6‐conjugate additions. In just one step, highly complex structures containing a Z ‐trisubstituted alkenyl‐B(pin) moiety, a vinyl group, a β, γ‐unsaturated diester unit, and vicinal stereogenic centers are generated in up to 67 % yield, 87:13 Z / E selectivity, >98:2 d.r., and 98:2 e.r.