Sodium Salts of Anionic Chiral Cobalt(III) Complexes as Catalysts of the Enantioselective Povarov Reaction
作者:Jie Yu、Hua-Jie Jiang、Ya Zhou、Shi-Wei Luo、Liu-Zhu Gong
DOI:10.1002/anie.201504790
日期:2015.9.14
The sodium salts of anionic chiral cobalt(III) complexes (CCC−Na+) have been found to be efficient catalysts of the asymmetric Povarov reaction of easily accessible dienophiles, such as 2,3‐dihydrofuran, ethyl vinyl ether, and an N‐protected 2,3‐dihydropyrrole, with 2‐azadienes. Ring‐fused tetrahydroquinolines with up to three contiguous stereogenic centers were thus obtained in high yields, excellent
[reaction: see text] (R,R)-3-Aza-3-benzyl-1,5-dihydroxy-1,5-diphenylpentane (1) ligated Ti(IV) complex (1-TiCl(2)) is used as a chiral Lewis acid catalyst for promoting asymmetric IED Diels-Alder reaction between electron-rich dienophiles and electron-poor dienes. Here we introduce a facileroute for the synthesis of asymmetric tetrahydroquinoline derivatives using the above-mentioned chiral catalyst
Cycloaddition of N-arylimines with α-methylstyrenesor 2,3-dihydrofuran was efficiently catalyzed by tris(4-bromophenyl)aminiumhexachloroantimonate (Ar3N + ËSbCl6 - ) producing tetrahydroquinolinederivatives in excellent yields. The reaction was controlled sensitivelyby the oxidation potentials of the imine and the dienophile.