A Highly Efficient Palladacycle Catalyst for Hydrophenylation of C-, N-, and O-Substituted Bicyclic Alkenes under Aerobic Condition
摘要:
A new phosphine-free palladacycle catalyst 4 was prepared from benzyl oxazoline in high yield and fully characterized. With it as catalyst, hydrophenylation reactions of a wide range of bicyclic alkenes, not only norbornene and norbornadiene but also oxa- and aza-bicyclic alkenes, with iodobenzene proceeded smoothly under aerobic condition without exclusion of water. Up to 1.7 x 10(6) TON as well as 1.2 x 10(5) TOF were achieved.
synthesized. The Pd-complexes of these ligands show high catalytic activity and enantioselectivity in catalyzing the asymmetricHeckreaction. A dramatic switch in enantioselectivity is realized usingligands with and without substituents at the benzylic position of the ligand. Ligands 1 with H as the substituents offer products in (R)-configuration while ligands 2 with the methyl as substituents result
A Highly Efficient Palladacycle Catalyst for Hydrophenylation of C-, N-, and O-Substituted Bicyclic Alkenes under Aerobic Condition
作者:Ke Yuan、Ting Ke Zhang、Xue Long Hou
DOI:10.1021/jo050491b
日期:2005.7.1
A new phosphine-free palladacycle catalyst 4 was prepared from benzyl oxazoline in high yield and fully characterized. With it as catalyst, hydrophenylation reactions of a wide range of bicyclic alkenes, not only norbornene and norbornadiene but also oxa- and aza-bicyclic alkenes, with iodobenzene proceeded smoothly under aerobic condition without exclusion of water. Up to 1.7 x 10(6) TON as well as 1.2 x 10(5) TOF were achieved.