Tris(oxazoline)/copper-catalyzed coupling of alkynes with nitrones: a highly enantioselective access to β-lactams
摘要:
Chiral tris(oxazoline)/Cu(I) complexes are demonstrated as a type of efficient catalysts for the asymmetric Kinugasa reaction of terminal alkynes with C-arylnitrones, providing a highly enantio- and diastereoselective access to optically active beta-lactams. (C) 2012 Elsevier Ltd. All rights reserved.
Highly Enantioselective Synthesis of Multifunctionalized Dihydrofurans by Copper-Catalyzed Asymmetric [4 + 1] Cycloadditions of α-Benzylidene-β-ketoester with Diazo Compound
摘要:
Highly efficient synthesis of chiral tetrasubstituted 2,3-dihydrofuran derivatives has been realized by Cu-catalyzed asymmetric [4 + 1] cycloadditions of alpha-benzylidene-beta-ketoester with a diazo compound. Following this methodology, a series of optically active multifunctionalized dihydrofurans were prepared in high yield with up to 96% ee and 99/1 dr.