New Chiral Oxazoline-Phosphite Ligands for the Enantioselective Copper-Catalyzed 1,4-Addition of Organozinc Reagents to Enones
作者:Iris H Escher、Andreas Pfaltz
DOI:10.1016/s0040-4020(00)00143-5
日期:2000.4
A series of new P,N-ligands with a binaphthyl and an oxazoline moiety were prepared, which are efficient ligands for the enantioselectivecopper-catalyzed 1,4-addition of organozinc reagents to enones. Increasing the steric bulk in the 3,3′-position of binaphthyl from an H to a biphenylyl moiety improved the ee from 65 to 94% in the reaction of diethylzinc with cyclopentenone.
Abstract A new class of 3,3′-disubstituted chiral (R)-BINOL-derived phosphoric acid derivatives has been prepared. The synthetic method has been optimized by involving Pd/C as a catalyst in the Suzuki–Miyaura cross coupling using a non-protected BINOL derivative. The target compounds have been characterized and tested for their α-glucosidase inhibitory and antibacterial activities.
Asymmetric Allylboration of Aldehydes and Ketones Using 3,3‘-Disubstitutedbinaphthol-Modified Boronates
作者:T. Robert Wu、Lixin Shen、J. Michael Chong
DOI:10.1021/ol0490882
日期:2004.8.1
Allylboronates derived from 3,3'-disubstituted 2,2'-binaphthols react with aldehydes and ketones to give the expected allylated products with up to >99:1 er. Highest selectivities were observed for aromatic ketones. The bis(trifluoromethyl) derivative is particularly outstanding in terms of reactivity, selectivity, and robustness.