Preparation of a Highly Congested Carbazoyl-Derived P,N-Type Phosphine Ligand for Acetone Monoarylations
作者:Wai Chung Fu、Zhongyuan Zhou、Fuk Yee Kwong
DOI:10.1021/acs.organomet.6b00154
日期:2016.5.23
We report a newly developed carbazoyl-derived P,N-type phosphine ligand (L1) for the monoarylation of acetone with aryl chlorides. The proposed Pd(dba)(2)/L1 catalyst exhibited remarkable catalytic reactivity toward highly electron rich and sterically congested aryl chlorides, with catalyst loading as low as 0.1 mol % of Pd along with excellent chemoselectivity. A reaction rate study of the system using electronically diverse aryl chlorides determined the mechanisms regarding the rate-limiting steps in this reaction. The oxidative addition adduct of Pd-PhenCar-Phos with p-chlorotoluene showed the participation of N-Pd coordination in the metal complex. The isolated palladium complex C1 could be utilized as a precatalyst in the transformation and achieved performance comparable to that of the in situ generated palladium species.
Bunnett,J.F.; Sundberg,J.E., Chemical and pharmaceutical bulletin, 1975, vol. 23, p. 2620 - 2628