Efficient Suzuki Coupling of Aryl Chlorides Catalyzed by Palladium(0) with a P,N Heteroligand and Isolation of Unsaturated Intermediates

A mixture of Pd 2 (dba) 3 /[η-C 5 H 4 CH N(C 6 H 5 )]Fe[η - C 5 H 4 P( t -Bu) 2 ] ( 1 ) efficiently catalyzes the Suzuki cross-couplings of a range of arylboronic acids and aryl chlorides, affording the desired biaryl products in high isolated yields. Two catalytically active Pd(0) intermediates, viz. 16-electron [η-C 5 H 4 CH N(C 6 H 5 )]Fe[η-C 5 H 4 P( t -Bu) 2 ]Pd(dba) ( 2 ) and 14-electron linear Pd{[η-C 5 H 4 CH N(C 6 H 5 )]Fe[η-C 5 H 4 P( t -Bu) 2 ]} 2 ( 3 ) together with an oxidative addition product are isolated and crystallographically established.