NH2 As a Directing Group: From the Cyclopalladation of Amino Esters to the Preparation of Benzolactams by Palladium (II)-Catalyzed Carbonylation of N-Unprotected …
An unusual NH2-directed Pd (II)-catalyzed carbonylation of quaternary aromatic α-amino esters to yield benzolactams has been developed. The steric hindrance around the amino group is pivotal for the success of the process. The stoichiometric cyclometalation of a variety amino esters has been studied in order to evaluate the influence of the different variables (size of the metallacycle, aromatic ring substituents, and steric bulk) in the ...