Palladium-Catalyzed Enantioselective 7--Trig Carbopalladation/Carbonylation: Cascade Reactions To Achieve Atropisomeric Dibenzo[,]azepin-6-ones.

Enantioselective 7--trig cyclocarbopalladation-initiated carbonylation cascade reactions, leading to seven-membered dibenzo[,]azepin-6-ones containing a thermodynamically controlled stereogenic axis, have been realized for the first time. A series of 7-acetate- or 7-acetamide-substituted dibenzo[,]azepin-6-ones are obtained under atmospheric pressure of CO in good yields with excellent diastereo- and enantioselectivities. The calculated energy difference between the diastereoisomers generated from the stereogenic biaryl axis and the stereogenic center is approximately 2.8 kcal/mol, which agrees with the excellent diastereoselectivity observed.