Copper/Chiral Phosphoric-Acid-Catalyzed Intramolecular Reductive Isocyanide-Alkene (1 + 2) Cycloaddition: Enantioselective Construction of 2-Azabicyclo[3.1.0]hexanes.

Enantioenriched 2-azabicyclo[3.1.0]hexanes are accessed from readily available allyl substituted α-isocyanoesters by intramolecular (1 + 2) cycloaddition with the olefinic moiety and isocyano carbon as the respective C2 and C1 units. Cyclopropanation is initiated by 1,1-hydrocupration of isocyanide followed by formimidoylcopper to copper α-aminocarbenoid equilibration and subsequent (1 + 2) cycloaddition. The unprecedented copper/chiral phosphoric acid (CPA) catalytic system can be operated in the presence of water under air, delivering a variety of 2-azabicyclo[3.1.0]hexanes containing an angular all-carbon quaternary stereocenter in good to excellent yields and enantioselectivity.

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

Enantioselective 7-exo-trig cyclocarbopalladation-initiated carbonylation cascade reactions, leading to seven-membered dibenzo[b,d]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[b,d]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.