Expedient access to substituted 3-amino-2-cyclopentenones by dirhodium-catalyzed [3+2]-annulation of silylated ketene imines and enoldiazoacetates.

In a reaction that proceeds under mild conditions with remarkable functional group tolerance, structurally diverse 3-amino-2-cyclopentenones bearing a quaternary carbon at the 4-position have been synthesized through a formal [3+2]-cycloaddition reaction of silylated ketene imines (SKIs) and enoldiazoaceates by dirhodium catalysis.

Diazoacetoacetate enones for the synthesis of diverse natural product-like scaffolds.

Diazoacetoacetate enones are a new class of Michael acceptors that enable the efficient construction of natural product-like scaffolds. Through their Michael addition reactions, including those with silyl enol ethers, indoles, pyrroles, and amines, δ-functionalized diazoacetoacetates are formed in high yield and with overall operational efficiency. Subsequent catalytic dinitrogen extrusion reactions provide access to a diverse series of natural product-like carbo- and heterocyclic ring systems in only three steps from commercial materials.