One-shot access to α,ß-difunctionalized azepenes and dehydropiperidines by reductive cross-coupling of α-selenonyl-ß-selenyl enamides with organic bromides.

The synthesis of α- and α,ß-functionalized azepenes and dehydropiperidines from readily prepared α-selenonyl eneformamides or enecarbamates has been achieved through Fe-catalyzed α-substitutive deselenonation, ß-regioselective lithiation/trapping, and Co-catalyzed reductive cross-coupling protocols.

Trapping of carbolithiation-derived tertiary benzylic α-lithio piperidines with carbon electrophiles: Controlling the formation of α-amino quaternary and vicinal stereocenters.

The interception of carbolithiation-derived tertiary benzylic α-lithio piperidines with carbon electrophiles, under HMPA-mediated conditions, has led to the diastereoselective synthesis of vicinally functionalized piperidines bearing α-amino quaternary stereocenters.

Direct access to functionalized benzotropones, azepanes, and piperidines by reductive cross-coupling of α-bromo enones with α-bromo enamides.

The synthesis of functionalized azepenes and piperidines bearing an α-cycloheptenone or benzotropone derivative has been accomplished through direct reductive cross-coupling of α-bromo eneformamides or enecarbamates with highly versatile α-bromo benzotropone derivatives, under cobalt catalysis. The coupling products have been further elaborated to other synthetically useful aza-heterocyclic frameworks.

Expedient access to α,ß-difunctionalized azepenes using α-halo eneformamides: application to the one-pot synthesis of 2-benzazepanes.

The regioselective synthesis of α,ß-difunctionalized (alkenyl, aryl, sulfonyl, allyl, or alkynyl) azepenes has been accomplished through α-halo eneformamides. A successful implementation of the vicinal functionalization strategy has led to a one-pot synthesis of 2-benzazepanes whose benzenoid portion is highly functionalized.