A new methodology is developed for the efficient synthesis of 1,3-diketone-linked N-substituted pyrroles, pyrrolo[1,2-a]pyrazines, pyrrolo[1,4]diazepines, and pyrrolo [1,4]diazocines in good yields via a Yb(OTf) 3 -catalyzed, nitromethane-mediated reaction of primary amine/diamine, furfural, and 1,3-diketone. Possible mechanisms for these multicomponent reactions are also proposed.

A simple protocol for the protection of amines was realized through a base-catalyzed one-pot reaction of dimedone, β-nitroalkene, and amine. Employing this strategy, a variety of amines/amino acids were protected in excellent yields. These acid/ base stable protected amines can be deprotected by either ethylene diamine or hydrazine hydrate under mild conditions. The practical application of this orthogonal protecting group was demonstrated by the synthesis of cyclic peptide melanotan II via SPPS.

An efficient protocol for the construction of structurally diverse 2-pyridone derivatives from imines and α,β-unsaturated acid chlorides in a single operation is reported.

3,4-Dihydropyridones and 2-piperidinones were efficiently synthesized by boric acid-catalyzed Michael addition of enaminones to electron-deficient α-substituted cinnamic acids and coumarin 3-carboxylic acids, respectively.

The major and minor products for photocyclization of coumarinoyl enamides were identified. The controlled and intermediate-trapping experiments indicate that the formation of the minor isomer involved a stepwise, radical [2+2+2]...