Stereospecific Synthesis of β3-Amino Acid Derivatives from Propargylic Alcohols: Efficient Solution-Phase Synthesis of Oligopeptides without Coupling Agents

Chemoselective and metal-free reduction of α,β-unsaturated ketones by in situ produced benzeneselenol from O-(tert-butyl) Se-phenyl selenocarbonate

The carbon–carbon double bond of arylidene acetones and chalcones can be selectively reduced with benzeneselenol generated in situ by reacting O-(tert-butyl) Se-phenyl selenocarbonate with hydrochloric acid in ethanol. This mild, metal-free and experimentally simple reduction procedure displays considerable functional-group compatibility, products are obtained in good to excellent yields, and the use of toxic Se/CO mixture and NaSeH, or the smelly and air-sensitive benzeneselenol, is avoided.

The carbon–carbon double bond of arylidene acetones and chalcones can be selectively reduced with benzeneselenol generated in situ by reacting O-(tert-butyl) Se-phenyl selenocarbonate with hydrochloric acid in ethanol.

Metal-Free Synthesis of N-(Carboselenoate) Benzimidazolones by Cascade Cyclization of ortho-Diisocyanoarenes and Selenosulfonates

A facile synthesis of N-(carboselenoate) benzimidazolones through metal-free reactions of ortho-diisocyanoarenes with selenosulfonates is reported here. The desired products are obtained in moderate to good yields with good functional group compatibility. The ortho-diisocyanoarenes are applied to the construction of 2-benzimidazolone derivatives for the first time.

Copper(i)/succinic acid cooperatively catalyzed one-pot synthesis of organoselenium-propargylamines via A3-coupling

Selenium propargylamines were synthesized via an A³-coupling approach using piperidine, p-methoxybenzaldehyde, and trimethylsilyl selenium–acetylene, catalyzed by copper(i) chloride and succinic acid as an additive, in good to excellent yields.

General, Mild, and Metal-Free Synthesis of Phenyl Selenoesters from Anhydrides and Their Use in Peptide Synthesis

A mild, practical, and simple procedure for phenyl selenoesters synthesis from several anhydrides and diphenyl diselenide was developed. This transition-metal-free method provides a straightforward entry to storable Fmoc-amino acid selenoesters which are effective chemoselective acylating reagents. An application to oligopeptide synthesis was illustrated.

Synthesis of Oxazolidin-2-ones by Oxidative Coupling of Isonitriles, Phenyl Vinyl Selenone, and Water

Reaction of alkyl isocyanides, phenyl vinyl selenone, and water in the presence of a catalytic amount of Cs2 CO3 afforded oxazolidin-2-ones in good yields. This unprecedented heteroannulation process created four chemical bonds in a single operation with the isocyano group acting formally as a polarized double bond and phenyl vinyl selenone as a latent 1,3-dipole. The phenylselenonyl group played a triple role as an electron-withdrawing group to activate the 1,4-addition, a leaving group, and a latent oxidant in this transformation.