1. Gold-Catalyzed Intramolecular Redox Reaction of N-Sulfonyl Alkynyl Hydroxyl Amines 2. Studies Toward the Synthesis of Meloscine

Abstract

Part I. Gold-Catalyzed Intramolecular Redox of N-Sulfonyl alkynyl hydroxyl amines

Addition of R2N-OH onto alkyne will lead to alpha-amino carbonyl compounds that constitute a fundamental organic building block. We realized this concept in an intramolecular fashion using alkyne tethered N-sulfonyl hydroxylamines. Depending on the alkynyl substituents, the reaction follows two distinct manifolds, namely the formation of 3-pyrrolidinones and nitrones.

Part II. Studies Toward the Synthesis of Meloscine

Meloscine, one of melodinus alkaloids, was first isolated in 1989 from ethyl 2-oxocyclopentaneacetate by Overman and Robertson. This was studied further by Bach’s group that increased enantioselectivity via photochemical cycloaddition using chiral complexing agent. Recently, our group published stereoselective one-pot synthesis of 1- aminoindans and 5,6-fused azacycles using gold-catalyzed Redox-Pinacol-Mannich-Michael cascade. This one-pot protocol prompted us to pursue a consice route to the core structure of meloscine in more efficient and stereoselective way. Using this atom-efficient, step-, and redox-economical protocol, we investigated a way to synthesis meloscine from acetoacetanilide.