1‐Alkoxyamino‐2‐nitroalkanes as Key Building Blocks for a Chemo‐ and Diastereoselective Synthesis of a New Type of Polyfunctionalized N‐Alkoxypiperidine

Abstract

A highly efficient conversion of β-nitrostyrenes into a new kind of functionalized N-alkoxy-2-hydroxypiperidine in two steps was developed, giving excellent yields and diastereoselectivity. The prepared compounds are the first examples of N-alkoxy-2-hydroxypiperidines. The synthetic approach involved the conjugate addition of alkoxyamines to β-nitrostyrenes, followed by Michael addition of the isolated nitro-

Solvent-Free Henry and Michael Reactions with Nitroalkanes Promoted by Potassium Carbonate as a Versatile Heterogeneous Catalyst

“…On this purpose potassium carbonate [18,19] was identified as a suitable catalyst and produced average to good results for the nitroaldol reaction (Table 3) and good to excellent results for the Michael addition (Table 4). To the best of our knowledge, potassium carbonate was previously reported to catalyse only a few examples of Michael addition reactions, although never under neat conditions but with the required assistance of solvents [20,21], ultrasounds activation, and ionic liquids [22], or with the use of a limited number of substrates as starting materials [23] or else not involving nitroalkanes but different nucleophiles [24][25][26].…”