90795-87-2Relevant academic research and scientific papers
Intensified Continuous Flow Michaelis-Arbuzov Rearrangement toward Alkyl Phosphonates
Monbaliu, Jean-Christophe M.,Toupy, Thomas
supporting information, p. 467 - 478 (2022/02/25)
Herein is described the development of an intensified continuous flow process for the preparation of a library of alkyl phosphonates through a Michaelis-Arbuzov rearrangement. A careful process optimization and thorough analysis of the competitive reactions led to a very attractive protocol with unprecedented productivities (up to 4.97 kg of material per day) and a low environmental footprint with the absence of solvent, additives, catalysts, and waste. In-line low-field 31P NMR monitoring was conveniently implemented for rapid optimization and process monitoring. Two key alkyl phosphonate intermediates were also assessed for the unprecedented diazene dicarboxylate-mediated electrophilic amination under continuous flow conditions toward the α-aminophosphonic acid derivatives of Pphenylalanine and Palanine, bioisosters of the natural amino acids phenylalanine and alanine, respectively.
