Open AccessGram-Scale Domino Synthesis in Batch and Flow Mode of Azetidinium Salts
Author(s) -
Alessandra Sivo,
Vincenzo Ruta,
Gianvito Vilé
Publication year - 2021
Publication title -
journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.2
H-Index - 228
eISSN - 1520-6904
pISSN - 0022-3263
DOI - 10.1021/acs.joc.1c01487
Subject(s) - aminolysis , chemistry , flow chemistry , microreactor , combinatorial chemistry , intramolecular force , amine gas treating , organic synthesis , continuous flow , reductive amination , amination , organic chemistry , biochemical engineering , catalysis , engineering
Azetidinium salts are important motifs in organic synthesis but are difficult to obtain due to extremely long synthetic protocols. Herein, a rapid continuous-flow process for the on-demand synthesis of azetidinium salts is described. In particular, the nucleophilic addition of secondary amines and the subsequent intramolecular N-cyclization have been investigated in batch and continuous-flow modes, exploring the effects of solvent type, temperature, reaction time, and amine substituent on the synthesis of azetidinium salts. This has enabled us to quickly identify optimal reaction conditions and obtain microkinetic parameters, verifying that the use of a flow reactor leads to a reduction of the activation energy for the epichlorohydrin aminolysis due to the better control of mass and heat transfer during reaction. This confirms the key role of continuous-flow technologies to affect the kinetics of a reaction and make synthetic protocols ultrarapid and more efficient.