Solvent‐free cycloaddition reaction of 3‐indolylimines with chloroacetyl chloride under microwave irradiation

Abstract

Solvent-free

Novel Syntheses of Azetidines and Azetidinones

“…If the reaction between an acyl chloride and an aromatic imine is performed in ionic liquids, and in the presence of Yb(OTf) 2 , the addition of a base is not necessary for the reaction to occur, with remarkable selectivity toward the trans adduct . Also, a solvent-free procedure, under microwave irradiation, was described …”

More Sustainable Approaches for the Synthesis of N-Based Heterocycles

“…An example of synthesis of some spiro[azetidine-indole]diones was reported (Scheme ) through the use of basic alumina-supported potassium carbonate. The MWI-induced cycloaddition of 3-arylimino indolinones with chloroacetyl chloride can be performed by irradiating the reactants for a few minutes allowing the formation of spiro β-lactam in good yields (85−92%) …”

“…The MWI-induced cycloaddition of 3-arylimino indolinones with chloroacetyl chloride can be performed by irradiating the reactants for a few minutes allowing the formation of spiro β-lactam in good yields (85-92%). 113 About the β-lactam substituents, an R-amino group can be deprotected from tetrachlorophtaloyl in good yields (83-99%) by reacting it with ethylenediamine at room temperature for 5 min (Scheme 9). 114 In the solvent-free modification of cephalosporin synthesis, the free amino group of the 7-ACA (7-amino-cephalosporanic acid) can be modified to an amide group in excellent yields (83-93%) by reaction with heterocyclic acids under microwave irradiation for a couple of minutes using basic alumina as an inorganic support.…”

Recent Advances in Microwave-Assisted Synthesis of Heterocyclic Compounds

“…The resulting ketene is then captured by an imine, followed by intramolecular closure to provide the desired β-lactam in a convenient one-pot procedure [170][171][172][173][174][175]. Staudinger-type reactions can also utilize a two-step procedure.…”