One-Pot Synthesis of Substituted Δ1-Pyrrolines through the Michael Addition of Nitroalkanes to Chalcones and Subsequent Reductive Cyclization in Aqueous Media
AbstractA facile and efficient one-pot synthesis of polysubstituted benzenes was achieved via the Michael addition of malononitrile with α,β-unsaturated imines and a sequential tandem reaction. This reaction generates polysubstituted 2,6-dicyanoanilines in high yields (15 examples, isolated yields of 57-91 %), and proceeds under mild reaction conditions (60°C, 10 min). In addition, a possible mechanism accounting for the reaction is proposed.
A high-yielding cyclocondensation of 4-hydroxycoumarin, phenylglyoxal monohydrate, and heteroarylamines proceeds without catalysis, which gives novel functionalized furo[3,2-c]coumarins and heteroarylamino alkylation of coumarin products in acetonitrile under reflux, is reported for the first time. This tandem process involves sequentially an aldol condensation, Michael addition, a ring closure, and dehydration reaction.
A convenient method for synthesizing 3-amino-1,5-benzodiazepine-2-one via the Michael addition reaction of o-phenylenediamine with dehydroalanine ester derivatives, followed by cyclization, was developed. This simple method was used to obtain a variety of N-substituted 3-amino-1,5-benzodiazepine-2-ones in one pot with good yields.
Ultrasound-promoted, rapid, green, one-pot synthesis of 2′-aminobenzothiazolomethylnaphthols via a multi-component reaction, catalyzed by heteropolyacid in aqueous media