Enantio- and Diastereoselective Oxidation of N-Alkylimines Using Chiral α-Bromonitriles and Hydrogen Peroxide System

Efficacious One-pot Synthesis of 2-thiazolines and 2-oxazolines Under Solvent and Metal-Free Conditions

Background:

2-oxazolines and 2-thiazolines are important heterocycles due to their extensive applications in chemistry, biochemistry, and pharmacology. Most of the precedent methods for preparing these heterocycles involve one or more drawbacks, including harsh reaction conditions, long reaction times, low yields of products, high temperature, and toxic solvents.

Objective:

The aim of this study was to develop a new and eco-efficient method for the preparation of 2-oxazolines and 2-thiazolines.

Methods:

Amino alcohols were condensed with nitriles in a sealed tube under solvent-free and metal- free conditions.

Results:

Our procedure appears to be highly eco-efficient and promotes quantitative access to 2-oxazolines and 2-thiazolines using simple and minimum manipulation.

Conclusion:

This simple approach allows high conversion for different nitriles yielded from 78 to 99% and easy isolation of the targeted products without further purification. To the best of our knowledge, our procedure is the most efficient and fast method reported to date in terms of chemical yields, number of steps, and atom economy.

An Efficient Microwave Method for the Synthesis of Imines

A large variety of aryl and heterocyclic chiral and achiral imines can be generated simply, efficiently, and cleanly through the use of microwave irradiation and the use of a small amount of molecular sieve. Reactions are rapid and complete in a matter of minutes, and can be quantitative, reducing significantly the time and amount of solvents used in compound isolation and purification.

Catalytic asymmetric oxidation of N-sulfonyl imines with hydrogen peroxide-trichloroacetonitrile system

An efficient and highly enantioselective Payne-type oxidation of N-sulfonyl imines is developed. The reaction exhibits broad substrate generality and unique chemoselectivity based on the combined use of hydrogen peroxide and trichloroacetonitrile under the catalysis of P-spiro chiral triaminoiminophosphorane.