Structural influences on the oxidation of a series of 2-benzothiazoline analogs
摘要:
We have examined the molecular and electronic structures of a number of benzothiazoline (Bt) and benzothiazole (oBt) analogs that possess phenyl and heterocycle substituents at the 2-position and discuss the ground-state factors that influence the relative rates at which these benzothiazolines are oxidized to benzothiazoles. Our studies indicate that the substituent at the 2-position in the benzothiazoline plays a fundamental role in governing the susceptibility of the species to oxidize. Our calculations for this series of compounds suggest that benzothiazolines that possess a heterocyclic R group oxidize faster than those with a phenyl group. The establishment of a favorable electrostatic interaction between the heteroatoms of the R and Bt/oBt fragments is a primary influence on this reaction while the establishment of it conjugation across the C-R-C-oBt bond is a minor effect. (C) 2011 Elsevier B.V. All rights reserved.
The metal-free reduction of nitroarenes to aniline derivatives was accomplished in a short time by using a benzothiazoline as the hydrogen donor in combination with a Bronsted acid. An enantioselective synthesis of 2-arylquinolines was achieved by using 1-aryl-3-(2-nitrophenyl)propan-1-ones as starting materials and a combination of a benzothiazoline and a chiral phosphoric acid.