jo5b02276_si_002.cif (26.1 kB)
Substrate Controlled Synthesis of Benzisoxazole and Benzisothiazole Derivatives via PhI(OAc)2‑Mediated Oxidation Followed by Intramolecular Oxidative O–N/S–N Bond Formation
dataset
posted on 2015-12-18, 00:00 authored by Devireddy Anand, Om P. S. Patel, Rahul K. Maurya, Ruchir Kant, Prem P. YadavA phenyliodine(III) diacetate (PIDA)-mediated,
highly efficient
and tandem approach for the synthesis of aryldiazenylisoxazolo(isothiazolo)arenes
from simple 2-amino-N′-arylbenzohydrazides
has been developed. The reaction proceeds via formation of (E)-(2-aminoaryl)(aryldiazenyl)methanone as the
key intermediate, followed by intramolecular oxidative O–N/S–N
bond formation in one pot at room temperature. The quiet different
reactivity of the substrate is due to the formation of a diazo intermediate
which encounters a nucleophilic attack by carbonyl oxygen on the electrophilic
amine to produce isoxazole products, as compared to the previous reports,, in which an N-acylnitrenium ion intermediate is intramolecularly trapped by an
amine group.