Enantioselective Desymmetrization of 3-Substituted Oxetanes: An Efficient Access to Chiral 3,4-Dihydro-2<i>H</i>-1,4-benzoxazines
Viraj A. Bhosale, Martin Nigríni, Martin Dračínský, Ivana Cı́sařová, Ján Veselý
Abstract
Herein, we describe a versatile transition metal/oxidant free synthesis of the chiral 2H-1,4-benzoxazines through chiral phosphoric acid (CPA) catalyzed enantioselective desymmetrization of prochiral oxetanes (30 examples) in up to 99% yield and 99% enantioselectivity under mild reaction conditions. The reported strategy not only complements the conventional 2H-1,4-benzoxazine synthetic strategies but also provides access to key intermediates of therapeutic candidates, i.e., prostaglandin D2 receptor antagonist and M1 positive allosteric modulator (PAM) compound VU0486846.
Topics & Concepts
DesymmetrizationChemistryEnantioselective synthesisYield (engineering)Combinatorial chemistryStereochemistryCatalysisOrganic chemistryMaterials scienceMetallurgyPhenothiazines and Benzothiazines Synthesis and ActivitiesChemical synthesis and alkaloidsCatalytic C–H Functionalization Methods