Organocatalytic asymmetric addition of thioglycolates to o-quinone methides: a route to 5-substituted-5H-benzoxathiepine-2(3H)-ones. Issue 15 (1st April 2020)

• Record Type: Journal Article
• Authors: Gharui, Chandan; Prakash, Satya; Chopra, Deepak; Pan, Subhas Chandra
• Is Part Of: Organic & biomolecular chemistry. Volume 18:Issue 15(2020)
• Page Start: 2828
• Page End: 2833
• Publication Date: 2020-04-01
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/d0ob00568a
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : The first enantioselective synthesis of 5-substituted-5 H -benzoxathiepine-2(3 H )-ones via organocatalytic asymmetric addition of thioglycolates to o -quinone methides followed by cyclization. Abstract : Herein we have developed the first enantioselective synthesis of 5-substituted-5 H -benzoxathiepine-2(3 H )-ones. 2-Sulfonylmethyl phenols and thioglycolates were employed as reaction partners in this method. The desired thia Michael products were obtained via bifunctional squaramide catalyzed conjugate addition reaction to in situ generated o -quinone methides and then basic hydrolysis followed by cyclization led to the formation of 5-substituted-5 H -benzoxathiepine-2(3 H )-ones. Broad scope and moderate to high enantioselectivities were observed for both products.