Chiral γ‐Lactams by Enantioselective Palladium(0)‐Catalyzed Cyclopropane Functionalizations. (12th August 2015)

• Record Type: Journal Article
• Authors: Pedroni, Julia; Cramer, Nicolai
• Is Part Of: Angewandte Chemie. Volume 127:Number 40(2015)
• Page Start: 11992
• Page End: 11995
• Publication Date: 2015-08-12
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201505916
• Languages: English
• ISSNs: 0044-8249

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Cyclopropanes fused to pyrrolidines are important structural features found in a number of marketed drugs and development candidates. Typically, their synthesis involves the cyclopropanation of a dihydropyrrole precursor. Reported herein is a complementary approach which employs a palladium(0)‐catalyzed CH functionalization of an achiral cyclopropane to close the pyrrolidine ring in an enantioselective manner. In contrast to aryl–aryl couplings, palladium(0)‐catalyzed CH functionalizations involving the formation of C(sp³)C(sp³) bonds of saturated heterocycles are very scarce. The presented strategy yields cyclopropane‐fused γ‐lactams from chloroacetamide substrates. A bulky Taddol phosphonite ligand in combination with adamantane‐1‐carboxylic acid as a cocatalyst provides the γ‐lactams in excellent yields and enantioselectivities.</p> </abstract>