title: Dirhodium(II)-Catalyzed Annulation of Enoldiazoacetamides with α-Diazoketones: An Efficient and Highly Selective Approach to Fused and Bridged Ring Systems.
abstract: A dirhodium(II)-catalyzed annulation reaction between two structurally different diazocarbonyl compounds furnishes the donor-acceptor cyclopropane-fused benzoxa[3.2.1]octane scaffold with excellent chemo-, regio-, and diastereoselectivity under exceptionally mild conditions. The composite transformation occurs by [3+2]-cycloaddition between donor-acceptor cyclopropenes generated from enoldiazoacetamides and carbonyl ylides formed from intramolecular carbene-carbonyl cyclization in one pot with one catalyst. The annulation products can be readily transformed into benzoxa[3.3.1]nonane and hexahydronaphthofuran derivatives with exact stereocontrol. This method allows the efficient construction of three fused and bridged ring systems, all of which are important skeletons of numerous biologically active natural products.
authors.affiliation: Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA.
authors.forename: Qing-Qing
authors.initials: QQ
authors.lastname: Cheng
authors.affiliation: Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA.
authors.forename: Julietta
authors.initials: J
authors.lastname: Yedoyan
authors.affiliation: Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA.
authors.forename: Hadi
authors.initials: H
authors.lastname: Arman
authors.affiliation: Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA. michael.doyle@utsa.edu.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Doyle
mesh_terms: D000081:Acetamides / Q000138:chemical synthesis / Q000737:chemistry*; D001391:Azo Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D061565:Cycloaddition Reaction; D003521:Cyclopropanes / Q000138:chemical synthesis / Q000737:chemistry*; D005663:Furans / Q000138:chemical synthesis / Q000737:chemistry; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000081:Acetamides; D001391:Azo Compounds; D003521:Cyclopropanes; D005663:Furans; D007659:Ketones; C030797:cyclopropane; D012238:Rhodium
keywords: annulation; cyclopropenes; diazo compounds; rhodium; ylides