title: Asymmetric Radical Cyclopropanation of Alkenes with In Situ-Generated Donor-Substituted Diazo Reagents via Co(II)-Based Metalloradical Catalysis.
abstract: Donor-substituted diazo reagents, generated in situ from sulfonyl hydrazones in the presence of base, can serve as suitable radical precursors for Co(II)-based metalloradical catalysis (MRC). The cobalt(II) complex of D2-symmetric chiral porphyrin [Co(3,5-DitBu-Xu(2'-Naph)Phyrin)] is an efficient metalloradical catalyst that is capable of activating different N-arylsulfonyl hydrazones for asymmetric radical cyclopropanation of a broad range of alkenes, affording the corresponding cyclopropanes in high yields with effective control of both diastereo- and enantioselectivity. This Co(II)-based metalloradical system represents the first catalytic protocol that can effectively utilize donor-type diazo reagents for asymmetric olefin cyclopropanation.
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States.
authors.forename: Xin
authors.initials: X
authors.lastname: Wen
authors.affiliation: Department of Chemistry, University of South Florida , Tampa, Florida 33620, United States.
authors.forename: Xin
authors.initials: X
authors.lastname: Cui
authors.affiliation: Department of Chemistry, University of South Florida , Tampa, Florida 33620, United States.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Wojtas
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States.|Department of Chemistry, University of South Florida , Tampa, Florida 33620, United States.
authors.forename: X Peter
authors.initials: XP
authors.lastname: Zhang
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D003521:Cyclopropanes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure
chemical_list: D000475:Alkenes; D001391:Azo Compounds; D056831:Coordination Complexes; D003521:Cyclopropanes; D003035:Cobalt