title: Transition-Metal-Free Cyclopropanation of 2-Aminoacrylates with N-Tosylhydrazones: A General Route to Cyclopropane α-Amino Acid with Contiguous Quaternary Carbon Centers.
abstract: Cyclopropanation of 2-aminoacrylates with N-tosylhydrazones could proceed smoothly under transition-metal-free conditions via a [3 + 2] cycloaddition process. This robust protocol exhibits excellent generality, delivering a wide spectrum of cyclopropane α-amino acid esters bearing contiguous quaternary carbon centers in high yields and diastereoselectivities. With these readily available products, the steric convergence of cyclopropane α-amino acids could be readily obtained.
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, China.
authors.forename: Chuanle
authors.initials: C
authors.lastname: Zhu
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, China.
authors.forename: Jiawei
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, China.
authors.forename: Pengquan
authors.initials: P
authors.lastname: Chen
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, China.
authors.forename: Wanqing
authors.initials: W
authors.lastname: Wu
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, China.
authors.forename: Yanwei
authors.initials: Y
authors.lastname: Ren
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, China.
authors.forename: Huanfeng
authors.initials: H
authors.lastname: Jiang
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D061565:Cycloaddition Reaction; D003521:Cyclopropanes / Q000138:chemical synthesis* / Q000737:chemistry; D006835:Hydrazones / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism; D014105:Tosyl Compounds / Q000737:chemistry*; D028561:Transition Elements
chemical_list: D000596:Amino Acids; D003521:Cyclopropanes; D006835:Hydrazones; D014105:Tosyl Compounds; D028561:Transition Elements; D002244:Carbon