title: Synthesis of novel alpha-substituted and alpha,alpha-disubstituted amino acids by rearrangement of ammonium ylides generated from metal carbenoids.
abstract: [reaction: see text] A new and general four-step synthesis of protected alpha-substituted and alpha,alpha-disubstituted amino acids has been developed. The key step involves intramolecular ammonium ylide generation from a copper carbenoid with concomitant [2,3] rearrangement. The aromatic template serves as a tether, protecting group, and activating group for peptide coupling. The ylide rearrangement products can be converted into protected cyclic amino acids by ring-closing metathesis.
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK. j.s.clark@nottingham.ac.uk
authors.forename: J Stephen
authors.initials: JS
authors.lastname: Clark
authors.forename: Mark D
authors.initials: MD
authors.lastname: Middleton
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D000598:Amino Acids, Cyclic / Q000138:chemical synthesis / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry
chemical_list: D000596:Amino Acids; D000598:Amino Acids, Cyclic; D000644:Quaternary Ammonium Compounds; D012428:Ruthenium