title: Hydrodehalogenation of alkyl iodides with base-mediated hydrogenation and catalytic transfer hydrogenation: application to the asymmetric synthesis of N-protected α-methylamines.
abstract: We report a very mild synthesis of N-protected α-methylamines from the corresponding amino acids. Carboxyl groups of amino acids are reduced to iodomethyl groups via hydroxymethyl intermediates. Reductive deiodination to methyl groups is achieved by hydrogenation or catalytic transfer hydrogenation under alkaline conditions. Basic hydrodehalogenation is selective for the iodomethyl group over hydrogenolysis-labile protecting groups, such as benzyloxycarbonyl, benzyl ester, benzyl ether, and 9-fluorenyloxymethyl, thus allowing the conversion of virtually any protected amino acid into the corresponding N-protected α-methylamine.
authors.affiliation: Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center , 1901 East Road, Houston, Texas 77054, United States.
authors.forename: Pijus K
authors.initials: PK
authors.lastname: Mandal
authors.forename: J Sanderson
authors.initials: JS
authors.lastname: Birtwistle
authors.forename: John S
authors.initials: JS
authors.lastname: McMurray
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D002384:Catalysis; D006865:Hydrogenation; D007454:Iodides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008744:Methylamines / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D000468:Alkalies; D007454:Iodides; D008744:Methylamines