Synthesis of α-Amino Acids and Derivatives
A nucleophilic acid-free addition of dicyanomethyl acetate to N-methylaldimines gives α-(N-methyl-N-acetyl)amino acid methyl esters in excellent yield.
H. Nemoto, T. Kawamura, N. Miyoshi, J. Am. Chem. Soc., 2005, 127, 14546-14547.
Bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium(III) (FIrpic) is an effective catalyst of a visible-light photoredox reaction of N,N-dimethylaniline derivatives and aryl isocyanates or aryl isothiocyanates to yield α-amino amides or α-amino thioamides. The reaction involves generation of α-aminoalkyl radicals from tertiary amines, followed by radical addition to the electron-deficient carbon of the isocyanates or isothiocyanates.
H. Zhou, P. Lu, X. Gu, P. Li, Org. Lett., 2013, 15, 5646-4649.
The addition of carbamoyl anions derived from N,N-disubstituted formamides and LDA to N-tert-butyl nitrones provided a direct route to α-(N-hydroxy)amino amides. Derivatization of the products by tert-butyl deprotection or N-deoxygenation was demonstrated.
J. T. Reeves, C. Lorenc, K. Camara, Z. Li, H. Lee, C. A. Busacca, C. H. Senanayake, J. Org. Chem., 2014, 79, 5895-5902.
In the presence of oxygen and a small amount of AIBN as radical initiator, primary amines are oxidatively coupled to imines and tertiary amines are cyanated to α-aminonitriles. These metal-free aerobic oxidative coupling reactions may find applications in a wide range of green oxidation chemistry.
L. Liu, Z. Wang, X. Fu, C.-H. Yan, Org. Lett., 2012, 14, 5692-5695.