On the selective N-methylation of BOC-protected amino acids.
The selective N-methylation of BOC-protected valine 1a with MeI and NaH in THF (i.e., in the presence of a free carboxyl group) has been attributed to the protection of the carboxylate by chelation to Na(+). An alternative mechanism, involving the formation of the carbene intermediate generated from MeI and its insertion into the N-H bond, has been ruled out by isotopic labeling.
Malkov
Andrei V
AV
Department of Chemistry, WestChem, University of Glasgow, Glasgow G12 8QQ, UK. a.malkov@lboro.ac.uk
Vranková
Kvetoslava
K
Cerný
Miloslav
M
Kocovský
Pavel
P
D000596:Amino Acids / Q000737:chemistry*; D005563:Formic Acid Esters / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D021241:Spectrometry, Mass, Electrospray Ionization
D000596:Amino Acids; D005563:Formic Acid Esters; C000345:t-butyloxycarbonyl group