α-Aminated methyllithium by DTBB-catalysed lithiation of a N- (chloromethyl) carbamate

Article abstract of DOI:10.1016/S0040-4020(99)00155-6

The reaction of O-tert-butyl-N-(chloromethyl)-N-methyl carbamate (1) with lithium powder and a catalytic amount of 4,4'-di-tert-butylbiphenyl (DTBB, 2.5 mol %) in the presence of different electrophiles [Me₃SiCl, (i)BuCHO, (t)BuCHO, PhCHO, 4-MeOC₆H₄CHO, (CH₂)₄CO, MeCO(n)Pr, Et₂CO, MeCO(CH₂)₂CH=CH₂, PhCOMe, PhCO(n)Bu, Ph₂CO] in THF at -78°C leads, after hydrolysis with water, to the expected functionalised carbamates 2. Carbamates 2 derived from carbonyl compounds are deprotected with hydrogen chloride (for aromatic aldehyde or ketone derivatives) or with a mixture of phenol and trimethylsilyl chloride (for aliphatic aldehyde derivatives) giving substituted 1,2-diols 4.