6263-01-0Relevant articles and documents
Metalated Nitrogen Derivatives of Carbonic Acid in Organic Synthesis, XV. - 2-Azaallyl Anions from Dialkyl N-(Benzyl)imidodithiocarbonates, -monothiocarbonates, and -carbonates as α-Benzylamine Anion Equivalents
Hoppe, Dieter,Beckmann, Ludger
, p. 1751 - 1764 (2007/10/02)
S,S'-Dimethyl N-(benzyl)imidodithiocarbonate (4a) was deprotonated by means of potassium tert-butoxide in THF or butyllithium in THF/HMPTA/hexane to give the 2-azaallyl anion 7a.Its alkylation yields mixtures of the α- and γ-substitution products 11a and 14a.In contrast, anion 7b, obtained from the S,S'-diethyl derivative 4b, is trapped by electrophiles predominantly in α-position, yielding 11b with high regioselectivity.Thus 4b constitutes a synthetic equivalent for α-metalated benzylamine 1.The less acidic O,O'-and O,S-dialkyl derivatives 5 or 6 were also dep rotonated and alkylated to give only α-adducts 12 or 13 via anions 8 or 9. - Lithium diisopropylamide under kinetic control predominantly abstracts a proton from an S-methyl group of 4a.The intermediate lithium compound 21 was trapped as silane 23 (besides 14aa). - Some further deprotonation experiments were also performed with the imino compounds 11aa, 11ab, 32a, and 32b in order to explore the scope of the metalation reaction.
