1992 年 40 巻 5 号 p. 1090-1093
2-Quinolyl thiocyanate (2) was found to react with C-nucleophiles, i.e., phenylacetonitrile, p-chlorophenylacetonitrile, p-cyanophenylacetonitrile, p-methoxyphenylacetonitrile, ethyl cyanoacetate, and malononitrile, in two ways, depending on the nature of the reagent. The more reactive phenylacetonitrile carbanions attacked at the less reactive sulfur atom, which is less subject to steric effect compared with the 2-position carbon of 2, to give the corresponding sulfides (α-(2-quinolylthio)phenyl- (8), α-(2-quinolylthio)-4-chlorophenyl- (9), α-(2-quinolylthio)-4-cyanophenyl- (10), and α-(2-quinolylthio)-4-methoxyphenylacetonitrile (11)). The less reactive ethyl cyanoacetate and malononitrile carbanions attacked at the more reactive 2-position carbon of 2 to afford the corresponding ipso-substitution products (α-cyano-2-quinolineacetate (4) and 2-quinolinemalononitrile (7)). However, in the reaction of diethyl malonate carbanion, diethyl 2-quinolinemalonate (12) was not obtained, presumably for steric reasons.
