Xiangfu Lan

A new route to N-substituted heterocycles

Abstract N-(Benzotriazol-1-ylmethyl)-indole, - pyrrole, -carbazole, and -benzimidazole, and analogs substituted in the methylene group are converted by lithium aluminum hydride, or by Grignard reagents, or in two cases by organozinc reagents, into the N-substituted heterocycles in good yields.

Novel routes to 4-substituted N,N-dialkylanilines, N-alkylanilines and anilines

Abstract 4-(Benzotriazol-1-ylmethyl)-N,N-dialkylanilines, -N-alkylanilines, -anilines and some substituted analogs obtained via lithiation are converted by lithium aluminum hydride or Grignard reagents into 4-substituted N,N-dialkylanilines, N-alkylanilines and anilines, respectively, in good yields.

Benzotriazole-assisted β-lithiation of vinyl ethers

Abstract Benzotriazole-assisted β-deprotonation of (α-benzotriazolylvinyl) ethers occurs stereoselectively at the cis position as shown by quenching with a variety of electrophiles. Semiempirical calculations of the lithiated enol ethers by PM3 and MNDO methods disclosed a higher stabilization for the cis-isomers over the corresponding trans-isomers.

A New and Efficient Conversion of Alkylphenols into the Corresponding Substituted Salicylic Acids

Abstract A three-step sequence suitable for the synthesis of alkyl substituted salicylic acids from the corresponding alkylphenols involves ortho-directed lithiation of the methoxymethyl aryl ethers followed by quenching with carbon dioxide and deprotection under acidic conditions.