Alkylaluminum cyanides as potent reagents for hydrocyanation

Actuating Cycloaromatization of a Bicyclo[7.3.1]enediyne by Annelation: An Example of Inverse Dependence on Bridge Atom Hybridization

“…[12] Spectroscopic analysis indicates that 6 resides exclusively in its hemiacetal form. Hydrocyanation of 6 using Et 2 AlCN according to the method of Nagata [13] gives adduct 7, which was monosilylated under forcing conditions to afford the tertbutyldiphenylsilyl (BPS) derivative 8. Examination of molecular models suggested that the 1,2-addition of an acetylide anion to C(2) of 8 might proceed stereoselectively to give the axial alkyne required for enediyne installation.…”

Cd → BCD → Abcd

“…By adding ammonium chloride to offset this developing basicity, the intended products 98 and 99 (Scheme 12-12) could be isolated, after ketalization and acetylation, in 40 and 24% yield, respectively. Further efforts to improve the stereoselectivity of this reaction [87][88][89][90][91] led to the discovery that the combination of triethylaluminum and hydrogen cyanide (or, preferably, diethylaluminum cyanide) in aprotic solvents effected addition of cyanide ion to 96 in yields as high as 80% with greater than 90% stereoselectivity for the 13/?-cyano epimer.…”

Homologation of ketones into carboxylic acids

“…Addition of the one carbon unit via cyanohydrins is one of the classical methods for introduction of the one carbon unit. Addition of cyanide to the ketone can occur using sodium 82 /potassium 83 cyanide or diethylaluminum cyanide 84. Hsai et al used this methodology to prepare a spin labeled probe,82 Scheme 18.Sodium cyanide was added to 81 to give the cyanohydrin 82 in quantitative yield.…”