We report herein the use of 3-30 mol% of a new class of tricyclic strong nonionic Lewis bases P (MeNCH2CH2) 3N and P (HNCH2CH2)(i-PrNCH2CH2) 2N for the direct catalytic synthesis of a variety of functionalized α, β-unsaturated nitriles in high yields from aldehydes and acetonitrile or benzyl cyanide at 40-50° C. Evidence for a novel mechanistic pathway proposed for this reaction in a polar protic solvent such as methanol, and a nonpolar ...