Stereoselective syntheses of pyrrolidines and piperidinesbearinghydrophobic chains have been achieved through a metal free, Lewisacid-mediated 5/6-endo-dig reductive hydroaminationcascade of enynyl amines. The brevity of the developed strategy allowedfor the collective stereoselective total synthesis of various alkaloids,including (& PLUSMN;)-pyrrolidine cis-225H, (& PLUSMN;)-epi-197B, (& PLUSMN;)-epi-225C, the familyof (+)-solenopsins and (+)-isosolenopsins, and the formal synthesisof (& PLUSMN;)-bgugaine and (+)-azimic acid.