Mechanistic study of 7-endo selective radical cyclization of the aryl radical

A new and facile approach to 1,2-dihydroisoquinolin-3(4H)-imines by the Cu(i)-catalyzed reaction of 2-ethynylbenzyl methanesulfonates, sulfonyl azides and amines

A new, step-economical and operationally simple access to unsubstituted 1,2-dihydroisoquinolin-3(4H)-imines by Cu-catalyzed MCRs under mild conditions is described.

Experimental and computational study of 6-exo and 7-endo cyclization of aryl radicals followed by tandem S(RN)1 substitution

The reaction of N-allyl-N-(2-halobenzyl)-acetamides and derivatives was investigated in liquid ammonia under irradiation with the nucleophiles Me3Sn(-), Ph2P(-) and O2NCH2(-). Following this procedure, novel substituted 2-acetyl-1,2,3,4-tetrahydroisoquinolines and substituted 2-acetyl-2,3,4,5-tetrahydro-1H-benzo[c]azepines were obtained in good yields. These reactions are proposed to occur through the intermediacy of aryl radicals, which by intramolecular 6-exo or 7-endo attack to a double bond cyclize to give aliphatic radicals, which react along the propagation steps of the S(RN)1 chain cycle to afford the cyclic substituted compounds as main products. The reactions were modeled with DFT methods, which provide a rational understanding that relates the product distribution to the structure of the aliphatic radicals proposed as intermediates and the kinetic of their formation.