Experimental and Computational Study of 6-exo and 7-endo Cyclization of Aryl Radicals Followed by Tandem SRN1 Substitution

PEISINO, L. E.; PIERINI, A. B.

JOURNAL OF ORGANIC CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2013 p. 4719 - 4729

0022-3263

The reaction of N-allyl-N-(2-halobenzyl)-acet-amides and derivatives was investigated in liquid ammoniaunder irradiation with the nucleophiles Me3Sn−, Ph2P− andO2NCH2−. 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 goodyields. These reactions are proposed to occur through theintermediacy of aryl radicals, which by intramolecular 6-exo or7-endo attack to a double bond cyclize to give aliphatic radicals,which react along the propagation steps of the SRN1 chain cycleto afford the cyclic substituted compounds as main products.The reactions were modeled with DFT methods, whichprovide a rational understanding that relates the product distribution to the structure of the aliphatic radicals proposed asintermediates and the kinetic of their formation.