Preparation of piperidine-2-one scaffolds by the hetero-Diels-Alder (HAD) reaction, assisted by microwaves, is described. The versatility of this new approach has been demonstrated by the synthesis of racemic (+/-)-2-phenylpiperidine. Theoretical calculations have allowed us to clarify the factors that govern ring closure to form four-membered rings, arising from a Staudinger-type electrocyclization, and/or six-membered rings through a classical [4+2] HAD cyclization. This competition may be lowered by increasing the electronic demand of the dienophile, as anticipated by the computational studies
S. Long, M. Monari, M. Panunzio, E. Bandini, A. D’Aurizio, A. Venturini (2011). Hetero Diels-Alder (HDA) Strategy for the Preparation of 6-Aromatic- and Heteroaromatic-Substituted Piperidin-2-one Scaffold: Experimental and Theoretical Studies. EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 0, 6218-6225 [10.1002/ejoc.201100930].
Hetero Diels-Alder (HDA) Strategy for the Preparation of 6-Aromatic- and Heteroaromatic-Substituted Piperidin-2-one Scaffold: Experimental and Theoretical Studies
MONARI, MAGDA;
2011
Abstract
Preparation of piperidine-2-one scaffolds by the hetero-Diels-Alder (HAD) reaction, assisted by microwaves, is described. The versatility of this new approach has been demonstrated by the synthesis of racemic (+/-)-2-phenylpiperidine. Theoretical calculations have allowed us to clarify the factors that govern ring closure to form four-membered rings, arising from a Staudinger-type electrocyclization, and/or six-membered rings through a classical [4+2] HAD cyclization. This competition may be lowered by increasing the electronic demand of the dienophile, as anticipated by the computational studiesI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
