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
Hetero Diels-Alder (HDA) Strategy for the Preparation of 6-Aromatic- and Heteroaromatic-Substituted Piperidin-2-one Scaffold: Experimental and Theoretical Studies / S. Long; M. Monari; M. Panunzio; E. Bandini; A. D’Aurizio; A. Venturini;. - In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY. - ISSN 1434-193X. - STAMPA. - 0:(2011), pp. 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.
