Synthesis of sterically hindered enamides via a Ti-mediated condensation of amides with aldehydes and ketones
作者:Julien Genovino、Bharat Lagu、Yaping Wang、B. Barry Touré
DOI:10.1039/c2cc32538a
日期:——
The first TiCl(4)-mediated condensation of secondary amides with aldehydes and ketones has been achieved. The reaction proceeds at room temperature and is complete within 5 h in most cases. The optimized procedure used 5 equiv of an amine base hinting that the in situ activation of both the amide and the Lewis acid is required. The reaction affords polysubstituted (E)-enamides.
The selective construction of new C-C or C-heteroatom bonds is frequently the fundamental step in the synthesis of derivatives with high added value. In particular, molecules with C-N bonds are of great interest clue to their widespread use and intrinsic importance. Of the large number of organic compounds with useful biological activity, organic compounds with C-N bonds are among the most prominent. For instance, the nitrogenated gamma-lactamic heterocycles are the basic structures of many substances used as intermediates in the synthesis of important compounds with pharmacological properties such as psychotropics and antihypertensives as well as others with biological properties. In the present work, we reported for the first time an efficient and eco-friendly alternative to obtain N-substituted-gamma-lactams by carbon-nitrogen coupling of 2-pyrrolidinone and 1-heptanal assisted by microwave irradiation, over activated alkali-Norit carbon catalysts in solvent-free conditions. (C) 2011 Elsevier B.V. All rights reserved.
A Photochemical Two-Step Formal [5+2] Cycloaddition: A Condensation–Ring-Expansion Approach to Substituted Azepanes
作者:Scott Thullen、David Rubush、Tomislav Rovis
DOI:10.1055/s-0036-1589049
日期:2017.12
relatively understudied photochemical rearrangement of N-vinylpyrrolidinones to azepin-4-ones in good yields. This transformation allows for the conversion of readily available pyrrolidinones and aldehydes to densely functionalized azepane derivatives in a facile two step procedure.