A Convenient Preparation of 2-Aroyl-3,3-bis(alkylsulfanyl)acrylaldehydes and Their Application in the Synthesis of 5-Aroyl-2-oxo-1,2-dihydro-2-pyridinecarbonitriles
Regiodivergent heterocyclization: a strategy for the synthesis of substituted pyrroles and furans using α-formyl ketene dithioacetals as common precursors
作者:Ting Wu、Ling Pan、Xianxiu Xu、Qun Liu
DOI:10.1039/c3cc48546c
日期:——
challenging task. We report here that 5-alkylthio-pyrroles, 4-alkylthiocarbonyl-pyrroles and 2-alkylthio-4-tosyl-furans can be prepared, selectively, in a single operation using the readily available alpha-formyl ketene dithioacetals as common precursors, through their regiodivergent heterocyclization with alpha-acidic isocyanides controlled by the choice of suitable catalysts/promoters.
A new strategy for the synthesis of 2,3,5-trisbustituted furans from alpha-formylketene dithioacetals is described. The protocol involves a facile conversion of alpha-formylketene dithioacetals to vinylketene dithioacetals via Wittig reaction and subsequent N-bromosuccinimide-mediated cyclization to 2,3,5-trisbustituted furans. Further conversion of the 2-thioalkylfurans thus obtained to 2-aminofurans shows the potential synthetic utility of this new approach. (c) 2011 Elsevier Ltd. All rights reserved.
A Convenient Preparation of 2-Aroyl-3,3-bis(alkylsulfanyl)acrylaldehydes and Their Application in the Synthesis of 5-Aroyl-2-oxo-1,2-dihydro-2-pyridinecarbonitriles
作者:Chittoorthekkathil V. Asokan、Engoor R. Anabha
DOI:10.1055/s-2005-918491
日期:——
The reaction of aroylketene dithioacetals 1 with Vilsmeier-Haack reagent, prepared from POCl3 and DMF, under mild conditions gave 2-aroyl-3,3-bis(alkylsulfanyl)acrylaldehydes 2 in excellent yields. Cyclization of 2-[2-aroyl-3,3-bis(methylsulfanyl)-2-propylidene]malononitriles 3, derived from 2 and malononitrile, in the presence of concentrated hydrochloric acid in tertiary butanol afforded 2-pyridone derivatives 4.
The reaction of 2-aroyl-3,3-bis(alkylsulfanyl)acrylaldehydes and hydroxylamine hydrochloride: Facile synthesis of differently substituted isoxazoles
作者:Annie Mathews、Karunalayam A. Sasikala、Sholly C. George、Kooramattom U. Krishnaraj、Naduthottiyil K. Sreedevi、Marathu Prasanth、Engoor R. Anabha、Karakkattu S. Devaky、Chittoorthekkathil V. Asokan
DOI:10.1002/jhet.5570450605
日期:2008.11
3-(methylsulfanyl)-5-phenyl-4-isoxazolecarbonitriles and 5-aryl-3-(methylsulfanyl)-4-isoxazolecarbaldehyde oximes in good yields by varying the substratereagent stoichiometry and temperature of the reaction medium.