Heterocycles from Morita–Baylis–Hillman adducts: synthesis of 5-oxopyrazolidines, arylidene-5-oxopyrazolidines, and oxo-2,5-dihydro-pyrazols
作者:José Tiago M. Correia、Manoel T. Rodrigues、Hugo Santos、Cláudio F. Tormena、Fernando Coelho
DOI:10.1016/j.tet.2012.10.057
日期:2013.1
Starting from Morita–Baylis–Hillman (MBH) adducts, an approach for the synthesis of oxopyrazolidines, arylidene-oxopyrazolidines, and oxo-2,5-dihydropyrazoles is described. The method is based on a tandem process involving a Michaeladdition of amino-guanidine into silylated and acetylated MBH adducts, followed by intramolecular cyclization. The use of acetylated MBH adducts led also to the synthesis
<i>N</i>-Methylpyrrolidone Hydroperoxide/Cs<sub>2</sub>CO<sub>3</sub>as an Excellent Reagent System for the Hydroxy-Directed Diastereoselective Epoxidation of Electron-Deficient Olefins
作者:Napoleon John Victor、Janardhanan Gana、Kannoth Manheri Muraleedharan
DOI:10.1002/chem.201501929
日期:2015.10.12
This report introduces N‐methylpyrrolidone hydroperoxide (NMPOOH)/base as an excellent reagent system for hydroxy‐directed syn selective epoxidation of electron‐deficient olefins, characterized by high diastereoselectivity, short reaction times and remarkable chemoselectivity, especially in presence of oxidatively labile nitrogen or sulfur atoms. NMPOOH also proves efficient in the oxidation of electron‐deficient
Ozonolysis of Morita–Baylis–Hillman adducts originated from aromatic aldehydes: an expeditious diastereoselective approach for the preparation of α,β-dihydroxy-esters
作者:Carlos A.M. Abella、Patrícia Rezende、Michele F. Lino de Souza、Fernando Coelho
DOI:10.1016/j.tetlet.2007.10.149
日期:2008.1
We disclose herein ozonolysis of Morita-Baylis-Hillman adducts originated from aromatic aldehydes. This efficient reaction provides alpha-ketoesters with different substitution patterns on the aromatic ring. Diastercoselective reduction of the corresponding alpha-ketoester obtained in the oxidative cleavage step provides alpha,beta-dihydroxy-esters with excellent degree of anti diastereoselection. The method is simple and easy to execute and is therefore a valuable alternative to prepare either alpha-ketoesters or alpha-dihydroxy-esters. (c) 2007 Elsevier Ltd. All rights reserved.
Antiproliferative effect of Baylis–Hillman adducts and a new phthalide derivative on human tumor cell lines
作者:Luciana K. Kohn、C.H. Pavam、D. Veronese、F. Coelho、J.E. De Carvalho、Wanda P. Almeida
DOI:10.1016/j.ejmech.2006.03.006
日期:2006.6
In this work we report our results concerning the study on the in vitro antiproliferative activity of 18 Baylis-Hillman adducts and some derivatives against a panel of humor tumor cell lines. A brief qualitative structure-activity relationship study indicated that carbon-carbon double bond and the presence of an electron-withdrawing substituent at the aromatic ring are essential for the activity. A quinoline-phthalide derivative has exhibited a potent effect on the proliferation of all cell lines. It is interesting to note their special cytotoxic activity against NCIADR cell line. (c) 2006 Elsevier SAS. All rights reserved.
Diastereoselective heterogeneous catalytic hydrogenation of Baylis–Hillman adducts
作者:Cristiano R Mateus、Wanda P Almeida、Fernando Coelho
DOI:10.1016/s0040-4039(00)00258-6
日期:2000.4
We describe herein our results concerning a highly diastereoselective heterogeneous hydrogenation of Baylis-Hillman adducts obtained from aromatic aldehydes. The results obtained are complementary to those already described for homogeneous catalytic hydrogenation reactions. (C) 2000 Elsevier Science Ltd. All rights reserved.