2-Arylnaphthoxazole-derived palladium(II) complexes as phosphine-free catalysts for Heck reactions
摘要:
Four air-and moisture-stable new palladium(II) complexes 2a-2c and 4 have been synthesized from easily available 2-aryinaphthoxazole derivatives. The detailed structures of 2c and 4 have been determined by single-crystal X-ray analysis. The Pd-N, Pd-C bonds in palladacycle complexes 2a-2c and the Pd-N, Pd-O bonds in complex 4 form the basis for five- and six-membered chelate rings, respectively. These complexes were applied as efficient phosphine-free catalysts for Heck reactions with aryl bromides and ethyl acrylate. Typically, in the presence of two equivalent n-Bu(4)NB3r, using 0.01% of palladacycle complex 2c as catalyst and two equivalent of K2CO3 as base in DMF at 140 degrees C provided coupled products in moderate to high yields. (c) 2007 Published by Elsevier Ltd.
Microwave-assisted Synthesis of 2-Substituted Naphtho[1,2-d][1,3]oxazoles by Reacting
1-Nitroso-2-naphthol with Allyl Bromides and Benzyl Bromides using FeCl3 as Catalyst
作者:N. Aljaar、S.M. Fraihat、A. Alothman、N.A. Khalaf
DOI:10.14233/ajchem.2020.22745
日期:——
Efficient and improved preparation of 2-substituted[1,2-d][1,3]oxazoles by the reaction of 1-nitroso-2-naphthol and allylbromides, benzylbromides under microwave condition utilizing FeCl3 as a catalyst with yield ranging from 32% to 72%. Reaction with bromo acetonitrile yields the corresponding 2-cyanonaphthoxazole with 58% yield.
Reaction of 1-Nitroso-2-naphthols with α-Functionalized Ketones and Related Compounds: The Unexpected Formation of Decarbonylated 2-Substituted Naphtho[1,2-<i>d</i>][1,3]oxazoles
作者:Nayyef Aljaar、Chandi C. Malakar、Jürgen Conrad、Wolfgang Frey、Uwe Beifuss
DOI:10.1021/jo3022956
日期:2013.1.4
Reactions between 1-nitroso-2-naphthols and α-functionalized ketones such as α-bromo-, α-chloro-, α-mesyloxy-, α-tosyloxy-, and α-hydroxy ketones under basic conditions delivered 2-substituted naphtho[1,2-d][1,3]oxazoles in a single synthetic operation. The product formation was accompanied by the unexpected loss of the C═O group from the α-functionalized ketones. With aryl bromides, allyl bromides
1-亚硝基-2-萘与α-官能化酮如α-溴代,α-氯代,α-甲氧基,α-甲苯磺酰基和α-羟基酮之间的反应在碱性条件下产生了2-取代的萘并[一次合成操作中的1,2- d ] [1,3]恶唑。产物的形成伴随有α-官能化酮中C═O基团的意外损失。以芳基溴化物,烯丙基溴化物,α-溴二酮,α-溴氰化物,α-溴酸酯和α-溴酮酸酯为底物,还观察到了萘并[1,2- d ] [1,3]恶唑的形成。在回流下在1,2-二氯乙烷或乙腈中进行转化,得到相应的萘并恶唑,产率在52%至85%之间。
Abbady,M.A., Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1979, vol. 17, p. 450 - 453
作者:Abbady,M.A.
DOI:——
日期:——
ABBADY M. A., INDIAN J. CHEM., 1979, B 17, NO 5, 450-453