Palladium-Catalyzed Alkoxycarbonylation of Arylsulfoniums
摘要:
Alkoxycarbonylation of arylsulfoniums has been developed with the aid of a catalytic amount of a palladium-Xantphos complex under an atmospheric pressure of CO gas. Various functional groups such as carbonyl, cyano, halo, and sulfonyl groups were well tolerated under the present catalysis. Since aryldimethylsulfoniums were readily prepared from the corresponding aryl methyl sulfides and methyl triflate, one-pot alkoxycarbonylation of aryl methyl sulfides could be accomplished.
An effective method for alkoxycarbonylation of (hetero)aryl bromides is developed in the presence of in situ-generated phosphinite ligands tBu2POR (R = nBu, nPr, Et or Me). For this purpose commercially available tBu2PCl was used as the pre-ligand in the presence of different alcohols. For the first time cross coupling reactions with two alcohols – one generating the ligand, the other used as substrate
在原位生成的次膦酸酯配体t Bu 2 POR(R = n Bu,n Pr,Et或Me)存在下,开发了一种用于(杂)芳基溴的烷氧羰基化的有效方法。为此目的,在不同醇存在下,将可商购的t Bu 2 PC1用作预配体。首次开发了与两种醇的交叉偶联反应-一种生成配体,另一种用作底物。通过这种方法,可以以更有效的方式进行配体优化,并且可以以良好的产率和选择性获得所需的产物。
N‐Heterocyclic Carbene Catalyzed Ester Synthesis from Organic Halides through Incorporation of Oxygen Atoms from Air
Oxygenation reactions with molecular oxygen (O2) as the oxygen source provides a green and straightforward strategy for the construction of O‐containing compounds. Demonstrated here is a novel N‐heterocyclic carbene (NHC) catalyzed oxidative transformation of simple and readily available organic halides into valuable esters through the incorporation of O‐atomsfromO2. Mechanistic studies prove that
Green and Efficient: Iron-Catalyzed Selective Oxidation of Olefins to Carbonyls with O<sub>2</sub>
作者:Angela Gonzalez-de-Castro、Jianliang Xiao
DOI:10.1021/jacs.5b03956
日期:2015.7.1
A mild and operationally simple iron-catalyzed protocol for the selective aerobic oxidation of aromatic olefins to carbonyl compounds is described. Catalyzed by a Fe(III) species bearing a pyridine bisimidazoline ligand at 1 atm of O2, α- and β-substituted styrenes were cleaved to afford benzaldehydes and aromatic ketones generally in high yields with excellent chemoselectivity and very good functional
A general palladium-catalyzed alkoxycarbonylation of aryl and heteroarylbromides has been developed in the presence of bulky monodentate phosphines. Studies of the butoxycarbonylation of three model substrates revealed the advantages of di-1-adamantyl-n-butylphosphine compared to other ligands. In the presence of this catalyst system various bromoarenes provided the corresponding benzoic acid derivatives
Process for the preparation of carboxylic acid esters from organic
申请人:The University of Delaware
公开号:US03988358A1
公开(公告)日:1976-10-26
Carboxylic acid esters or amides are obtained from aryl, heterocyclic, vinylic, ethynylic, and benzylic halides and substituted derivates thereof, by reacting same with an alcohol or primary or secondary amine and carbon monoxide, in the presence of a palladium catalyst and if necessary a tertiary amine at about 20.degree.-150.degree. C and from about a half to about 100 atmospheres pressure. A typical example is the conversion of bromobenzene into n-butyl benzoate at 100.degree. C and one atmosphere of carbon monoxide in the presence of tri-n-butyl-amine and a catalytic amount of PdBr.sub.2 [P(C.sub.6 H.sub.5).sub.3 ].sub.2.