Application of the Catalytic Friedel-Crafts Acylation Reaction and Regioselectivity Correlations
作者:Mark Wilkinson、Fabienne Saez、Wei Hon
DOI:10.1055/s-2006-939705
日期:——
A correlation was found between electronic properties and regioselectivity in the Friedel-Crafts reaction of substituted phenylacetic and benzoic acids with anisole, utilising substoichiometric (down to 1 mol%) amounts of catalyst. Relative reactivities of selected catalysts for this reaction were also studied.
Trifluoroacetic acid-catalysed transacylation of arenes by acylpentamethylbenzene
作者:Takashi Keumi、Toshio Morita、Takanobu Shimada、Naomi Teshima、Hidehiko Kitajima、G. K. Surya Prakash
DOI:10.1039/p29860000847
日期:——
by the mixed anhydride. The mechanism resulting in an ipso-protonated intermediate B was deduced from the reaction of acetylmesitylene with [2H]TFA as well as from the rate of deacetylation of 3,5-dideuterioacetylmesitylene with TFA. The formation of such an intermediate was also independently confirmed by 13C n.m.r. spectroscopic studies on AcPMB in superacid solutions under stable ion conditions.
发现在沸腾的三氟乙酸(TFA)中发生酰基戊二甲基苯与活化的芳烃(如苯甲醚)之间的容易的转酰基作用。通过产物分离和动力学阐明了乙酰戊五甲基苯(AcPMB)和苯甲醚与TFA的转酰化机理。该反应进行经由AcPMB的可逆protodeacetylation涉及的本位-protonated中间体B,得到五甲基苯和乙三氟乙酸酐,接着通过混合酸酐苯甲醚不可逆乙酰化。从而导致该机构本位-protonated中间体B由acetylmesitylene与[反应推导2H] TFA以及3,5-二氘代乙酰基乙酰间苯三甲与TFA的脱乙酰速率。这种中间体的形成还通过在稳定离子条件下在超酸溶液中对AcPMB的13 C nmr光谱研究独立地证实。
Aluminum Bases for the Highly Chemoselective Preparation of Aryl and Heteroaryl Aluminum Compounds
作者:Stefan H. Wunderlich、Paul Knochel
DOI:10.1002/anie.200804966
日期:2009.2.9
Selective CH activation with a series of neutral aluminum trisamide bases led to a wide range of polyfunctional aryl and heteroarylaluminum reagents. Ester and cyano groups are stable under the reaction conditions for this direct alumination, and donor oxygen substituents are efficient directing groups. High metalation regioselectivities were observed with O,S and N,S heterocycles (see example).
Aromaticketones were efficiently prepared in good yields by the reactions of aryl bromides with n-BuLi, followed by the reactions with aromaticaldehydes or aliphatic aldehydes and the subsequent treatment with molecular iodine and K2CO3, in a one-pot method. The same treatment of arenes, instead of aromatic bromides, also provided the corresponding aromaticketones in good yields. Using these methods
通过一锅法,通过芳基溴化物与n- BuLi的反应,然后与芳族醛或脂族醛的反应,以及随后用分子碘和K 2 CO 3的处理,可以有效地以高收率高效地制备芳族酮。芳烃的相同处理而不是芳族溴化物也以良好的产率提供了相应的芳族酮。使用这些方法,可以通过简单,无过渡金属且因此对环境无害的实验程序有效地制备各种带有富电子芳族化合物和缺电子芳族化合物的二芳基酮和烷基芳基酮。
A General Synthesis of Diarylketones by Means of a Three-Component Cross-Coupling of Aryl and Heteroaryl Bromides, Carbon Monoxide, and Boronic acids
Pd(OAc)2/di-1-adamantyl-n-butylphosphine (cataCXium A) is highly active in the three-component Suzuki carbonylation and represents the most general catalyst system reported up to now. A broad range of aryl/heteroarylbromides and aryl boronic acids can be coupled to the corresponding diarylketones at low catalyst loadings.