Rationally Designed Pincer-Type Heck Catalysts Bearing Aminophosphine Substituents: Pd<sup>IV</sup>Intermediates and Palladium Nanoparticles
作者:Jeanne L. Bolliger、Olivier Blacque、Christian M. Frech
DOI:10.1002/chem.200800441
日期:2008.9.8
catalytic cycle of the Heck reaction, their general existence as reactive intermediates (for example, in other reactions) cannot be excluded. On the contrary, they were shown to be thermally accessible. Compounds 1 and 2 show a smooth halideexchange with bromobenzene to yield their bromo derivatives in DMF at 100 degrees C. Experimental observations revealed that the halideexchange most probably proceeded
氨基膦基钳形配合物[C6H3-2,6-(XP(哌啶基)2)2Pd(Cl)](X = NH 1; X = O 2)可以很容易地由廉价的起始原料通过依次添加1,1在“一锅”中,在N 2下,将',1''-膦三基三哌啶和1,3-二氨基苯或间苯二酚制得[Pd(cod)(Cl)2](cod =环辛二烯)在甲苯中的溶液。事实证明,化合物1和2是出色的Heck催化剂,可以在很短的反应时间和较低的催化剂负载量下,在140℃下将数种电子失活和空间位阻的芳基溴化物与各种烯烃作为偶联伴侣进行定量偶联。升高的反应温度还使得在仅0.01mol%的催化剂存在下,烯烃能够与电子失活的和位阻的芳基氯有效地偶联。进行的机理研究排除了均相的Pd 0配合物是1和2的催化活性形式。另一方面,钯纳米颗粒参与催化循环得到了有力的实验支持。即使衍生自1(和2)的钳型Pd IV中间体不参与Heck反应的催化循环,也不能排除它们作为反应性中
Facile route to dihydroindacene type ligands using multiple Heck reactions on aryl polybromides
The Heck reaction of aryl dibromides and n-butyl acrylate catalyzed by Pd(OAc2/pO-Bu), is a high yielding method to produce intermediates for dihydroindacene type ligands. The same synthetic strategy, extended to tribromides, represents a simple route also to tridentate ligands potentially useful in the stabilization of trimeric metal complexes and clusters. (C) 2002 Elsevier Science Ltd. All rights reserved.
Palladium-Catalyzed Desulfitative Mizoroki-Heck Couplings of Sulfonyl Chlorides with Mono- and Disubstituted Olefins: Rhodium-Catalyzed Desulfitative Heck-Type Reactions under Phosphine- and Base-Free Conditions
作者:Srinivas Reddy Dubbaka、Pierre Vogel
DOI:10.1002/chem.200400838
日期:2005.4.22
olefins with arenesulfonyl and trifluoromethanesulfonyl chlorides. Thus (E)-1,2-disubstituted alkenes with high stereoselectivity and 1,1,2-disubstituted alkenes with 12:1 to 21:1 E/Z steroselectivity can be obtained. Herrmann's palladacycle at 0.1 mol % is sufficient to catalyze these reactions, for which electron-rich or electron-poor sulfonylchlorides and alkenes are suitable. If phosphine- and base-free