Synthesis and characterization of {[(COD)Rh(bis-(2R,3R)-2,5-diethylphospholanobenzene)]+BARF−} for use in homogeneous catalysis in supercritical carbon dioxide
摘要:
Reaction of [(COD)(2)Cl2Rh] (COD: cyclo-octadiene) with sodium tetrakis((3,5-trifluoromethyl)phenyl)borate (NaBARF) in the presence of an excess of COD yields [(COD)(2)Rh](+)BARF(-). The COD ligands are readily displaced by the bidentate ligand 1,2-bis((2R,5R)-2,5-diethylphosphalono)benzene (Et-DuPHOS) to form [(COD)Rh(Et-DuPHOS)]BARF, the structure of which has been determined by X-ray crystallography. BARF was selected as the counterion in order to achieve solubility in supercritical carbon dioxide for use in asymmetric hydrogenation and hydroformylation reactions. Density-functional theory calculations were used to study the intermediates in asymmetric hydroformylation of styrene. The energies of the two-enantiomer models differ by 11.3 kcal mol(-1). (C) 2001 Elsevier Science B.V. All rights reserved.
Intermolecular Hydroacylation: High Activity Rhodium Catalysts Containing Small-Bite-Angle Diphosphine Ligands
作者:Adrian B. Chaplin、Joel F. Hooper、Andrew S. Weller、Michael C. Willis
DOI:10.1021/ja211649a
日期:2012.3.14
rhodium complexes containing methylene bridged diphosphine ligands, viz. [Rh(C(6)H(5)F)(R(2)PCH(2)PR'(2))][BAr(F)(4)] (R, R' = (t)Bu or Cy; Ar(F) = C(6)H(3)-3,5-(CF(3))(2)), are shown to be practical and very efficient precatalysts for the intermolecularhydroacylation of a wide variety of unactivated alkenes and alkynes with β-S-substitutedaldehydes. Intermediate acyl hydride complexes [Rh((t)Bu(2)PCH
A convenient method for the generation of {Rh(PNP)}<sup>+</sup> and {Rh(PONOP)}<sup>+</sup> fragments: reversible formation of vinylidene derivatives
作者:Matthew R. Gyton、Thomas M. Hood、Adrian B. Chaplin
DOI:10.1039/c8dt05049j
日期:——
PONOP pincer ligands 2,6-bis(di-tert-butylphosphinomethyl)pyridine and 2,6-bis(di-tert-butylphosphinito)pyridine in the weakly coordinating solvent 1,2-F2C6H4 are shown to be an operationally simple method for the generation of reactive formally 14 VE rhodium(I) adducts in solution. Application of this methodology enables synthesis of known adducts of CO, N2, H2, previously unknown water complexes, and
[Rh(COD) 2 ][BAr F 4 ] 与 PNP 和 PONOP 钳形配体 2,6-双(二叔丁基膦基甲基)吡啶和 2,6-双(二叔丁基膦基)吡啶的取代反应弱配位溶剂 1,2-F 2 C 6 H 4被证明是一种在溶液中生成反应性形式为 14 VE 铑( I ) 加合物的操作简单的方法。应用该方法可以合成已知的 CO、N 2、H 2加合物、以前未知的水络合物和新型亚乙烯基衍生物 [Rh(pincer)(CCHR)][BAr F 4 ] (R =t Bu, 3,5- t Bu 2 C 6 H 3 ),通过与末端炔烃的可逆反应。
Well-Defined and Robust Rhodium Catalysts for the Hydroacylation of Terminal and Internal Alkenes
作者:Amparo Prades、Maitane Fernández、Sebastian D. Pike、Michael C. Willis、Andrew S. Weller
DOI:10.1002/anie.201503208
日期:2015.7.13
A Rh‐catalyst system based on the asymmetric ligand tBu2PCH2P(o‐C6H4OMe)2 is reported that allows for the hydroacylation of challenging internalalkenes with β‐substituted aldehydes. Mechanistic studies point to the stabilizing role of both excess alkene and the OMe‐group.
据报道,基于不对称配体t Bu 2 PCH 2 P( o -C 6 H 4 OMe) 2的 Rh 催化剂系统可以用 β 取代醛对具有挑战性的内烯烃进行加氢酰化。机理研究指出了过量烯烃和 OMe 基团的稳定作用。
Small bite-angle 2-phosphinophosphinine ligands enable rhodium-catalysed hydroboration of carbonyls
作者:Robert J. Newland、Jason M. Lynam、Stephen M. Mansell
DOI:10.1039/c8cc01880d
日期:——
2-Phosphinophosphinine ligands generate Rh catalysts for the hydroboration of ketones and imines in contrast to standard phosphine ligands.
作者:Ariadna Campos-Carrasco、Clara Tortosa-Estorach、Anna M. Masdeu-Bultó
DOI:10.1016/j.inoche.2012.01.010
日期:2012.4
Abstract Rh(I) cyclooctadiene (cod) and carbonyl complexes with fluorinated 2,2′-bipyridines (N-N) have been prepared. The fluorinated tail was introduced as an alky group or through an ester function in the 4,4′- or 5,5′-positions. The X-ray structure of the cyclooctadiene complexes [Rh(cod)(4)][PF6] and [Rh(cod)(L4)][PF6] shows the square-planar coordination around the metal centre, and, in the case