Palladium Complexes with Bulky Diphosphine Ligands as Highly Selective Catalysts for the Synthesis of (Bio-) Adipic Acid from Pentenoic Acid Mixtures.
摘要:
A series of sterically bulky diphosphines have been prepared, including P-2 = trans-1,2-bis[(di-tert-butylphosphino)methyllcydohexane (4), (2-methylenepropane1,3-diy1)bis(di-tert-butylphosphine) (5), bis[(di-tertbutylphosphino)methyl]dimethylsilane (6), and cis- and trans11,12-bis [ (di-tert-butylphosphino)methy1]-9,10-dihydro-9,10-ethanoanthracene (10 and 11). The corresponding palladium complexes of these ligands, P2Pd(CF3CO2)(2), have been synthesized and characterized. The solid-state structures of [Pd(4)(CF3CO2)(2)], [Pd(S)(CF3CO2)(2)], [Pd(6)(CF3CO2)(2)], and [Pd(11)(CF3CO2)(2)] were obtained by single-crystal X-ray diffraction and confirm the bidentate binding mode of the ligand and a square-planar coordination geometry with a minor distortion from the ideal. The diphosphines in combination -with Pd(OAc)(2) have been applied in the hydroxycarbonylation of a mixture of pentenoic acid isomers to produce adipic acid with high selectivity (in several cases >95%). The (regio)selectivity of the hydroxycarbonylation reaction is highly dependent on the P-2 diphosphine ligand structure, particularly the steric bulk of the substituents on the diphosphine donor and the P-Pd-P bite angle in the complexes, with respectively tertiary alkyl phosphine substituents (tert-butyl, adamantyl) and a C4 backbone P-Pd-P bite angle >100 degrees being the common features of highly adipic acid selective systems. It is suggested that the regioselectivity of hydroxycarbonylation becomes largely driven by the chelation of the carboxylic acid functionality of pentenoic acid substrates, when smaller size P substituents and/or when P-2 ligands with smaller bite angles (<100 degrees) are applied.
olefin substrates, but virtually no effect of the doublebond position within the substrate. Compared to higher olefins, ethylene carbonylation under identical conditions is much faster, likely due not just to the occurrence of reactive linear acyls exclusively but also to an intrinsically favorable insertion reactivity of the olefin. The alcoholysis reaction is slowed down for higher alcohols, evidenced
PROCESS FOR THE CARBONYLATION OF ETHYLENICALLY UNSATURATED COMPOUNDS, NOVEL CARBONYLATION LIGANDS AND CATALYST SYSTEMS INCORPORATING SUCH LIGANDS
申请人:Eastham Graham Ronald
公开号:US20120330016A1
公开(公告)日:2012-12-27
A novel bidentate ligand of general formula (I) is described together with a process for the carbonylation of ethylenically unsaturated compounds. The group X
1
may be defined as a univalent hydrocarbyl radical of up to 30 atoms containing at least one nitrogen atom having a pKb in dilute aqueous solution at 18° C. of between 4 and 14 wherein the said at least one nitrogen atom is separated from the Q
2
atom by between 1 and 3 carbon atoms. The group X
2
is defined as X
1
, X
3
or X
4
or represents a univalent radical of up to 30 atoms having at least one primary, secondary or aromatic ring carbon atom wherein each said univalent radical is joined via said at least one primary, secondary or aromatic ring carbon atom(s) respectively to the respective atom Q
2
. Q
1
and Q
2
each independently represent phosphorus, arsenic or antimony.
PROCESS FOR PRODUCING PHENYL-SUBSTITUTED HETEROCYCLIC DERIVATIVE THROUGH COUPLING USING TRANSITION METAL CATALYST
申请人:Komiyama Masato
公开号:US20110313169A1
公开(公告)日:2011-12-22
A process for efficiently producing, through few steps either a xanthine oxidase inhibitor, which is a therapeutic agent for hyperuricemia, or an intermediate therefore. The process is a novel coupling process which comprises subjecting a compound represented by formula (1) to coupling reaction with a compound represented by formula (2) in the presence of a transition metal compound to thereby obtain a compound represented by formula (3).
Platinum ethyl complexes with β-agostic Pt–H–C bonding
作者:Nicholas Carr、Laura Mole、A. Guy Orpen、John L. Spencer
DOI:10.1039/dt9920002653
日期:——
Protonation with non-co-ordinating acids of the complexes [Pt(η2-C2H4)(L–L)][L–L =(H11C6)2P(CH2)2P(C6H11)2, 1a, But2P(CH2)2PBut2, 1b, (H11C6)2P(CH2)3P(C6H11)2, 1c, But2P(CH2)3PBut2, 1d or o-But2PCH2C6H4CH2PBut2, 1e] and [PtEt2(L–L)]2a–2d affords a series of cationic platinum(II) complexes 3a–3e which in the case of 3a–3c adopt a cis ethene/hydride ground state whereas in 3d and 3e the otherwise electron-deficient
Preparation and fluxional behaviour of η<sup>3</sup>-methylbenzyl platinum and palladium complexes
作者:Louise E. Crascall、John L. Spencer
DOI:10.1039/dt9920003445
日期:——
of the complexes [M(η2-CH2CHPh)(L–L)][M = Pt, L–L =(C6H11)2P(CH2)nP(C6H11)2, n= 2 or 3 (1a or 1c), But2P(CH2)nPBut2, n= 2 or 3 (1b or 1d), and But2PCH2C6H4CH2PBut2(1e); M = Pd, L–L = But2P(CH2)nPBut2, n= 2 or 3 (1f or 1g) and But2PCH2C6H4CH2PBut2(1h)] with HBF4 in diethyl ether affords a series of complexes, [M(η3-MeCHPh)(L–L)][BF4](2a–2h), which contain an η3-methylbenzyl ligand. The complexes 2a–2h
配合物的质子化[M(η 2 -CH 2 CHPh配合)(L-L)] [M = PT,L-L =(C 6 H ^ 11)2 P(CH 2)Ñ P(C 6 H ^ 11)2,n = 2或3(1a或1c),Bu t 2 P(CH 2)n PBu t 2,n = 2或3(1b或1d)和Bu t 2 PCH 2 C 6 H 4 CH 2PBu t 2(1e); M = Pd,L–L = Bu t 2 P(CH 2)n PBu t 2,n = 2或3(1f或1g)和Bu t 2 PCH 2 C 6 H 4 CH 2 PBu t 2(1h)]]用HBF 4在乙醚中,得到了一系列的复合物,[M(η 3 -MeCHPh)(L-L)] [BF 4 ](2A - 2H),其包含一个η 3-甲基苄基配体。配合物2a – 2h的特征在于1 H,13 C和31 P NMR光谱,发现除2a和2f以外的所有化合物均在室温