51523-13-8

Upstream product

• 57170-64-6 1-bromo-2-(diphenylphosphinomethyl)benzene 
• 59485-34-6 1,2-bis(2-bromophenyl)ethane 
• 1079-66-9 chloro-diphenylphosphine 

Relevant academic research and scientific papers

Ortho-Lithiated benzyl diorganophosphines [o-(R2PCH2)C6H4Li(Et2O)], R=Ph, Me. Synthesis, structural characterization, and reactions

(o-Lithiobenzyl)dimethylphosphine, [o-(Me2PCH2)C6H4Li(Et 2O)]2 (7), is shown by crystal structure analysis to be dimeric, the two lithium atoms bridging the phenyl ortho-carbon atoms in a four-membered ring structure. A distorted tetrahedral coordination sphere at lithium is completed by coordination of one phosphino group and a molecule of diethylether (triclinic, space group P1?, a=10.986(3), b=11.160(3), c=12.368(4) ?, α=86.04(2), β=89.51(2), γ=83.04(2)°, Z=2). [o-(Me2PCH2)C6H4Li(Et 2O)]2 (7) cleanly reacts in donor solvents like diethylether to the thermodynamically more stable (α-lithiobenzyl)dimethylphosphine [Me2PCHLi(Et2O)C6H5]2 (9) with the same overall composition. Crystal structure analysis of the latter shows each lithium atom to be now bonded in an η2 fashion to the Cbenzyl-Cipso bond of one anion, the diethylether molecule, and to the phosphino group of the second anion thereby resulting in a dimeric structure with a central six-membered ring (triclinic, space group P1?, a=8.482(3), b=9.388(3), c=9.482(3) ?, α=95.42(2), β=91.36(2), γ=104.20(2)°, Z=1). (o-Lithiobenzyl)diphenylphosphine undergoes the same reaction to the corresponding α-lithiobenzylphosphine upon addition of strong donors like N,N,N′,N′-tetramethylethylenediamine (tmeda). Upon addition of Cp2TiCl2, (o-lithiobenzyl)diphenylphosphine reacts to form 1,2-bis[o-(diphenylphosphino)phenyl]ethane, [o-(Ph2P)C6H4CH2]2 (10), the formation of which is thought to proceed by oxidation of the anion [o-(Ph2PCH2)C6H4]- by Cp2TiCl2 to the radical which undergoes a 1,3 shift of the diphenylphosphino group from the sp3 benzyl carbon atom to the sp2 ortho-carbon atom of the phenyl ring to form the more stable benzyl radical. Dimerization of the latter ultimately leads to [o-(Ph2P)C6H4CH2]2 (10) whose molecular structure was determined in the solid state (monoclinic, space group P21/n, a=12.217(2), b=8.382(1), c=15.004(2) ?, β=90.81(1)°, Z=2). The same reaction occurs upon oxidation of (o-lithiobenzyl)diphenylphosphine with ferricinium tetrafluoroborate, [Cp2Fe]+BF4-, thus corroborating the proposed reaction sequence with the transition metal species acting solely as oxidizing agents.

Method for preparing organic carboxylic ester through combined catalysis of aryl bidentate phosphine ligand

The invention discloses a method for preparing organic carboxylic ester by combined catalysis of an aryl bidentate phosphine ligand. The method comprises the following steps: under the action of a palladium compound/aryl bidentate phosphine ligand/acidic additive combined catalyst, carrying out a hydrogen esterification reaction on terminal olefin, carbon monoxide and alcohol so as to generate theorganic carboxylic ester with one more carbon than olefin. According to the invention, by adoption of the palladium compound/aryl bidentate phosphine ligand/acidic additive combined catalyst, good catalytic activity and selectivity for the hydrogen esterification reaction of the olefin are achieved, and olefin carbonylation to synthesize organic carboxylic ester can be efficiently catalyzed. Thearyl bidentate phosphine ligand has a rigid skeleton structure of a rigid ligand and the flexibility of a flexible ligand, so the aryl bidentate phosphine ligand has proper flexibility due to the characteristic that the aryl bidentate phosphine ligand is soft and rigid, and a most favorable coordination mode and a stable active structure in space are favorably formed. In addition, the aryl bidentate phosphine ligand has the advantages of high stability, simple and convenient synthesis method and the like; and a novel industrial technology is provided for production of organic carboxylate compounds.

High- and low-spin chelate complexes of iron featuring κ-C,X-CH2C6H4X (X?= NMe2, PMe2, PPh2) and κ-C,P-CH2PMe2 ligands

Several C,X-chelate complexes of iron were generated via standard metathetical procedures. Treatment of FeCl2 and LnFeCl2 (L = Me2IPr, n = 1; PMe3, n = 2) with anionic equivalents o-LiCH2C6H4NMe2, o-LiCH2C6H4PPh2, and LiCH2PMe2 led to the preparation of [Fe(o-CH2C6H4NMe2)]2(κ-μ-CH2,N-o-CH2C6H4NMe2)2 (1, X-ray), [fac-Fe(κ-C,P-o-CH2C6H4PPh2)3][Li(TMEDA)2] (2, X-ray), (Me2IPr)Fe(CH2C6H4-o-NMe2)2 (3-C,N), [(Me2IPr)2Fe](μ-κ-C,P-CH2PMe2)2[Fe(κ-C,P-CH2PMe2)2] (4, X-ray), and (PMe3)2Fe(κ-C,P-CH2PMe2)2 (5). CH-Bond activation of cis-(Me3P)4FeMe2 with o-CH3C6H4PMe2 led to the generation of trans,cis-(PMe3)2Fe(κ-C,P-CH2C6H4-o-PMe2)2 (6). Exposure of these compounds to [Cp2Fe][PF6], a 1e? oxidant, or AdN3, here construed as a 2e? oxidant, led to degradation in all cases, usually with the generation of carbon-carbon coupled ligands as byproducts. The inability of these systems to permit access to higher iron oxidation states is discussed.