Phosphine-Directed sp3 C–H, C–O, and C–N Borylation
摘要:
Benzylic C-H borylation reactions are limited, requiring new approaches to exploit their reactivity for efficient selective functionalization. The recent development of phosphine-directed C-H borylation of arenes has now been extended to benzylic substrates, providing high yield of the mono- and geminal bis-borylation products. Attempts to borylate the C-H bond a to a benzylic ether or amine resulted in C-O and C-N borylation, followed by C-H borylation to provide geminal bis-borylated products.
Substituted sulfonamide compounds corresponding to the formula I:
processes for the preparation thereof, pharmaceutical composition containing these compounds and the use of substituted sulfonamide compounds for the preparation of pharmaceutical compositions.
Phosphorus heterocycles. Part I. A conjugated cyclic methylenephosphorane
作者:E. A. Cookson、P. C. Crofts
DOI:10.1039/j39660002003
日期:——
The cyclic quaternary phosphonium salt 9,10-dihydro-9,9-diphenyl-9-phosphoniaphenanthrene bromide reacts with aqueous sodium hydroxide to give the corresponding cyclic methylenephosphorane as an incompletely characterised orange solid, the relative stability towards hydrolysis of which compared with its acyclic analogue, benzylidenetriphenylphosphorane, suggests some aromatic character in the phosphorus-containing
Synthesis and Characterization of New Intramolecular C−H Activated Rhodium(III) and Iridium(III) Complexes Containing Functionalized Triphenylphosphines
their reactions with different Rh(I) and Ir(I) precursor complexes have been investigated. It is shown that both DPBE and DPES are capable of undergoing oxidative metal insertions at the benzylic positions with the displaced protons appearing as apical hydride ligands in the resulting octahedral complexes. The solution structures of all oxidative addition adducts have been unambiguously identified by
半不稳定的叔膦醚和膦酸酯化合物o- Ph 2 PC 6 H 4 CH 2 OMe(DPBE)和o- Ph 2 PC 6 H 4 CH 2已研究了OC(O)Et(DPES)及其与不同Rh(I)和Ir(I)前体配合物的反应。结果表明,DPBE和DPES都能够在苄基位置发生氧化性金属插入,在生成的八面体络合物中,置换的质子表现为顶氢化物配体。所有氧化加成加合物的溶液结构已通过各种NMR技术明确鉴定。另外,已经对络合物[RhCl(2,5-NBD)(DPES)]和[IrH(1,5-COD)(DPES)] [BF 4 ]进行了单晶X射线衍射研究。
The influence of metal coordination on ligand geometry: The structures of 2-(diphenylphosphino)benzylmethylether and bis(2-(diphenylphosphino)benzylmethylether)palladium(II)triflate
作者:Carlaxel Andersson、Johan Friedrich、Maria H. Johansson、Åke Oskarsson
DOI:10.1016/s0022-2860(98)00608-5
日期:1999.4
Abstract The structures of 2-(diphenylphosphino)benzylmethylether (1) and bis(2-(diphenylphosphino)benzylmethylether)palladium(II)triflate (2) have been determined by X-ray crystallography. The Pd-compound (2) is a potential catalyst in organic synthesis and was prepared by treating tetrakisacetonitrile-palladium-bistriflate with 2-(diphenylphosphino)benzylmethylether in toluene for 16 h at room temperature
摘要 2-(二苯基膦基)苄基甲基醚(1)和双(2-(二苯基膦基)苄基甲基醚)钯(II)三氟甲磺酸盐(2)的结构已通过X射线晶体学确定。Pd-化合物 (2) 是有机合成中的潜在催化剂,通过在室温下用 2-(二苯基膦基)苄基甲基醚在甲苯中处理四乙腈-钯-双氟甲磺酸酯 16 小时制得。有机化合物(1)在单斜空间群P21/a结晶,晶胞尺寸a=7.873(2) A, b=14.805(3) A, c=14.262(5) A, β=91.34(3)°, V=1662.0(8) A3 和 Z=4。Pd-化合物 (2) 在三斜空间群中结晶。P1 晶胞尺寸 a=10.2886(6), b=13.951(1), c=15.6339(9) A, α=89.171(5), β=73.791 (5), γ=83.463(6)°, V=2140.5(2) A3 和 Z=2。两种结构均通过直接方法求解,改进后的 (1)
Stereocontrol in the synthesis of cyclic amino acids: a new ligand for directed hydrogenation through hydrogen bonding
作者:Vasudeva Rao Gandi、Bao Nguyen Do Doan、Sivarajan Kasinathan、Roderick W. Bates
DOI:10.1039/c9ob00003h
日期:——
for the directed hydrogenation of nitrogen heterocycles is described in which hydrogen is delivered cis to a hydroxymethyl group by a rhodium catalyst with a simple phosphine ligand. The chemistry is applied to the synthesis of the hygric acid moiety of lincomycin and the pipecolic acid moiety of Argatroban. A series of control experiments indicate that the stereoselectivity is a result of a combination