Diphelnylphosphinoyl (-P(=O)Ph(2)) and diphenylthiophosphinoyl (-P(=S)Ph(2)) respectively are modest and strong p-effect functionalities. When these groups are antiperiplanar to mesylate, the substrates solvolyze through unimolecular ionization. In contrast, substrates with the synclinal (gauche) arrangement react bimolecularly with solvent. The anti/gauche rate ratio is 440 for the oxide and 3.2 x 10(6) for the sulfide at 25 degrees C. The antiperiplanar sulfide in fact reacts 220 times more rapidly than the analogous cyclohexyl substrate at 25 degrees C, despite the strong electron-withdrawing nature of diphenylthiophosphinoyl. The a-secondary hydrogen/deuterium kinetic isotope effects of 1.21 for the anti oxide and 1.26 for the anti sulfide suggest kigh sp(2) character in the transition state, as expected for stabilization by hyperconjugation in a vertical mechanism. Energies calculated at the MP2 level show that the geometry with the P-C bond parallel to the empty carbocation p orbital is more stable than the perpendicular geometry by 22.94 kcal mol(-1) for PH2, 8.80 kcal mol(-1) for P(O)H-2, and 10.54 kcal mol(-1) for P(S)H-2, confirming significant hyperconjugation for these substituents. The global minimum, however, is the bridged structure (four-membered rings for the oxide and sulfide, three-membered ring for the simple phosphine), so that the mechanistic choice between a vertical mechanism (hyperconjugation) and a nonvertical mechanism (bridging) is not clear-cut.
A Simple Building‐Block Route to (Phosphanyl‐carbene)palladium Complexes via Intermolecular Addition of Functionalised Phosphanes to Isocyanides
作者:Michael R. Eberhard、Bart van Vliet、Laura Durán Páchon、Gadi Rothenberg、Graham Eastham、Huub Kooijman、Anthony L. Spek、Cornelis J. Elsevier
DOI:10.1002/ejic.200801067
日期:2009.4
(phosphanyl-carbene)PdII complexes. These complexes have bidentate ligands containing an acyclic diamino- or aminooxy-carbene and a phosphane. The synthesis gives good yields (typically 70-90 %) for a variety of complexes (22 compounds). Moreover, it does not require the synthesis of imidazolium salts nor the a priori generation of free carbenes. Three of the new complexes were tested as catalysts
我们提出了一个简单的协议来制造 (phosphanyl-carbene)PdII 复合物。这些配合物具有包含无环二氨基-或氨基氧基-卡宾和磷烷的双齿配体。该合成为各种复合物(22 种化合物)提供了良好的产率(通常为 70-90%)。此外,它不需要合成咪唑鎓盐,也不需要预先生成游离卡宾。三种新配合物被测试作为 Sonogashira 和 Hay 偶联反应的催化剂,具有良好的产率和选择性。
A Cyclopropenethione-Phosphine Ligation for Rapid Biomolecule Labeling
作者:R. David Row、Jennifer A. Prescher
DOI:10.1021/acs.orglett.8b02296
日期:2018.9.21
Cyclopropenethiones are reported as new bioorthogonal reagents. These motifs react readily with substituted phosphines to provide thiocarbonyl adducts. In some cases, the ligations are >300-fold faster than analogous reactions with bioorthogonal cyclopropenones. Dialkyl cyclopropenethiones are also stable in aqueous buffers and can be used for biomolecule labeling in vitro and in cell lysate. The rapid
Elution of compounds [PdCl3-ClC6H3CHNCH(Me)Ph}trans-2-PPh2(CyOH)}] 5a and [PdXC6H4CH(Me)NH2}Ph2PCH(OMe)Ph}] 6b, containing the racemic phosphines as ligands, through a SiO2 column allows the separation of the two diastereoisomers. Opticallyactive coordination complexes trans-[PtCl2Ph2PCH(OMe)Ph}2] and trans-[PtCl2Ph2PCH(OMe)Ph}(PPh3)], have been obtained by ligand transfer reactions between
Ligands with cycloalkane backbones II. Chelate ligands from 2-(diphenylphosphinyl) cyclohexanol: Syntheses and transition metal complexes
作者:Catherine L. Thurner、Michael Barz、Michael Spiegler、Werner R. Thiel
DOI:10.1016/s0022-328x(97)00013-2
日期:1997.8
1 and 3 with chlorodiphenyl phosphine led to newchiral bidentate ligands, bearing a phosphinite donor fragment. Several new transition metal complexes of these ligands were characterized spectroscopically and by X-ray structure analysis.
从PPh 3(Ph = C 6 H 5),锂金属和环氧环己烷开始,通过一锅法反应以约80%的产率获得(±)-2-(二苯基膦基)环己醇(1)。膦部分的氧化。与元素硫或与过氧化氢。得到相应的硫化膦3。氧化物2。后者形成固态的二聚体。1和3的OH片段与氯二苯基膦的反应生成新的手性双齿配体,带有次膦酸酯供体片段。这些配体的几种新的过渡金属配合物通过光谱和X-射线结构分析进行了表征。
Synthesis of monohydroxy -methyl- and -ethyl-phosphines PPh2CHROH
作者:Guillermo Muller、Daniel Sainz
DOI:10.1016/0022-328x(95)05425-o
日期:1995.6
The preparation of alpha-hydroxyphosphines PPh(2)CHROH with R = H (a), Ph (b) and Et (c), and beta-hydroxyphosphines PPh(2)CHR'HROH (e-i) has been achieved in high yield by reaction of HPPh(2) or LiPPh(2) with RCHO or the oxides of cyclohexene (e), limonene (f), styrene (g, h) and pinene (i). With the exception of styrene oxide, the reactions with the oxides are very regioselective, giving only one of the possible isomers. Cis- and trans-limonene oxides react with LiPPh(2) in different conditions selectively, giving trans-phosphino derivatives from commercial mixtures of limonene oxide.