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1.
非离子水溶性膦配体的合成及其应用进展   总被引:1,自引:0,他引:1  
按非离子水溶性膦配体的发展特点,就羟基取代膦配体、天然碳水化合物为母体的膦配体、聚醚基取代的膦配体、具手性中心的膦配体、高分子负载型膦配体、温控相转移膦配体、环糊精改性的膦配体等类型的非离子水溶性膦配体的合成及其在两相催化中的应用作一综述。  相似文献   

2.
A mild and efficient method for the synthesis of tertiary phosphines and ditertiary phosphines has been developed. In the presence of cesium hydroxide, molecular sieves and DMF at room temperature, various secondary phosphines and alkyl bromides were examined, and the results have demonstrated that this methodology offers a general synthetic procedure to produce tertiary phosphines in moderate to high yields. Optically active tertiary phosphine synthesis is also described.  相似文献   

3.
Jia-Ning Li  Lei Liu  Qing-Xiang Guo 《Tetrahedron》2006,62(50):11801-11813
Amines and phosphines are widely utilized as bases and basic organocatalysts in organic chemistry. Thus it is highly valuable to develop a coherent theoretical method that can accurately predict the basicity of structurally unrelated amines and phosphines in organic solvents from the first principles. Herein we developed the first ab initio protocol that could predict the pKa value of any protonated amine or phosphine in acetonitrile through systematic benchmarking. By comparing to a variety of available experimental data (total number=98), it was determined that the precision of the optimized method in basicity prediction was as low as 1.1 pKa unit. With the powerful new method in hand, we subsequently conducted some systematic studies about the basicity of organic amines and in particular phosphines, for which very few experimental data were available. It was found that the solvent exerted profound effects on the basicity of amines and phosphines. Accordingly we concluded that it was not valid to use gas-phase data to interpret the solution-phase basicity of amines and phosphines. Next we reported the basicity of a number of synthetically important aliphatic and aromatic amines and phosphines in acetonitrile. We also compared, for the first time, the α-substituent effects on the basicity of aliphatic amines and phosphines and the remote substituent effects on the basicity of aromatic amines and phosphines. Finally, we studied for the first time the basicity of cyclic amines and phosphines. It was found that the ring strain exerted some interesting effects on the basicity of amines and phosphines.  相似文献   

4.
Primary and secondary phosphines add regio- and stereospecifically to phenylcyanoacetylene and 4-hydroxy-4-methylpent-2-ynenitrile under mild conditions to form corresponding functionalized secondary and tertiary phosphines of Z-configuration in 70-91% yield. According to ESR and UV data, the addition of primary phosphines to phenylcyanoacetylene involves a single electron transfer process.  相似文献   

5.
Trialkyl and triaryl phosphines are important classes of ligands in the field of catalysis and materials research. The wide usability of these low-valent phosphines has led to the design and development of new synthesis routes for a variety of phosphines. In the present work, we report the synthesis and characterization of some mixed arylalkyl tertiary phosphines via the Grignard approach. A new asymmetric phosphine is characterized extensively by multi-spectroscopic techniques. IR and UV–Vis spectra of some selected compounds are also compared and discussed. Density functional theory (DFT)-calculated results support the formation of the new compounds.  相似文献   

6.
This research has demonstrated the utility of a rigorously calibrated, molecular mechanics/semiempirical quantum mechanical protocol for developing stereoelectronic (Tolman) maps for phosphine ligands. A computational analysis of alkyl and aryl phosphines in common usage suggests that these ligands are quite similar stereoelectronically. A noticeable gap in the Tolman map for common phosphines is observed for large, electron-poor phosphines. Several candidates meeting these criteria were identified, the most promising of which is P(t-C(4)F(9))(3). Phosphines in which the phosphorus participates in a ring, which comprise a very small subset of reported phosphines, have very interesting stereoelectronic properties, particularly those in which the ligating phosphorus is part of a three-membered ring. In terms of steric properties, the symmetric deformation coordinate proposed by Orpen and co-workers on the basis of crystallographic studies is calculated with sufficient accuracy using PM3(tm) to allow good confidence in predictions of novel phosphines. For quantification of the electronic properties of phosphines, we analyzed changes in the CO stretching frequency upon changing the ancillary phosphine ligands.  相似文献   

7.
The chiral Pt catalyst precursor Pt((R,R)-Me-Duphos)(Ph)(Cl) mediated alkylation of racemic secondary phosphines PHR(R') with benzyl halides in the presence of base to give enantioenriched tertiary phosphines PR(R')(CH2Ar). Similar reactions of bis(secondary) phosphines yielded chiral diphosphines in up to 93% ee and with good rac/meso diastereoselection.  相似文献   

8.
Carbohydrate-substituted phosphines are easily obtained in quite good yields by coupling of protected or non-protected d-glucosamine with the corresponding diphenylphosphino acid. These neutral ligands, in association with palladium acetate, are very active catalysts in the Suzuki cross-coupling reaction. The polyhydroxy phosphines are more active than the peracetylated phosphines. The process tolerates electron-rich as well as electron-poor substituents. Excellent turnovers, up to 97?000 are observed.  相似文献   

9.
Ruthenium phosphido complexes have been shown to be excellent nucleophiles, reacting via two-electron processes with a variety of electrophiles. A catalytic alkylation reaction was developed using an achiral ruthenium complex, which was then elaborated into a catalytic enantioselective synthesis of P-stereogenic phosphines. These useful and synthetically challenging phosphines can now be accessed in a single step from simple secondary phosphines and alkyl halides. Optimization and scope of the enantioselective alkylation are discussed.  相似文献   

10.
Anionic, electron-releasing phosphines that incorporate a borate counteranion within the ligand framework are promising reagents for organometallic catalysis. This report describes the synthesis of a new class of monodentate tertiary phosphines built upon the commonly employed tetraphenylborate anion. These new phosphines are highly stable and strongly electron-releasing and readily coordinate transition metals. Moreover, they are promising reagents for catalysis, as demonstrated by their ability to promote the Suzuki cross-coupling of aryl chloride substrates.  相似文献   

11.
Dendrimers are hyperbranched macromolecules, which are synthesized step-by-step by the repetition of a series of reactions. While many different types of dendrimers are known, this review focusses on the use of trivalent phosphorus derivatives (essentially phosphines and phosphoramidites) for the synthesis of dendrimers. The first part presents dendrimers constituted of phosphines at each branching point. The other parts display the use of trivalent phosphorus derivatives during the synthesis of dendrimers. Different types of reactions have been applied to phosphines. The very first examples of phosphorus-containing dendrimers were obtained by the alkylation of phosphines. Then, several families of dendrimers were elaborated by reaction of phosphoramidites. Such a type of reaction is the base of the solid phase synthesis of oligonucleotides; it has been applied in particular for the synthesis of dendrimers constituted of oligonucleotides. Finally, the Staudinger reaction between phosphines and azides afforded different families of dendrimers, and was at the origin of accelerated methods of synthesis of dendrimers. Besides, the reactivity of the P=N-P=S linkages created by this reaction led to very original dendritic structures.  相似文献   

12.
The visible-light-induced arylation of tertiary phosphines with aryl(mesityl)iodonium triflates to produce the quaternary phosphonium salts occurs under mild, metal, and catalyst-free conditions. Photo-excited EDA complexes between diaryliodonium salts and phosphines supposedly enable this transformation, which is difficult to achieve through the traditional ground-state reactions. Demonstrating high functional group tolerance, broad scope, and complete selectivity of the aryl group transfer, the method is particularly compatible with sterically congested phosphines, which are challenging under metal-based catalytic methods.  相似文献   

13.
A highly reactive and stereoselective hydrophosphination of enones catalyzed by palladacycles for the synthesis of C*- and P*-chiral tertiary phosphines has been developed. When Ph(2)PH was employed as the hydrophosphinating reagent, a series of C*-chiral tertiary phosphines were synthesized (C*-P bond formation) in high yields with excellent enantioselectivities, and a single recrystallization provides access to their enantiomerically pure forms. When racemic secondary phosphines rac-R(3)(R(4))PH were utilized, a series of tertiary phosphines containing both C*- and P*-chiral centers were generated (C*-P* bond formation) in high yields with good diastereo- and enantioselectivities. The stereoelectronic factors involved in the catalytic cycle have been revealed.  相似文献   

14.
手性膦配体的设计及不对称催化氢化反应   总被引:2,自引:0,他引:2  
本文综述了手性膦配体及其碳碳双键的不对称催化氢化反应研究和最新进展,并对手性膦配体的设计做了分析和总结。  相似文献   

15.
Phosphines are important ligands in homogenous catalysis and have been crucial for many advances, such as in cross‐coupling, hydrofunctionalization, or hydrogenation reactions. Herein we report the synthesis and application of a novel class of phosphines bearing ylide substituents. These phosphines are easily accessible via different synthetic routes from commercially available starting materials. Owing to the extra donation from the ylide group to the phosphorus center the ligands are unusually electron‐rich and can thus function as strong electron donors. The donor capacity surpasses that of commonly used phosphines and carbenes and can easily be tuned by changing the substitution pattern at the ylidic carbon atom. The huge potential of ylide‐functionalized phosphines in catalysis is demonstrated by their use in gold catalysis. Excellent performance at low catalyst loadings under mild reaction conditions is thus seen in different types of transformations.  相似文献   

16.
Ultra-branched mixed tetradentate tripodal phosphines and phosphine chalcogenides have been synthesized by the exhaustive regioselective addition of secondary phosphines, phosphine sulfides and phosphine selenides to available tris(4-vinylbenzyl)phosphine oxide under free-radical conditions (UV irradiation or AIBN) in good to excellent yields.  相似文献   

17.
Ambiphilic molecules, which contain a Lewis base and Lewis acid, are of great interest based on their unique ability to activate small molecules. Phosphine boronates are one class of these substrates that have interesting catalytic activity. Direct access to these phosphine boronates is described through the iridium‐catalyzed C?H borylation of phosphines. An unconventional cationic iridium catalyst was identified as optimal for a range of phosphines, providing good yields and selectivity across a diverse class of phosphine boronates (isolated as the borane‐protected phosphine). A complimentary catalyst system (quinoline‐based silane ligand with [(COD)IrOMe]2) was optimal for biphenyl‐based phosphines. Selective polyborylation was also shown providing bis‐ and tris‐borylated phosphines. Deprotection of the phosphine boronate provided free ambiphilic phosphine boronates, which do not have detectable interactions between the phosphorus and boron atoms in solution or the solid state.  相似文献   

18.
2-Organylseleno(telluro)ethyl phosphines and 4-organylthio(seleno (telluro))butyl phosphines were prepared by reduction of diethyl 2-organylseleno(telluro)ethyl phosphonates and diethyl 4-organylthio(seleno(telluro)) butyl phosphonates with lithium aluminium hydride in diethyl ether. 1H and 31P NMR spectra as well as mass spectra of the resulting phosphines were considered. Their stability in regard to the oxidation by oxygen was discussed.  相似文献   

19.
Shunpei Ishikawa 《Tetrahedron》2010,66(1):297-10163
Hydroxylated oligoarene-type phosphines with various substitution patterns were synthesized. Such phosphines have potential as ligands for transition metal-catalyzed reactions. A successful route, which includes a repetitive Suzuki-Miyaura coupling-triflation sequence, reduction, and salt formation, was established starting from 2-bromophenyldicyclohexylphosphine oxide. Other key aspects of the method are the use of suitable triflation reagents and the formation of phosphines as HBF4 salts. Interesting information was obtained from careful analysis of the byproducts in the triflation and reduction steps, and the mechanisms for their formation were proposed.  相似文献   

20.
Abstract

Alkyl- or arylbis(trimethylsilyl)phosphines as well as tris(trimethylsilyl)phosphine and the corresponding arsines react with acyl chlorides to give [1-(trimethylsiloxy)alkylidene]phosphines 1 and -arsines 2; most of their 2,2-dimethylpropylidene derivatives are thermally stable at room temperature. With the same class of phosphines as starting compounds and carbon disulfide [bis(trimethylsilylsulfano)methylidene]phosphines 3 are formed, whereas [(dialkylamino)methylidene]-4 and [diarylmethylidene]phosphines 5 or the corresponding arsines 6 and 7 can be obtained from acyl amides or ketones.1  相似文献   

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