二氧化硅负载聚-γ-(二苯胂基)丙基硅氧烷钯(0)配合物的合成与催化卤代芳烃的偶联反应

聚 γ 氯丙基硅氧烷依次与二苯胂钾、氯化钯作用 ,再经水合肼还原 ,合成了二氧化硅负载的聚 γ (二苯胂基 )丙基硅氧烷钯 (0 )配合物 .该钯 (0 )配合物可有效地催化芳基卤化物与烯烃、炔烃、Grignard试剂之间的交叉偶联反应 ,并且可以回收再用多次 ,其活性基本保持不变 .     

Synthesis of 3-substituted 4-aroylisoquinolines via Pd-catalyzed carbonylative cyclization of 2-(1-alkynyl)benzaldimines

A number of 3-substituted 4-aroylisoquinolines have been prepared in good yields by treating N-tert-butyl-2-(1-alkynyl)benzaldimines with aryl halides in the presence of CO and a palladium catalyst. Synthetically the methodology provides a simple and convenient route to isoquinolines containing an aryl, alkyl, or vinylic group at C-3 and an aroyl group at C-4 of the isoquinoline ring. The reaction is believed to proceed via cyclization of the alkyne containing a proximate nucleophilic center promoted by an acylpalladium complex.     

Synthesis of 2-alkylidenecyclopentanones via palladium-catalyzed carbopalladation/ring expansion of 1-(1-alkynyl)cyclobutanols

The palladium-catalyzed cross-coupling of aryl halides or vinylic halides or triflates and 1-(1-alkynyl)cyclobutanols affords good yields of stereoisomerically pure 2-arylidene- or 2-(2-alkenylidene)cyclopentanones, respectively. The process involves (1) oxidative addition of the organic halide or triflate to Pd(0), (2) regioselective, intermolecular carbopalladation of the carbon-carbon triple bond of the 1-(1-alkynyl)cyclobutanol to produce a vinylic palladium intermediate, (3) regioselective ring expansion to a palladacycle, and (4) reductive elimination of the 2-alkylidenecyclopentanone with simultaneous regeneration of the Pd(0) catalyst. Generally, the best results are obtained by employing 10 mol % of Pd(OAc)(2), 20 mol % of PPh(3), 2 equiv of the aryl or vinylic iodide or vinylic triflate, 2 equiv of diisopropylethylamine, and n-Bu(4)NCl in DMF as the solvent.     

Copper(I) tert-butoxide-promoted 1,4 C sp 2-to-O silyl migration: generation of vinyl copper equivalents and their stereospecific cross-coupling with allylic,aryl, and vinylic halides

Successive treatment of the (Z)-gamma-trimethylsilyl allylic alcohols with copper(I) tert-butoxide and allylic halides followed by the tetrabutylammonium fluoride-assisted hydrolysis produced the allylation products, 2,5-alkadien-1-ols, with complete retention of configuration. Similar treatment of the organometallic intermediates with aryl and vinylic halides in the presence of palladium(0) catalyst gave the corresponding cross-coupling products in good yields. The stereoselective preparation of the starting materials is also described.     

二氧化硅负载的胂钯(0)配合物作为丙烯酸丁酯和丙烯酰胺芳基化反应高活性和高立体选择性的催化剂

A silica-supported arsine palladium(O) complex has been prepared from y-chloropropyltriethoxysilane via immobilization on fumed silica, followed by reaction with potassium diphenylarsenide and palladium chloride, and then reduction with hydrazine hydrate. The complex has been characterized by X-ray photoelectron spectroscopy (XPS) and it is a highly active and stereoselective catalyst for arylation of butyl acrylate and acrylamide with aryl halides, affording a variety of tram-butyl cinnamates and trans-cinnamamides in high yields.     

二氧化硅负载的聚-4-硫杂-6-二苯膦己基硅氧烷钯(0)配合物的合成与催化性能

聚-4-硫杂-6-二苯膦己基硅氧烷与氯化钯作用后经水合肼还原,合成了二氧化硅负载的硫-膦混合双齿钯(0)配合物.该配合物可以有效地催化芳(烯)基卤化物与烯烃、炔烃、Grignard试剂的交叉偶联反应,并可回收多次利用,活性基本不变.     

MCM-41负载硫醚钯配合物的合成及其催化芳基卤化物的羰基化性能

γ-(β-氰乙硫基)丙基三乙氧基硅烷依次用纳米介孔分子筛(MCM-41)固载、与氯化钯反应, 合成了MCM-41负载硫醚钯配合物. 该新型负载钯配合物是芳基卤化物的羰基化反应的有效催化剂, 为各种取代的N-苯基苯甲酰胺、苯甲酸丁酯的合成提供了方便实用的新途径.     

新型含氮三齿钯(II)配合物的合成及其催化性能研究

以白屈氨酸为原料, 经酯化、还原、溴化、胺化等反应合成了4位带活性基团的新型含氮(NN'N)三齿配体, 配体进一步与氯化钯反应制得了Pd(II)的配合物, 并用红外、核磁、元素分析等手段进行了表征. 考察了这种钳形配合物的催化性能, 结果表明该配合物对卤代苯与乙烯基化合物的Heck芳基化反应具有较高的催化活性.     

有机硅聚合物负载双齿硒钯配合物的合成与催化性能

4 氧杂 6 ,7 二氯庚基三甲氧基硅烷依次与气相法二氧化硅、甲硒基钠、氯化钯作用 ,合成了二氧化硅固载的聚 4 氧杂 6 ,7 二甲硒基庚基硅氧烷钯配合物 .它对芳基卤化物的Heck羰基化反应具有良好的催化活性 .     

Novel palladium nanoparticles supported on β‐cyclodextrin@graphene oxide as magnetically recyclable catalyst for Suzuki–Miyaura cross‐coupling reaction with two different approaches in bio‐based solvents

A novel nanocatalyst was designed and prepared. Initially, the surface of magnetic graphene oxide (M‐GO) was modified using thionyl chloride, tris(hydroxymethyl)aminomethane and acryloyl chloride as linkers which provide reactive C═C bonds for the polymerization of vinylic monomers. Separately, β‐cyclodextrin (β‐CD) was treated with acryloyl chloride to provide a modified β‐CD. Then, in the presence methylenebisacrylamide as a cross‐linker, monomers of modified β‐CD and acrylamide were polymerized on the surface of the pre‐prepared M‐GO. Finally, palladium acetate and sodium borohydride were added to this composite to afford supported palladium nanoparticles. This fabricated nanocomposite was fully characterized using various techniques. The efficiency of this easily separable and reusable heterogeneous catalyst was successfully examined in Suzuki–Miyaura cross‐coupling reactions of aryl halides and boronic acid as well as in modified Suzuki–Miyaura cross‐coupling reactions of N‐acylsuccinimides and boronic acid in green media. The results showed that the nanocatalyst was efficient in coupling reactions for direct formation of the corresponding biphenyl as well as benzophenone derivatives in green media based on bio‐based solvents. In addition, the nanocatalyst was easily separable, using an external magnet, and could be reused several times without significant loss of activity under the optimum reaction conditions.     

聚-4-氧杂-6,7-二甲硒基庚基硅氧烷钯(0)配合物的合成及其催化性能研究

4 氧杂 6,7 二氯庚基三甲氧基硅烷依次与气相法二氧化硅、甲硒基钠、氯化钯作用 ,然后用水合肼还原 ,合成了二氧化硅负载的聚 4 氧杂 6,7 二甲硒基庚基硅氧烷钯 ( 0 )配合物 .该配合物是苯乙烯及丙烯酸的Heck芳基化反应的有效催化剂 ,为立体选择性地合成各种取代的反式 1,2 二苯乙烯及反式肉桂酸提供了简便且实用的新方法 .     

Control of regioselectivity in Pd(0)-catalyzed coupling-cyclization reaction of 2-(2',3'-allenyl)malonates with organic halides

The regioselectivity in the Pd(0)-catalyzed coupling-cyclization of 2-(2',3'-allenyl)malonates with organic halides is determined by the steric and electronic effects of both substrates. By deliberate control of the reaction conditions, the regioselectivity of this reaction can be tuned. With conditions A and B, the reaction afforded vinylic cyclopropane derivatives, while with conditions C and D, the reaction afforded cyclopentene derivatives in a highly selective manner. Under similar conditions, 1-alkenyl halides tend to form more three-membered cyclic products. The increased steric hindrance at the 2'-position of the allene moiety and aryl halides favors the formation of five-membered cyclic products. The regioselectivity of the reaction may be explained by the comparison of the relative stabilities of syn- and anti-type pi-allyl palladium intermediates.     

A silica-supported palladium-bis(oxazoline) complex efficiently catalyzes the synthesis of cinnamic acid derivatives via Mizoroki–Heck coupling reactions

A palladium(II)-bis(oxazoline) complex supported on silica (Pd-BOX-Si) was prepared, characterized and applied as a catalyst in Mizoroki–Heck cross-coupling reactions. The bis(oxazoline) (BOX) ligand has a hydroxyl group that can be anchored to 4-benzyl chloride-functionalized silica gel, followed by the coordination of palladium(II) chloride. The catalytic activity and the recyclability of Pd-BOX-Si have been investigated in the production of cinnamic acid derivatives via Mizoroki–Heck coupling reactions of acrylates with aryl halides; The Pd-BOX-Si catalyst demonstrated excellent catalytic activity. Characterization of the recycled Pd-BOX-Si catalyst revealed its good stability under the reaction conditions employed.     

Convenient Method for Dehalogenation of Aryl Halides

Reductive dehalogenation of aryl halides was achieved using hydrogen and a palladium catalyst. By using deuterium gas, the deuterated arenes were readily prepared.     

Synthesis of 9-alkylidene-9H-fluorenes by a novel, palladium-catalyzed cascade reaction of aryl halides and 1-aryl-1-alkynes.

In the presence of a palladium catalyst and NaOAc, aryl iodides react with 1-aryl-1-alkynes to afford 9-alkylidene-9H-fluorenes in good yields. The products from this reaction are highly dependent on the base employed. This process appears to involve (1) oxidative addition of the aryl iodide to Pd(0), (2) alkyne insertion, (3) rearrangement of the resulting vinylic palladium intermediate to an arylpalladium species, and (4) aryl-aryl coupling with simultaneous regeneration of the Pd(0) catalyst. Consistent with this mechanism is the fact that 9-alkylidene-9H-fluorenes can also be prepared by the Pd-catalyzed rearrangement of 1,1-diaryl-2-iodo-1-alkenes.     

Palladium‐Catalyzed Chlorocarbonylation of Aryl (Pseudo)Halides Through In Situ Generation of Carbon Monoxide

An efficient palladium‐catalyzed chlorocarbonylation of aryl (pseudo)halides that gives access to a wide range of carboxylic acid derivatives has been developed. The use of butyryl chloride as a combined CO and Cl source eludes the need for toxic, gaseous carbon monoxide, thus facilitating the synthesis of high‐value products from readily available aryl (pseudo)halides. The combination of palladium(0), Xantphos, and an amine base is essential to promote this broadly applicable catalytic reaction. Overall, this reaction provides access to a great variety of carbonyl‐containing products through in situ transformation of the generated aroyl chloride. Combined experimental and computational studies support a reaction mechanism involving in situ generation of CO.     

Palladium-catalyzed oxidative carbonylation of alkyl and aryl indium reagents with CO under mild conditions

CO now can react with organoindium reagents. A novel palladium-catalyzed oxidative carbonylation reaction of organoindium reagents by CO gas with desyl chloride as oxidant was developed in supplementation with the classical methods for preparation of carboxylic acid derivatives. Primary, secondary alkyl indium reagents with beta-hydrogens and aryl indium reagents were suitable substrates, and the reaction could be carried out at 60 degrees C under 50 psi CO. Carbonylation of alkyl indium reagents can occur smoothly without additional base. Although the indium reagents were prepared from corresponding Grignard reagents (at low temperature), they displayed full compatibility with various functional groups under the protic reaction conditions. Preliminary mechanistic studies including stoichiometric and catalytic reaction examination provided evidence to support the operation of the mechanism consisted of oxidative addition of deslyl chloride to Pd(0) and quick tautomerization to give a palladium enolate species II (ROPdCl), displacement of the enolate group in II by R(2)OH, followed by CO insertion to give alkoxycarbonyl palladium complex V, which undergoes transmetalation with R(1)(3)In and reductive elimination to afford the product and a Pd(0) species. In this mechanism, the alkoxycarbonyl group was transferred to the palladium center prior to the alkyl group, different from traditional ways initiated from oxidative addition of alkyl halides to a Pd(0) species.     

二氧化硅负载胂钯(0)配合物催化酰氯和芳基碘与四苯硼化钠的苯基化反应

氯丙基三乙氧基硅烷依次与气相法二氧化硅、二苯胂钾、氯化钯作用, 再用水合肼还原, 合成了二氧化硅负载的胂钯(0)配合物. 该配合物是酰氯及芳基碘化物与四苯硼化钠苯基化反应的有效催化剂, 为苯基酮及不对称联苯的合成提供了简便且实用的新方法.     

Microwave-assisted Suzuki reaction catalyzed by Pd(0)-PVP nanoparticles

Suzuki cross-coupling reaction was successfully carried out in ethanol utilizing a palladium colloidal solution stabilized by polyvinylpyrrolidone (PVP). High isolated yields (75-97%) to biaryls were obtained using different bases, aryl halides, and aryl boronic acids with a small loading of the palladium catalyst. Pd(0)-PVP nanoparticles with 3-6 nm of medium diameter were prepared from Pd(OAc)₂ in the presence of the stabilizer PVP using methanol as the reducing agent.     

Synthesis of highly substituted 1,3-dienes, 1,3,5-trienes, and 3,6-disubstituted cyclohexenes by the palladium-catalyzed coupling of organic halides, internal alkynes or 1,3-cyclohexadienes, and organoboranes

A number of highly substituted 1,3-dienes and 1,3,5-trienes have been stereoselectively prepared in moderate to good yields by the coupling of vinylic iodides, internal alkynes, and organoboranes in the presence of a palladium catalyst. Optimal reaction conditions for different organoboron substrates have been developed. The analogous three-component coupling of aryl halides, 1,3-cyclohexadiene, and boronic acids provides a synthetically useful route to 3,6-disubstituted cyclohexenes. These methods are very efficient and provide an expeditious way to synthesize the indicated alkenes, dienes, and trienes, whose preparation would normally require multi-step synthesis.