共查询到20条相似文献,搜索用时 15 毫秒
1.
Lingjuan Zhang Chaonan Dong Chenjun Ding Jing Chen Weijun Tang Huanrong Li Lijin Xu Jianliang Xiao 《Advanced Synthesis \u0026amp; Catalysis》2013,355(8):1570-1578
A general and convenient palladium‐catalyzed oxidative Heck arylation of both N‐protected and N,N‐diprotected allylic amines with arylboronic acids under mild conditions has been developed. The catalyst system, consisting of Pd(OAc)2 (palladium acetate), AgOAc (silver acetate) and KHF2 (potassium hydrogen fluoride), could efficiently catalyze the coupling reaction in acetone without the aid of any ligand, leading exclusively to the γ‐arylated allylic amine products in good to excellent yields. This method is highlighted with excellent regio‐ and stereocontrol and remarkable functional group tolerance. The carbamate moiety in allylic amine substrates is of crucial importance to the catalytic performance, and the chelation between the carbonyl O (oxygen) and Pd (palladium) atoms is believed to be responsible for the high regioselectivity and stereoselectivity observed. 相似文献
2.
Xiao‐Feng Wu Helfried Neumann Matthias Beller 《Advanced Synthesis \u0026amp; Catalysis》2011,353(5):788-792
A general palladium‐catalyzed carbonylative cross‐coupling reaction of benzyl chlorides with potassium aryltrifluoroborates in water has been developed. Applying this improved methodology 16 different 1,2‐diarylethanones have been synthesized in 40–89% yield. 相似文献
3.
Yang Chen Dong‐Mei Ma Fei‐Fei Ba Jing Sun Tian Liu Lei Zhu Ming‐Dong Zhou 《Advanced Synthesis \u0026amp; Catalysis》2016,358(17):2849-2854
The palladium(II)‐catalyzed hydroarylation of diphenylphosphorylallenes (via 1,2‐addition of the allenic double bond) with arylboronic acids in the presence of sodium hydroxide and oxygen is developed. The regioselectivities turn out to be well controlled, affording 2‐aryl‐3‐(diphenylphosphinyl)alkenes as the only product. Moreover, the stereoselectivities for reactions of γ‐substituted allenes can also be nicely controlled, resulting in the formation of Z‐alkenes. The reaction shows high substituent loading capability and tolerance of various substituents. A mechanism, including transmetalation of arylboronic acid with palladium halides, insertion of the 1,2‐allenic double bond to the Pd−Ar bond, and protonation to afford the final hydroarylation product is proposed.
4.
A palladium(II)‐catalyzed, one‐pot enantioselective synthesis of arylglycine derivatives from ethyl glyoxylate, p‐toluenesulfonyl isocyanate and arylboronic acids giving moderate to good yields and enantioselectivity has been developed. This reaction provides a convenient and efficient method for the synthesis of arylglycines. 相似文献
5.
LarissaB. Wolf KimC.M.F. Tjen HefzibaT. tenBrink RichardH. Blaauw Henk Hiemstra HansE. Schoemaker FlorisP.J.T. Rutjes 《Advanced Synthesis \u0026amp; Catalysis》2002,344(1):70-83
Enantiomerically pure acetylene‐containing α‐amino acids were used as versatile starting materials for the synthesis of a variety of heterocycles via Pd‐mediated cyclization reactions. Depending on the protecting group strategy, both the carboxylate and the amine function of the amino acids could participate in the cyclizations, thus giving rise to oxygen heterocycles (α‐aminolactones) and nitrogen heterocycles (cyclic α‐amino acid derivatives), respectively. Beside the straightforward cyclization, cyclization/cross‐coupling reactions were also successfully carried out to provide the corresponding substituted cyclic amino acid derivatives. 相似文献
6.
Jing‐Kun Xu Yong Wang Yonghong Gu Shi‐Kai Tian 《Advanced Synthesis \u0026amp; Catalysis》2016,358(11):1854-1858
An unprecedented stereospecific allylation reaction of nitroacetates with enantioenriched primary allylic amines has been developed. A range of nitroacetates smoothly underwent allylation with enantioenriched primary allylic amines in the presence of a palladium catalyst and boric acid followed by one‐pot decarboxylation to afford structurally diverse homoallylic nitro compounds in good to excellent yields with excellent retention of configuration. On the other hand, the allylation followed by denitronation provided a facile synthetic route to optically active β‐chiral γ,δ‐unsaturated esters.
7.
8.
Renshi Luo Ke Li Yuling Hu Wenjun Tang 《Advanced Synthesis \u0026amp; Catalysis》2013,355(7):1297-1302
A new C2‐symmetrical, chiral bisphosphorus ligand proved to be efficient for the rhodium‐catalyzed nucleophilic addition of arylboronic acids to trifluoromethyl ketones, providing a series of chiral trifluoromethyl‐substituted tertiary alcohols in high yields (up to 93%) and excellent enantioselectivities (>99%). 相似文献
9.
Oscar Pmies Montserrat Diguez Carmen Claver 《Advanced Synthesis \u0026amp; Catalysis》2007,349(6):836-840
We have designed a new family of readily available highly‐modular phosphite‐phosphoramidite ligands for asymmetric allylic alkylation reactions. The introduction of a phosphoramidite moiety in the ligand design is highly advantageous in the product outcome. Thus, this ligand series affords high reaction rates and enantioselectivities and, at the same time, shows a broad scope for disubstituted hindered and unhindered substrate types. 相似文献
10.
The use of tricyclohexylphosphine (and related phosphines) in palladium‐catalysed allylic substitution reactions enables the selective conversion of branched allylic acetates into the branched substitution products (up to 120:1 regioselectivity). Linear allylic acetates do not show the same selectivity for the branched substitution products, thereby demonstrating a memory effect. 相似文献
11.
The first copper‐catalyzed allylic substitution reactions of allylic acetates and carbamates employing a bis(triorganosilyl)zinc reagent are reported. This novel procedure avoids the use of stoichiometric amounts of copper salts which are usually mandatory with this chemistry. Application of this methodology to standard model substrates substantiates a high diastereoselectivity for the double bond geometry (E : Z) as well as the relative configuration (syn : anti). 相似文献
12.
Xiaoming Qu Peng Sun Tingyi Li Jincheng Mao 《Advanced Synthesis \u0026amp; Catalysis》2011,353(7):1061-1066
Highly effective palladium‐catalyzed Heck‐type couplings of hypervalent iodine reagents are reported for the first time. It is noteworthy that such reactions could be carried out in the absence of ligand at 40 °C and the catalytic system could be easily reused for five times. 相似文献
13.
Yuheng Deng Zhen Jiang Min Yao Dan Xu Lingjuan Zhang Huanrong Li Weijun Tang Lijin Xu 《Advanced Synthesis \u0026amp; Catalysis》2012,354(5):899-907
The highly efficient and regioselective palladium‐catalyzed Heck coupling of aryl bromides with electron‐rich allylamine derivatives is described. It was found that the choice of solvent, olefin, ligand and additive had a fundamental influence on the regioselectivity and reactivity of the reaction. The combination of palladium acetate [Pd(OAc)2] and 1,3‐bis(diphenylphosphino)propane (dppp) in ethylene glycol (EG) constitutes a highly effective catalyst system for internal arylation of N‐Boc‐allylamine (tert‐butyl methyl allyliminodicarbonate) with aryl bromides to give good to excellent regioselectivities, while the catalyst system consisting of Pd(OAc)2, tetrabutylammonium bromide (TBAB) and 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) additive allows for a variety of aryl bromides to react efficiently with N,N‐(Boc)2‐allylamine (di‐tert‐butyl allyliminodicarbonate) in water to exclusively afford the linear (E)‐allylamine products in high yields. 相似文献
14.
Tetsuhiro Nemoto Tomoyuki Nozaki Mariko Yoshida Yasumasa Hamada 《Advanced Synthesis \u0026amp; Catalysis》2013,355(13):2693-2700
A novel and efficient synthetic method for functionalized spiro[4.5]cyclohexadienones was developed based on the palladium‐catalyzed sequential process: Heck insertion to an allene–intramolecular ipso‐Friedel–Crafts allylic alkylation cascade. Using 5 mol% of palladium catalyst, a wide variety of spirocycles was obtained in good to excellent yields. The developed cascade process was also applicable to the synthesis of tetrahydronaphthalene derivatives.
15.
Wen‐Bo Chen Chun‐Hui Xing Jie Dong Qiao‐Sheng Hu 《Advanced Synthesis \u0026amp; Catalysis》2016,358(13):2072-2076
The use of electron‐poor, fluoro‐containing arylboronic acids as general coupling partners for nickel(0)/tricyclohexylphosphine‐catalyzed cross‐coupling of aryl arenesulfonates is described. Electron‐poor fluoro‐containing arylboronic acids were found to react faster than electron‐rich/neutral arylboronic acids, with (4‐methoxyphenyl)(4‐methylbenzenesulfonato‐κO)bis(tricyclohexylphosphine)nickel. Bis(1,5‐cyclooctadiene)nickel(0)/tricyclohexylphosphine, (4‐methoxyphenyl)(4‐methylbenzenesulfonato‐κO)bis(tricyclohexylphosphine)nickel and bis(tricyclohexylphosphine)nickel(II) bromide were all found to be efficient catalysts/catalyst precursors.
16.
Yvette Mata Montserrat Diguez Oscar Pmies Carmen Claver 《Advanced Synthesis \u0026amp; Catalysis》2005,347(15):1943-1947
We have designed and synthesized a new family of readily available phosphite‐oxazoline ligands for Pd‐catalyzed asymmetric allylic substitution reactions. These ligands can be tuned in two regions to explore their effect on catalytic performance. By carefully selecting the ligand components, we obtained high enantioselectivities in the Pd‐catalyzed allylic substitution in substrates with different steric properties 相似文献
17.
Miwako Mori Toyoki Nishimata Yuji Nagasawa Yoshihiro Sato 《Advanced Synthesis \u0026amp; Catalysis》2001,343(1):34-36
Vinyl carbonate was found to be a very effective leaving group in palladium‐catalyzed allylic substitution. When the reaction of an equimolar amount of allyl methyl carbonate and allyl vinyl carbonate with dimethyl malonate was carried out in the presence of a palladium catalyst, allyl vinyl carbonate reacted with the nucleophile, and most of allyl methyl carbonate remained unchanged. In the reaction of a compound having allyl methyl carbonate and allyl vinyl carbonate in the molecule with tosyl amide, in the presence of a palladium catalyst, the nucleophile reacted with the allyl vinyl carbonate, and the allyl methyl carbonate remained unchanged. 相似文献
18.
Xiang‐Min Sun Masatoshi Koizumi Kei Manabe Sh Kobayashi 《Advanced Synthesis \u0026amp; Catalysis》2005,347(15):1893-1898
New types of P,N‐ligands, cis‐ and trans‐ 3 , containing a tetrahydroisoquinoline skeleton as an N‐donor were synthesized from (1R,2S)‐1‐phenylphospholane‐2‐carboxylic acid (phenyl‐P‐proline, 1 ). The cis isomer, cis‐ 3 , was found to act as an excellent ligand in palladium‐catalyzed asymmetric allylic substitution reactions. The reactions of 1,3‐diphenyl‐2‐propenyl acetate ( 5 ) with several nucleophiles in the presence of [Pd(π‐allyl)Cl]2, cis‐ 3 (Pd : ligand=1 : 2), and a base afforded the desired products in high yields with high enantioselectivity. It was suggested that these ligands did not serve as P,N‐bidentate ligands but as P‐monodentate ligands in these reactions. 相似文献
19.
Giuliana Cardillo Serena Fabbroni Luca Gentilucci Rossana Perciaccante Alessandra Tolomelli 《Advanced Synthesis \u0026amp; Catalysis》2005,347(6):833-838
The palladium‐catalyzed benzylamine attack to a particular allylic moiety, the 3‐alkenyl‐3‐bromoazetidin‐2‐one is herein reported. This reaction shows interesting mechanistic aspects and allows us to introduce in one step and under high regio‐ and stereocontrol the amino function in the C3 side chain of non‐conventional β‐lactams, thus offering the opportunity for designing new potential glutamine syntethase inhibitors, such as Tabtoxin analogues. 相似文献
20.
Carbon‐selenium and carbon‐tellurium cross‐couplings of arylboronic acids with diselenides and ditellurides have been catalyzed by iron(0), iron(II) chloride or iron(III) chloride without any ligand and additive in the air. The method yields the corresponding unsymmetrical diorgano monoselenides and monotellurides in good to excellent yields, displays a broad substrate scope, and is simple, convenient, effective, economical and environmentally friendly. 相似文献