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1.
An efficient Pd(0)-catalyzed Buchwald-Hartwig protocol for the facile preparation of N-aryl and N-heteroaryl substituted homopiperazines is described. The syntheses proceeded with aryl- and heteroaryl halides in high yields using X-Phos as best ligand. The C-N coupling products were prepared both under conventional as well as microwave heating conditions and examples for microwave-assisted upscaling are included in this study. 相似文献
2.
Copper-Catalyzed Synthesis of Axially Chiral Biaryls with Diaryliodonium Salts as Arylation Reagents
NOBIN and BINAM derivatives harboring biaryl frameworks are recognized as a class of important atropisomers with versatile applications. Here, we present an efficient synthetic route to access such compounds through copper-catalyzed domino arylation of N-arylhydroxylamines or N-arylhydrazines with diaryliodonium salts and [3,3]-sigmatropic rearrangement. This reaction features mild conditions, good substrate compatibility, and excellent efficiency. The practicality of this protocol was further extended by the synthesis of biaryl amino alcohols. 相似文献
3.
Steven Fletcher 《Tetrahedron letters》2009,50(29):4258-84
A facile, efficient and mild synthesis of 2,6,9-tri-substituted purines is presented, starting from commercially available 2-amino-6-chloropurine, which employs sequential N9 then N2 Mitsunobu reactions as key steps. Importantly, our synthetic approach to N2-functionalization of the purine nucleus obviates the harsh conditions required by the traditional nucleophilic aromatic substitution of a 2-halo group with primary amines. Benzylic, allylic, propargylic and aliphatic alcohols all coupled in very good to excellent yields in both Mitsunobu reactions. Significantly, excellent chemoselectivity and N9-regioselectivity were observed for the first coupling, and reactions were complete within 15 min at room temperature. Our novel methodology may be readily adapted to furnish N9-mono- or N2,N9-di-functionalized guanine analogues, and the utility of our protocol is further demonstrated by the efficient synthesis of the CDK inhibitor bohemine. 相似文献
4.
Shane M. Devine 《Tetrahedron》2008,64(8):1772-1777
Herein we report an efficient synthesis of adenosine-5′-N-alkyluronamides in which an enzyme-mediated deacetylation reaction is a key to the selective modification of the 5′-N-position, prior to coupling the ribose and purine components via a microwave-assisted Vorbrüggen coupling. This approach provides access to highly functionalised adenosines with 2- and N6-substitutents, which can be incorporated before or after the ribose-coupling step. In all cases the microwave-assisted Vorbrüggen coupling conditions afforded anomerically pure purine ribosides in good to excellent yields. 相似文献
5.
Ganesh C. Nandi Sudhakar R. Kota Thavendran Govender Hendrik G. Kruger Per I. Arvidsson 《Tetrahedron》2014
We report a highly efficient and mild protocol for Chan–Evans–Lam C–N cross coupling of sulfonimidamides and aryl boronic acids using Cu(OAc)2 as mediator, triethylamine (TEA) as base and acetonitrile as solvent. The reaction proceeds at room temperature and provides high to excellent yields for a variety of boronic acids, allowing N-arylation of both N-protected (N-amine nitrogen) and N-deprotected (N′-imine nitrogen) sulfonimidamides. 相似文献
6.
Atef Mayooufi Moufida Romdhani-Younes Johan Jacquemin Jérôme Thibonnet 《Tetrahedron letters》2019,60(39):151087
A one‐pot sequence of Sonogashira coupling and iodocyclization afforded novel amino-containing trisubstituted 2H-pyran-2-ones in good yields. This transformation proceeds via 1) synthesis of an ynenoic ester intermediate by a Sonogashira coupling reaction with an N-substituted (Z)-3-iodovinylic ester; 2) intramolecular iodocyclization of the latter intermediate under mildly basic conditions. The flexibility of this strategy enables the efficient syntheses of a variety of substituted 2H-pyran-2-ones. 相似文献
7.
Biquan Xiong Gang Wang Tao Xiong Liming Wan Congshan Zhou Yu Liu Panliang Zhang Changan Yang Kewen Tang 《Tetrahedron letters》2018,59(32):3139-3142
The direct synthesis of N-arylamides via the coupling of aryl diazonium tetrafluoroborates and nitriles under transition-metal-free conditions has been developed. The reported protocol is practical and represents an efficient method to produce functionalized amides in moderate to good yields. 相似文献
8.
A mild and efficient Pd-catalyzed coupling of amides with 2-chloropyrimidines is described. The use of bidentate phosphines, such as Xantphos (7), as supporting ligands was found to be crucial for providing high yields of 2-(N-acylamino)pyrimidine coupling products 1. 相似文献
9.
Bret Tréguier 《Tetrahedron letters》2009,50(47):6549-6552
A quick and efficient entry to 1,1-diarylethylenes via the reaction of polyoxygenated aryl N-tosylhydrazones with aryl triflates is described. The reaction employs the catalytic system Pd(OAc)2/XPhos, tBuOLi as the base and dioxane as the solvent. A variety of substituents on both the coupling partners’ hydrazones and triflates are tolerated. This procedure provides a complementary route to the existing methods for the access to 1,1-diarylethylenes of biological interest. 相似文献
10.
11.
Rahman Hosseinzadeh Yaghoub Sarrafi Maryam Mohadjerani Fatemeh Mohammadpourmir 《Tetrahedron letters》2008,49(5):840-843
A mild and efficient method for the copper-catalyzed arylation of phenylurea is described. The coupling reaction of phenylurea with different functionalized aryl iodides in the presence of air stable CuI, N,N′-dibenzylethylenediamine as a ligand, and KF/Al2O3 as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields. 相似文献
12.
Naoki Kise Yosei Takenaga Yohei Ishikawa Yoichi Morikami Toshihiko Sakurai 《Tetrahedron letters》2012,53(15):1940-1945
The reductive coupling of N-methoxycarbonyl lactams with benzophenone by Zn-TiCl4 in THF gave cross-coupled products as cyclic α-diphenylidene-N-methoxycarbonylamines and ring-opening α,α-diphenyl-α-hydroxy-ω-(N-methoxycarbonyl)amino ketones selectively depending on the reduction conditions. The reductive coupling of N-methoxycarbonyl lactams with 9-fluorenone by Zn-TiCl4 gave cyclic α-(9H-fluoren-9-ylidene)-N-methoxycarbonylamines preferentially irrespective to the conditions. 相似文献
13.
A newly developed chemoselective reaction of sodium arylsulfinates or arylsulfonyl chlorides with nitroarenes has been disclosed. The chemistry, in which non-toxic water and recyclable iron-based metal-organic frameworks are employed as the solvent and catalyst, respectively, provides an efficient approach for the generation of N-arylsulfonamides, which are widely present in biologically active compounds and drugs, rendering this methodology attractive to both synthetic and medicinal chemistry. 相似文献
14.
Ralf Wischnat Joachim RudolphRoman Hanke Roger KaeseAchim May Heidi TheisUndine Zuther 《Tetrahedron letters》2003,44(23):4393-4394
An efficient scalable synthesis of 2-halothiazolium-type peptide coupling reagents has been developed. The key step is the formation of the 2-bromothiazole scaffold through cyclization of α-thiocyanato ketones with hydrogen bromide. Using this method, the new coupling reagent 2-bromo-N-methylthiazolium bromide (BMTB) was synthesized. BMTB was tested in a difficult model coupling reaction of two sterically hindered N-methylated amino acids and showed higher activity than the well-established peptide coupling reagent HATU. 相似文献
15.
Smita Rai 《Tetrahedron》2007,63(11):2455-2465
Three porphyrin building blocks with N4, N3S and N2S2 cores having three meso-furyl groups and one meso-iodophenyl group were synthesized and characterized. The porphyrin building blocks were used to synthesize six porphyrin dyads such as N4-N4, N3S-N3S, N2S2-N2S2, N4-N3S, N4-N2S2 and N3S-N2S2 containing meso-tolyl and meso-furyl porphyrin sub-units under mild Pd(0) mediated coupling conditions. Steady state fluorescence studies indicated an efficient energy transfer from the meso-tolyl porphyrin sub-unit to the meso-furyl porphyrin sub-unit in all six dyads. This study supported the argument that the meso-furyl porphyrins can be used as good energy acceptors when meso-aryl porphyrins act as energy donors in their metal free form. 相似文献
16.
2-Carbomethoxy-3-hydroxyquinoxaline-di-N-oxide was identified as an efficient novel ligand for the copper-catalyzed coupling reactions of aryl iodides, bromides, and chlorides with aliphatic amines and N-containing heterocycles under mild conditions. The catalytic system showed great functional-group tolerance and excellent chemoselectivity. 相似文献
17.
《Tetrahedron》2014,70(21):3385-3389
This work reported that Suzuki–Miyaura coupling reactions of arylboronic acid with aryl bromide or iodides were mediated by Pd(OAc)2 and 4-(benzylthio)-N,N,N-trimethylbenzenammonium chloride in the presence of Na2CO3 in water under the mild conditions. The corresponding Suzuki–Miyaura coupling products were obtained in good to excellent yields. 相似文献
18.
Mecheril V. Nandakumar 《Tetrahedron》2005,61(41):9775-9782
A Pd2dba3/P(i-BuNCH2CH2)3N catalyzed one-pot synthesis of unsymmetrically substituted trans-4-N,N-diarylaminostilbenes and both symmetrically and unsymmetrically substituted N,N-diarylaminostyrene derivatives is reported. The procedure involves two or more palladium catalyzed sequential coupling reactions (an amination and an inter-molecular Heck reaction) in one-pot using the same catalyst system with two different aryl halides, including aryl chlorides and hetero aryl halides as the coupling partners. 相似文献
19.
Facile one-pot synthesis of a novel all-carbon stair containing dimerized pentalene core from alkyne
Hui Zhao Rakesh Kumar Gupta Wei Zhang Jiong Jia Qun Yu Zhiyong Gao Guilin Zhuang Dacheng Li Xingpo Wang Chen Ho Tung Di Sun 《中国化学快报》2022,33(4):2047-2051
The construction of all-carbon molecule frameworks remains challenging. Herein, we report a facile and efficient one-pot synthesis of a novel all-carbon stair containing dimerized pentalene core using inexpensive cyclopropyl alkyne catalyzed by in situ generated Cu(I) from the comproportionation reaction of Cu(II) salt and Cu powder under mild reaction conditions. The reaction proceeds via sequential acetylenic coupling, followed by cyclization and [2 + 2] cycloaddition to directly produce penta... 相似文献
20.
Wen-Yi Wei Zi-Rong Gong Xin-Yue Chai Prof. Dr. Yan-Jun Xu Prof. Dr. Lin Dong 《European journal of organic chemistry》2023,26(19):e202300294
Rhodium(III)-catalyzed cross-dehydrogenative coupling involves a highly efficient C−C bond formation from N-phenyl-7-azaindole frameworks, thiophenes. Various novel 7-azaindole derivatives have been successfully developed with good substrate applicability. 相似文献