29778-26-5Relevant articles and documents
Ligand-free (: Z)-selective transfer semihydrogenation of alkynes catalyzed by in situ generated oxidizable copper nanoparticles
Grela, Karol,Kusy, Rafa?
supporting information, p. 5494 - 5502 (2021/08/16)
Herein, we present (Z)-selective transfer semihydrogenation of alkynes based on in situ generated CuNPs in the presence of hydrogen donors, such as ammonia-borane and a green protic solvent. This environmentally friendly method is characterized by operational simplicity combined with high stereo- and chemoselectivity and functional group compatibility. Auto-oxidation of CuNPs after the completion of a semihydrogenation reaction results in the formation of a water-soluble ammonia complex, so that the catalyst may be reused several times by simple phase-separation with no need for any special regeneration processes. Formed NH4B(OR)4 can be easily transformed back into ammonia-borane or into boric acid. In addition, a one-pot tandem sequence involving a Suzuki reaction followed by semihydrogenation was presented, which allows minimization of chemical waste production.
Selective Phosphoranation of Unactivated Alkynes with Phosphonium Cation to Achieve Isoquinoline Synthesis
Cui, Hong,Bai, Jinku,Ai, Tianyu,Zhan, Ye,Li, Guanzhong,Rao, Honghua
supporting information, p. 4023 - 4028 (2021/05/26)
We herein develop a selective phosphoranation of alkynes with phosphonium cation, which directs a concise approach to isoquinolines from unactivated alkyne and nitrile feedstocks in a single step. Mechanistic studies suggest that the annulation reaction is initiated by the unprecedented phosphoranation of alkynes, thus representing a unique reaction pattern of phosphonium salts and distinguishing it from existing protocols that largely rely on the utilization of highly functionalized imines/oximes and/or highly polarized alkynes.
Highly efficient synthesis of 1,2-disubstituted acetylenes derivatives from the cross-coupling reactions of 1-bromoalkynes with organotitanium reagents
Li, Qing-Han,Wu, Chuan
supporting information, (2021/08/25)
A Highly efficient route for the synthesis of 1,2-disubstituted acetylene derivatives has been developed by nickel catalyzed cross-couplings of alkynyl halides with aryl titanium reagents under mild conditions. This has given corresponding cross-coupling products good to excellent isolated yields of up to 92 %. The aryls bearing electron-donating or electron-withdrawing groups in either alkynylhalides or aryltitanium substrates gave cross-coupling products good yields. This process was simple and easily performed, which provides an efficient method for the synthesis of 1,2-disubstituted acetylenes derivatives.
Glycosyl Triazole Ligand for Temperature-Dependent Competitive Reactions of Cu-Catalyzed Sonogashira Coupling and Glaser Coupling
Mishra, Nidhi,Singh, Sumit K.,Singh, Anoop S.,Agrahari, Anand K.,Tiwari, Vinod K.
, p. 17884 - 17895 (2021/12/17)
Glycosyl triazoles have been introduced as efficient ligands for the Cu-catalyzed Sonogashira reaction to overcome the challenges of sideways homocoupling reactions in Cu catalysis in this reaction. The atmospheric oxygen in a sealed tube did not affect t
Synthesis of Unprotected and Highly Substituted Indoles by the Ruthenium(II)-Catalyzed Reaction of Phenyl Isocyanates with Diaryl/Diheteroaryl Alkynes/Ethyl-3-phenyl Propiolates
Kumar, Amrendra,Tadigoppula, Narender
supporting information, p. 8 - 12 (2021/01/13)
A one-pot transformation has been developed for the synthesis of unprotected and highly substituted indoles by an in situ installed carbamide-directed Ru(II)-catalyzed intermolecular oxidative annulation of phenyl isocyanates with diaryl/diheteroaryl alkynes/ethyl phenyl propiolates in the presence of Cu(OAc)2·H2O as an oxidant and AgSbF6 as an additive at 120 °C within 3 h.
Palladium(II)-Catalyzed Oxidative Decarboxylative [2 + 2 + 1] Annulation of Cinnamic Acids with Alkynes: Access to Polysubstituted Pentafulvenes
Peng, Shiyong,Chen, Nuan,Zhang, Hong,He, Min,Li, Hongguang,Lang, Ming,Wang, Jian
supporting information, p. 5589 - 5593 (2020/07/08)
An unprecedented palladium(II)-catalyzed oxidative decarboxylative [2 + 2 + 1] annulation of cinnamic acids with alkynes has been developed for the synthesis of polysubstituted pentafulvenes. Ag2CO3 and DMSO are essential for the reaction. This protocol features readily available starting materials, a wide substrate scope, and moderate to excellent yields. Moreover, various significant frameworks can be easily obtained from the late-stage transformations of pentafulvenes via oxidation, reduction, and Scholl-type reaction.
Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes: Synthesis of unsymmetrical diarylethynes
Chen, Qiang,Fu, Liyan,Nishihara, Yasushi
supporting information, p. 7977 - 7980 (2020/09/09)
Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes is described. This reaction not only effectively inhibits the formation of undesired homocoupled products by avoiding the addition of a base, but also exhibits a wide substrate scope to provide a general access to diverse unsymmetrical diarylethynes.
A series of (NHC)Pd(N?O)(OAc) complexes: synthesis, characterization and catalytic activities towards desulfinative Sonogashira coupling of arylsulfonyl hydrazides with arylalkynes
Lu, Jian-Zhong,Wang, Tian,Yang, Jin,Zhao, Ya-Yu,Zhu, Guang-Hao
, (2020/02/11)
A series of well-defined N-heterocyclic carbene palladium (II) complexes with general formula (NHC)Pd(N?O)(OAc) were prepared through reaction of Pd (NHC)(OAc)2(H2O) with 1-methyl-1H-pyrazole-3-carboxylic acid or 1-methyl-1H-indazole-3-carboxylic acid in the presence of K2CO3. These complexes were then used for desulfinative Sonogashira coupling of arylsulfonyl hydrazides with terminal alkynes. With low catalyst loading, all synthesized palladium compounds exhibited moderate to high catalytic activities for the reactions.
Diorganyl tellurides as substrates in Sonogashira coupling reactions under mild conditions
Zhang, Shaozhong,Ailneni, Chandra,Al-Mohammed Baqer, Osamah,Lolla, Mahati,Mannava, Bala Bharathi,Siraswal, Parvinlal,Yen, Changchi,Jin, Jin
supporting information, p. 217 - 225 (2019/11/22)
A new method of Sonogashira coupling reactions between diorganyl tellurides and terminal alkynes is reported. The coupling reactions are performed using Pd(dppf)Cl2 as a catalyst, CuI as a co-catalyst in the presence of K2CO3 in DMSO. The reactions are carried out at room temperature and completed within 2 h when phenyl acetylene is used as a terminal alkyne. For aliphatic terminal alkynes, such as 1-hexyne and 1-octyne, an elevated temperature and longer reaction time are needed for the completion of the reactions. This process results in good yields of Sonogashira coupling products which is applicable for diaryl, divinyl and dialkynyl tellurides but not applicable for dialkyl tellurides.
Role of substituents present in bidentate ligand frame of Cu(I) catalysts on Sonogashira cross coupling reactions
Chaudhary, Virendra Kumar,Dhara, Ashish Kumar,Ghosh, Kaushik,Kumari, Sheela,Mawai, Kiran,Mohanty, Aurobinda,Ratnam, Anand
, (2020/10/20)
Cu(I) catalysts {[Cu(L1?4)Cl(PPh3)] where L1?4 = condensed product of 2-(1-phenylhydrazinyl)-pyridine with different benzaldehydes} were synthesized and characterized by 1H NMR, 31P NMR, UV–Vis and IR techniques. Complex 2 structure was authenticated by single crystal X-ray method. Different electron donating and withdrawing substituents are present in the ligand frame of Cu(I) catalysts and their role on Sonogashira reaction was investigated. The efficiency order of catalysts for the coupling reaction was found to be 2 > 1>3 > 4, clearly indicated the role of substituents present in the ligand frame was useful to effectively catalyze the Sonogashira reaction. The products were characterized using 1H NMR and 13C NMR.
