18277-20-8Relevant academic research and scientific papers
C?C Bond Formation of Benzyl Alcohols and Alkynes Using a Catalytic Amount of KOtBu: Unusual Regioselectivity through a Radical Mechanism
Kumar, Amit,Janes, Trevor,Chakraborty, Subrata,Daw, Prosenjit,von Wolff, Niklas,Carmieli, Raanan,Diskin-Posner, Yael,Milstein, David
supporting information, p. 3373 - 3377 (2019/02/14)
We report a C?C bond-forming reaction between benzyl alcohols and alkynes in the presence of a catalytic amount of KOtBu to form α-alkylated ketones in which the C=O group is located on the side derived from the alcohol. The reaction proceeds under thermal conditions (125 °C) and produces no waste, making the reaction highly atom efficient, environmentally benign, and sustainable. Based on our mechanistic investigations, we propose that the reaction proceeds through radical pathways.
Synthesis of Aryl Alkynes via Copper Catalyzed Decarboxylative Alkynylation of 2-Nitrobenzoic Acids
Yu, Yongqi,Chen, Xiang,Wu, Qianlong,Liu, Da,Hu, Liang,Yu, Lin,Tan, Ze,Gui, Qingwen,Zhu, Gangguo
supporting information, p. 8556 - 8566 (2018/06/29)
An efficient protocol for the synthesis of internal aryl alkynes was achieved via Cu-catalyzed decarboxylative cross-coupling reactions, and to the best of our knowledge, this is the first example of a Cu-catalyzed decarboxylative alkynylation of benzoic acids with terminal alkynes. This approach utilizes simple Cu salt as catalyst and O2, an abundant, clean, and green material, as the oxidant. The reaction tolerates various functional groups, and a variety of internal aryl alkynes were synthesized in 46-83% yields.
Room-Temperature Alkynylation of Phosphine Oxides with Copper Acetylides: Practical Synthesis of Alkynylphosphine Oxides
Gérard, Phidéline,Veillard, Romain,Alayrac, Carole,Gaumont, Annie-Claude,Evano, Gwilherm
supporting information, p. 633 - 638 (2017/01/18)
An efficient procedure for the synthesis of alkynylphosphine oxides based on the oxidative alkynylation of secondary phosphine oxides with copper acetylides was developed. Activation with molecular oxygen in the presence of either a mixture of 1,2-dimethylimidazole and triethylamine or N-methylimidazole alone enabled the formal umpolung of the poorly nucleophilic copper acetylides, which were coupled with phosphine oxides under remarkably mild conditions. Notable features of this procedure are the availability of the starting materials, its user-friendliness, and its mild conditions, which allow the synthesis of complex alkynylphosphine oxides.
Mesoporous Copper/Manganese Oxide Catalyzed Coupling of Alkynes: Evidence for Synergistic Cooperative Catalysis
Biswas, Sourav,Mullick, Kankana,Chen, Sheng-Yu,Kriz, David A.,Shakil, Md,Kuo, Chung-Hao,Angeles-Boza, Alfredo M.,Rossi, Angelo R.,Suib, Steven L.
, p. 5069 - 5080 (2016/08/18)
Copper oxide supported on mesoporous manganese oxide (meso Cu/MnOx) was synthesized by an inverse micelle templated evaporation induced self-assembly procedure. Controlled aggregation of nanoparticles and a monomodal size distribution of mesopores with tunable structural properties were observed. The material possessed superior catalytic activity in the aerobic oxidative coupling of terminal alkynes. Excellent conversion (>99% in most cases) and selectivity were observed in both homocoupling and cross-coupling of alkynes using the optimized reaction conditions. Use of air as the sole oxidant, avoidance of any kind of additives, ease of product separation, great functional group tolerability, wide synthetic scope, and superior reusability (up to eighth cycle) are the notable features of our catalytic protocol. While the reaction mechanism was elucidated, a synergistic cooperative effect between the copper and manganese has been established, which is responsible for the superior catalytic activity. The labile lattice oxygen of the meso Cu/MnOx played a vital role in deprotonation of the alkyne proton, as supported by TPD and TGA studies. Moreover, for the first time, we designed model complexes for the active sites of the catalyst by DFT calculations and provided a qualitative description of the coupling mechanism, which supports the experimental findings.
Copper(II)-Promoted, One-Pot Conversion of 1-Alkynes with Anhydrides or Primary Amines to the Respective 2,5-Disubstituted Furans or Pyrroles under Microwave Irradiation Conditions
Lee, Hyejeong,Yi, Yeonhui,Jun, Chul-Ho
, p. 3485 - 3490 (2016/01/25)
Furans and pyrroles are prepared from 1-alkynes by using a Cu(II)-promoted, one-pot, microwave irradiation method. Glaser coupling of 1-alkynes and cyclization of the resulting 1,3-diyne in the presence of an anhydride or a primary amine results in the formation of the respective 2,5-diaryl- or 2,5-dialkyl-substituted furans and pyrroles.
Aqueous Sonogashira coupling of aryl halides with 1-alkynes under mild conditions: Use of surfactants in cross-coupling reactions
Roberts, Gina M.,Lu, Wenya,Woo, L. Keith
, p. 18960 - 18971 (2015/06/01)
Aqueous Sonogashira coupling between lipophilic terminal alkynes and aryl bromides or iodides gave moderate to high yields at 40°C using readily available and inexpensive surfactants (2.0 w/v% in water) such as SDS and CTAB. The catalyst precursor was 2 m
A mild CuI-catalyzed Glaser-type homo-coupling reaction using α,α-dibromo-β-dicarbonyl compounds as oxidants
Fan, Xiaohui,Li, Na,Shen, Tong,Cui, Xiao-Meng,Lv, Hao,Zhu, Hong-Bo,Guan, Yong-Hong
supporting information, p. 256 - 261 (2014/01/06)
Exploration of α,α-dibromo-β-dicarbonyl compounds as novel organic oxidants for the mild Cu(I)-catalyzed Glaser-type homo-coupling reaction has been achieved, which provides an alternatively efficient pathway for the construction of 1,3-conjugated structures. In addition, the mechanism of this reaction was investigated.
Unsymmetrical coupling of 1-chloroalkynes and terminal alkynes under experimental Sonogashira conditions
Christensen, Mikkel Andreas,Rimmen, Morten,Nielsen, Mogens Brondsted
supporting information, p. 2715 - 2719 (2014/01/06)
The coupling of a 1-chloroalkyne and a terminal alkyne to furnish a 1,3-butadiyne under experimental Sonogashira conditions is investigated. Through competition experiments, it is found that 1-chloroalkynes provide cross-coupling products as efficiently (or slightly better) in comparison with iodobenzenes, and almost as effectively as vinyl bromides. Yet, in regard to the degree of conversion into various products, chloroalkynes are the most reactive of all the substrates examined under the explored conditions. Optimized conditions for this cross-coupling reaction are presented. Georg Thieme Verlag Stuttgart New York.
Unprecedented synthesis of alkynylphosphine-boranes through room-temperature oxidative alkynylation
Jouvin, Kevin,Veillard, Romain,Theunissen, Cedric,Alayrac, Carole,Gaumont, Annie-Claude,Evano, Gwilherm
, p. 4592 - 4595 (2013/09/24)
An original and user-friendly synthesis of alkynylphosphine-boranes, useful building blocks in organic synthesis, based on an oxidative P-alkynylation reaction with readily available copper acetylides is reported. The ability of a secondary phosphine protected with a borane to undergo oxidative coupling without oxidation of the P-moiety is demonstrated for the first time. The reaction, which proceeds at room temperature, is applicable to the preparation of enantioenriched and structurally complex alkynylphosphine-boranes.
Copper-catalyzed synthesis of 2,4-disubstituted allenoates from α-diazoesters
Hassink, Matthew,Liu, Xiaozhong,Fox, Joseph M.
scheme or table, p. 2388 - 2391 (2011/06/25)
Chemical equations presented. A Cu-catalyzed method for coupling α-substituted-α-diazoesters with terminal alkynes to give substituted allenoates is described. Key to the development of a selective method was the recognition that an adventitous base catalyzes the isomerization to form the allenoate product. A plausible mechanism is proposed, based in part on evidence against a mechanism that involves a Cu(I)-acetylide as a low-valent intermediate.
