2860-30-2Relevant academic research and scientific papers
Tetracoordinate borates as catalysts for reductive formylation of amines with carbon dioxide
Du, Chen-Xia,Huang, Zijun,Jiang, Xiaolin,Li, Yuehui,Makha, Mohamed,Wang, Fang,Zhao, Dongmei
supporting information, p. 5317 - 5324 (2020/09/17)
We report sodium trihydroxyaryl borates as the first robust tetracoordinate organoboron catalysts for reductive functionalization of CO2. These catalysts, easily synthesized from condensing boronic acids with metal hydroxides, activate main group element-hydrogen (E-H) bonds efficiently. In contrast to BX3 type boranes, boronic acids and metal-BAr4 salts, under transition metal-free conditions, sodium trihydroxyaryl borates exhibit high reactivity of reductive N-formylation toward a variety of amines (106 examples), including those with functional groups such as ester, olefin, hydroxyl, cyano, nitro, halogen, MeS-, ether groups, etc. The over-performance to catalyze formylation of challenging pyridyl amines affords a promising alternative method to the use of traditional formylation reagents. Mechanistic investigation supports electrostatic interactions as the key for Si/B-H activation, enabling alkali metal borates as versatile catalysts for hydroborylation, hydrosilylation, and reductive formylation/methylation of CO2.
Mesostructure organic-inorganic hybrid ionic liquids based on heteropoly acids: Effect of linkage on the molecular structure and catalytic activity
Shahebrahimi, Shabnam,Rafiee, Ezzat,Sadrjavadi, Komail
, (2019/08/30)
The new inorganic–organic hybrids based on SO3H-functionalized ionic liquids (ILs) and Keggin-type heteropoly acids (H3PW12O40, H3PMo12O40, and H4SiW12O40; HPAs) are prepared and characterized by FT-IR, NMR, XRD, CV, SEM/EDX, ICP-OES, BJH and UV. Different molecular structures according to the different inorganic part were also proved. Potentiometric titration showed a good relationship between catalytic activity and acidity of the catalysts. Electrochemical aspects showed electron transfer ability of the compounds. For understanding catalytic activities of the HPA-IL hybrids in N-formylation reaction, effect of catalyst composition, substrate, and reaction conditions were studied. The best SO3H-functionalized ionic liquid catalyst was readily recovered and reused for four runs. Easy preparation of the catalyst, simple and easy work-up, mild reaction conditions, low cost, excellent yields and short reaction times are the key features of this work.
Potassium tert-Butoxide Prompted Highly Efficient Transamidation and Its Coordination Radical Mechanism
Tan, Zhiyong,Li, Zhenhua,Ma, Yao,Qin, Jinjing,Yu, Chuanming
, p. 4538 - 4545 (2019/07/18)
A simple and highly efficient protocol was developed for the transamidation of N,N-disubstituted amides with primary amines in the presence of tBuOK, affording desired products in good to excellent yields. This reaction proceeded under nitrogen atmosphere and featured extensive substrate tolerance. Experimental investigation suggested that a coordination radical process enhanced this transformation.
KOtBu-Promoted Transition-Metal-Free Transamidation of Primary and Tertiary Amides with Amines
Ghosh, Tridev,Jana, Snehasish,Dash, Jyotirmayee
supporting information, p. 6690 - 6694 (2019/09/12)
This work discloses transamidation of primary and tertiary amides with a range of aryl, heteroaryl, and aliphatic amines using potassium tert-butoxide. The reaction proceeds at room temperature under transition-metal-free conditions providing secondary amides in high yields. Moreover, reaction of cyclopropyl amine with tertiary amides proceeds with ring-opening to provide a rapid access to enamides.
The ortho effect on the acidic and alkaline hydrolysis of substituted formanilides
Desai, Salil Dileep,Kirsch, Lee E.
, p. 471 - 488 (2015/06/30)
The kinetics of formanilides hydrolysis were determined under first-order conditions in hydrochloric acid (0.01-8 M, 20-60°C) and in hydroxide solutions (0.01-3 M, 25 and 40°C). Under acidic conditions, second-order specific acid catalytic constants were used to construct Hammett plots. The ortho effect was analyzed using the Fujita-Nishioka method. In alkaline solutions, hydrolysis displayed both first- and second-order dependence in the hydroxide concentration. The specific base catalytic constants were used to construct Hammett plots. Ortho effects were evaluated for the first-order dependence on the hydroxide concentration. Formanilide hydrolyzes in acidic solutions by specific acid catalysis, and the kinetic study results were consistent with the AAC2 mechanism. Ortho substitution led to a decrease in the rates of reaction due to steric inhibition of resonance, retardation due to steric bulk, and through space interactions. The primary hydrolytic pathway in alkaline solutions was consistent with a modified BAC2 mechanism. The Hammett plots for hydrolysis of meta- and para-substituted formanilides in 0.10 M sodium hydroxide solutions did not show substituent effects; however, ortho substitution led to a decrease in rate constants proportional to the steric bulk of the substituent.
Palladium-catalyzed C(sp2)-H arylation using formamide as a transformable directing group
Wan, Congqing,Zhao, Jiaji,Xu, Mingfang,Huang, Jinbo
, p. 4751 - 4756 (2014/06/09)
A new process for the ortho arylation of formanilides through palladium-catalyzed C-H activation is described. Formamide is reported as a transformable directing group in the transition-metal-catalyzed C-H functionalization reaction. The resulting biarylformanilide products can be readily transformed to the corresponding biarylisocyanides or N-heterocycles.
Deep eutectic solvent promoted highly efficient synthesis of N, N'-diarylamidines and formamides
Azizi, Najmadin,Gholibeglo, Elham,Babapour, Mahbobe,Ghafuri, Hossein,Bolourtchian, Seyed Mohammad
, p. 768 - 773 (2012/10/30)
A deep eutectic solvent was used as a dual catalyst and reaction medium for the efficient N-formylation of aromatic amines without hazardous organic solvent and catalyst. Treatment of aromatic amines with trimethyl orthoformate and formic acid in deep eutectic solvent at 70 °C gives the corresponding N-formyl derivatives in good to excellent yields. This simple ammonium deep eutectic solvent, easily synthesized from choline chloride and SnCl2, with 100% atom economy and making it applicable to industry and laboratory. Furthermore, heating the trimethyl orthoformate and aromatic primary amines in the deep eutectic solvent results in formation of the corresponding N,N'-diarylamidines in high yields.
Organic reactions in water: A practical and convenient method for the N-formylation of amines in water
Kaboudin, Babak,Khodamorady, Minoo
experimental part, p. 2905 - 2907 (2011/02/26)
A simple, efficient, scaleable process has been developed for the N-formylation amines in water. Treatment of amines with triethyl orthoformate in water at reflux under neutral conditions without any additives gives the corresponding N-formyl derivatives in good yields. Georg Thieme Verlag Stuttgart - New York.
