- Cobalt-Catalyzed Deoxygenative Hydroboration of Nitro Compounds and Applications to One-Pot Synthesis of Aldimines and Amides
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The commercially available and bench-stable Co(acac)2 ligated with bis[(2-diphenylphosphino)phenyl] ether (dpephos) was employed for selective room temperature hydroboration of nitro compounds with HBPin (TOF up to 4615 h?1), tolerating halide, hydroxy, amino, ether, ester, lactone, amide and heteroaromatic functionalities. These reactions offered a direct access to a variety of N-borylamines RN(H)BPin, which were in situ treated with aldehydes and carboxylic acids to produce a series of aldimines and secondary carboxamides without the need for dehydrating and/or coupling reagents. Combination of these transformations in a sequential one-pot manner allowed for direct and selective synthesis of aldimines and secondary carboxamides from readily available and inexpensive nitro compounds.
- Gudun, Kristina A.,Hayrapetyan, Davit,Khalimon, Andrey Y.,Segizbayev, Medet,Slamova, Ainur,Zakarina, Raikhan
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- Reversible capture and release of aromatic amines by vicinal tricarbonyl compound
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In this paper, we report reversible capture and release of aromatic amines by diphenylpropanetrione (DPPT). Addition of aromatic amines to the central carbonyl group occurred readily at ambient temperature to provide the aromatic amine adducts of DPPT (DPPT-aromatic amines), which has a hemiaminal structure. On the other hand, washing a solution of DPPT-aromatic amine with diluted hydrochloric acid (HCl) enabled successful recovery of DPPT to demonstrate the reversible nature of this system.
- Yuki, Tatsuya,Yonekawa, Morio,Furusho, Yoshio,Sei, Yoshihisa,Tomita, Ikuyoshi,Endo, Takeshi
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p. 2868 - 2873
(2016/05/19)
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- The ortho effect on the acidic and alkaline hydrolysis of substituted formanilides
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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.
- Desai, Salil Dileep,Kirsch, Lee E.
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p. 471 - 488
(2015/06/30)
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- Continuous-flow hydrogenation of olefins and nitrobenzenes catalyzed by platinum nanoparticles dispersed in an amphiphilic polymer
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A method for the flow hydrogenation of olefins and nitrobenzenes in a continuous-flow reactor containing platinum nanoparticles dispersed on an amphiphilic polystyrene-poly(ethylene glycol) resin (ARP-Pt) was developed. The hydrogenation of olefins and nitrobenzenes was completed within 31 seconds in the continuous-flow system containing ARP-Pt, giving the corresponding hydrogenated products in up to 99% yield with good chemoselectivity. Moreover, long-term (63-70 h) continuous-flow hydrogenation of styrene and nitrobenzene produced more than ten grams of ethylbenzene and aniline, respectively, without significant loss of catalytic activity. The flow hydrogenation system provides an efficient and practical method for the chemoselective reduction of olefins and nitrobenzenes. This journal is
- Osako, Takao,Torii, Kaoru,Tazawa, Aya,Uozumi, Yasuhiro
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p. 45760 - 45766
(2015/06/08)
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- HEXAHYDROBENZO(A)PHENANTHRIDINE COMPOUNDS
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Trans-hexahydrobenzophenanthridines of the formula STR1 wherein R is hydrogen or C 1-C 4 alkyl; R 1 is hydrogen, benzoyl or pivaloyl; and x is hydrogen, chloro, bromo, iodo or a group of the formula OR 2, are novel ligands for dopamine receptors.
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