- Enzymatic Primary Amination of Benzylic and Allylic C(sp3)-H Bonds
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Aliphatic primary amines are prevalent in natural products, pharmaceuticals, and functional materials. While a plethora of processes are reported for their synthesis, methods that directly install a free amine group into C(sp3)-H bonds remain unprecedented. Here, we report a set of new-to-nature enzymes that catalyze the direct primary amination of C(sp3)-H bonds with excellent chemo-, regio-, and enantioselectivity, using a readily available hydroxylamine derivative as the nitrogen source. Directed evolution of genetically encoded cytochrome P411 enzymes (P450s whose Cys axial ligand to the heme iron has been replaced with Ser) generated variants that selectively functionalize benzylic and allylic C-H bonds, affording a broad scope of enantioenriched primary amines. This biocatalytic process is efficient and selective (up to 3930 TTN and 96percent ee), and can be performed on preparative scale.
- Jia, Zhi-Jun,Gao, Shilong,Arnold, Frances H.
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supporting information
p. 10279 - 10283
(2020/07/27)
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- NITROGEN-CONTAINING SATURATED HETEROCYCLIC COMPOUND
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The present invention provides a compound represented by the following formula (I) or its pharmaceutically acceptable salt: [wherein, R1 represents optionally substituted C1-4 alkyl, n shows integer of 1 to 4, R2 represents optionally substituted C1-4 alkyl or hydrogen atom, R3 represents optionally substituted C1-4 alkyl, R4a, R4b, R4c, and R4d, similarly or differently, represent optionally substituted C6-14 aryl, optionally substituted C1-4 alkyl, or hydrogen atom and the like, A represents optionally substituted C6-14 aryl or optionally substituted 5 to 11 membered heteroaryl].
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Paragraph 0344
(2016/08/29)
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- Evidence for significant through-space and through-bond electronic coupling in the 1,4-diphenylcyclohexane-1,4-diyl radical cation gained by absorption spectroscopy and DFT calculations
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Photoinduced single-electron-transfer promoted oxidation of 2,5-diphenyl-l,5-hexadiene by using N-methylquinolinium tetrafluoroborate/ biphenyl co-sensitization takes place with the formation of an intense electronic absorption band at 476 nm, which is attributed to the 1,4-diphenylcyclohexane-1,4-diyl radical cation. The absorption maximum (λob) of this transient occurs at a longer wavelength than is expected for either the cumyl radical or the cumyl cation components. Substitution at the para positions of the phenyl groups in this radical cation by CH3O, CH3, F, Cl, and Br leads to an increasingly larger redshift of λob. A comparison of the ρ value, which was obtained from a Hammett plot of the electronic transition energies of the radical cations versus σ+, with that for the cumyl cation shows that the substituent effects on the transition energies for the 1,4-diarylcyclohexane-1,4-diyl radical cations are approximately one half of the substituent effects on the transition energies of the cumyl cation. The observed substitu_ent-induced redshifts of λob and the reduced sensitivity of λob to substituent changes are in accordance with the proposal that significant through-space and -bond electronic interactions exist between the cumyl radical and the cumyl cation moieties of the 1,4-diphenylcyclohexane-1,4-diyl radical cation. This proposal gains strong support from the results of density functional theory (DFT) calculations. Moreover, the results of time-dependent DFT calculations indicate that the absorption band at 476 nm for the 1,4-diphenylcyclohexane-1,4-diyl radical cation corresponds to a SOMO-3-SOMO transition.
- Ikeda, Hiroshi,Hoshi, Yosuke,Namai, Hayato,Tanaka, Futoshi,Goodman, Joshua L.,Mizuno, Kazuhiko
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p. 9207 - 9215
(2008/12/21)
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- Organocerium reactions of benzamides and thiobenzamides: A direct synthesis of tertiary carbinamines
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A simple and efficient process has been developed for the direct conversion of benzamides and thiobenzamides into tertiary carbinamines. A synthesis of benzonitriles from simple benzamides and a thiobenzamide is also described.
- Calderwood, David J.,Davies, Roy V.,Rafferty, Paul,Twigger, Helen L.,Whelan, Helen M.
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p. 1241 - 1244
(2007/10/03)
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- Steroid derivatives for the treatment of prostatic hypertrophy their preparation and uses
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The invention includes compounds of formula (I): STR1 in which R1 is hydrogen, alkyl, aryl-substituted alkyl or aromatic heterocyclic-substituted alkyl; R2 is aryl-substituted alkyl, aromatic heterocyclic-substituted alkyl or diarylamino; and R3 is carboxy or a group of formula --CONHSO2 R4 wherein R4 is alkyl; and pharmaceutically acceptable salts and esters of the compounds. The compounds have valuable 5α-reductase inhibitory activity and can thus be used for the treatment and prophylaxis of, inter alia, prostatic hypertrophy as well as other disorders arising from excess levels of 5α-dihydro-testosterone.
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- Synthesis and Herbicidal Activities of 1,2-Benzisoxazole-3-acetamide Derivatives
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Many 1,2-benzisoxazole-3-acetamides were synthesized and their herbicidal activities in the paddy field were studied.Of the compounds tested, N-α,α-dimethylbenzyl-2-bromo-(1,2-benzisoxazol-3-yl)acetamide 10a was the most effective.Details of the synthesis and the results of herbicidal evaluations are given.
- Sato, Kazuo,Honma, Toyokuni,Sugai, Soji
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p. 3563 - 3568
(2007/10/02)
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