- Deoxygenation of Nitrous Oxide and Nitro Compounds Using Bis(N-Heterocyclic Silylene)Amido Iron Complexes as Catalysts
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Herein, we report the efficient degradation of N2O with a well-defined bis(silylene)amido iron complex as catalyst. The deoxygenation of N2O using the iron silanone complex 4 as a catalyst and pinacolborane (HBpin) as a sacrificial reagent proceeds smoothly at 50 °C to form N2, H2, and (pinB)2O. Mechanistic studies suggest that the iron–silicon cooperativity is the key to this catalytic transformation, which involves N2O activation, H atom transfer, H2 release and oxygenation of the boron sites. This approach has been further developed to enable catalytic reductions of nitro compounds, producing amino-boranes with good functional-group tolerance and excellent chemoselectivity.
- Chen, Xi,Driess, Matthias,Du, Shaozhi,Mo, Zhenbo,Wang, Hao
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supporting information
(2021/12/03)
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- Catalytic Staudinger Reduction at Room Temperature
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We report an efficient catalytic Staudinger reduction at room temperature that enables the preparation of a structurally diverse set of amines from azides in excellent yields. The reaction is based on the use of catalytic amounts of triphenylphosphine as a phosphine source and diphenyldisiloxane as a reducing agent. Our catalytic Staudinger reduction exhibits a high chemoselectivity, as exemplified by reduction of azides over other common functionalities, including nitriles, alkenes, alkynes, esters, and ketones.
- Lenstra, Danny C.,Wolf, Joris J.,Mecinovi?, Jasmin
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p. 6536 - 6545
(2019/05/24)
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- Mild N-deacylation of secondary amides by alkylation with organocerium reagents
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Secondary amides are a class of highly stable compounds serving as versatile starting materials, intermediates and directing groups (amido groups) in organic synthesis. The direct deacylation of secondary amides to release amines is an important transformation in organic synthesis. Here, we report a protocol for the deacylation of secondary amides and isolation of amines. The method is based on the activation of amides with Tf2O, followed by addition of organocerium reagents, and acidic work-up. The reaction proceeded under mild conditions and afforded the corresponding amines, isolated as their hydrochloride salts, in good yields. In combination with the C-H activation functionalization methodology, the method is applicable to the functionalization of aniline as well as conversion of carboxylic derivatives to functionalized ketones.
- Wang, Ai-E.,Chang, Zong,Liu, Yong-Peng,Huang, Pei-Qiang
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supporting information
p. 1055 - 1058
(2015/09/01)
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- Synthesis, cytotoxic evaluation, and in silico studies of substituted N-alkylbromo-benzothiazoles
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In efforts to develop a new class of anticancer agents with improved efficacy and selective action, a series of N-alkylbromo-benzothiazoles were synthesized and evaluated for in vitro cytotoxic activity against various human cancer cell lines such as lung (A-549), prostate (PC-3), leukemia (THP-1), and colon (Caco-2). They were found to be highly active against prostate (PC-3) and leukemia (THP-1) cancer cells, moderately active against colon (Caco-2) cancer cells and less active against lung (A-549) cancer cells. Of the 12 compounds, two (11d, 11j) exhibit IC50 values of ≤ 1 μM against leukemia (THP-1) cancer cell lines. Compound 11l showed significant cytotoxic activity against the PC-3 (IC50 = 0.6 μM), THP-1 (IC50 = 3 μM) and Caco-2 cell lines (IC50 = 9.9 μM), respectively. Docking study of the synthesized ligand was done on epidermal growth factor receptor using ArgusLab flexible docking, to determine their observed activity. Further QSAR investigations with stepwise multiple linear regression analysis were applied to find correlation between various physicochemical parameters and anticancer activity. The QSAR results showed that anticancer activity could be modeled with descriptors. The predictive ability of models was cross-validated by observation of the low residual activity values and adjusted coefficient of variation (radj2) obtained by leave-one-out technique.
- Gill, Rupinder Kaur,Singh, Gagandeep,Sharma, Anuradha,Bedi,Saxena
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p. 4211 - 4222
(2013/09/02)
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- Reduction of aromatic and aliphatic nitro groups to anilines and amines with hypophosphites associated with Pd/C
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The reduction of aromatic and aliphatic nitro groups to anilines and amines is performed with good yield and selectivity in short reaction times. A mixture of sodium hypophosphite and phosphinic acid is used in the presence of a heterogeneous catalyst 2.5 mol% of Pd/C (5%) in a biphasic water/2-MeTHF system.
- Baron, Marc,Metay, Estelle,Lemaire, Marc,Popowycz, Florence
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p. 1006 - 1015
(2013/07/26)
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- Kinetics and mechanism of the anilinolysis of dicyclohexyl phosphinic chloride in acetonitrile
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The nucleophilic substitution reactions of dicyclohexyl phosphinic chloride [3; cHex2P(=O)Cl] with substituted anilines (XC6H 4NH2) and deuterated anilines (XC6H 4ND2) are investigated kinetically in acetonitrile at 60.0 °C. The anilinolysis rate is too slow to be rationalized by the stereoelectronic effects. The rate is contrary to expectations for the electronic influence of the two ligands and exhibits exceptionally great negative deviation from the Taft's eq. The deuterium kinetic isotope effects (DKIEs) involving deuterated anilines invariably change from primary normal (kH/kD > 1; max kH/kDt = 1.10 with X = 4-MeO) with the strongly basic anilines (X = 4-MeO, 4-Me, 3-Me) to secondary inverse (kH/kDt H/k Dt = 0.673 with X = 3-Cl) with the weakly basic anilines (X = H, 4-F, 4-Cl, 3-Cl). A concerted SN2 mechanism is proposed on the basis of both secondary inverse and primary normal DKIEs. The obtained DKIEs imply that the fraction of a frontside attack increases as the aniline becomes more basic. A hydrogen-bonded, four-center-type transition state is suggested for a frontside attack, while the trigonal bipyramidal pentacoordinate transition state is suggested for a backside attack.
- Ul Hoque, Md. Ehtesham,Lee, Hai Whang
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experimental part
p. 1997 - 2002
(2012/02/01)
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- Synthesis, insecticidal activities, and molecular docking studies of 1,5-disubstituted-1,3,5-hexahydrotriazine-2-(N-nitro)imines
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Figure represented. A series of novel neonicotinoids analogs were designed by modifying the pharmacophore of imidacloprid to 1,3,5-hexahydrotriazine conjugated to nitroimine (iNNO2) and introducing the phenyl or arylmethyl at the 5-position, and their insecticidal activities were evaluated. Introducing a heterocyclic methyl at 5-position increased the insecticidal activities, whereas other phenyl, phenylmethyl or phenylethyl substituents were unfavorable to activities. Molecular docking study was also performed to clarify the interactions of the most potent analog 1-((6-chloropyridin-3-yl)methyl)-5- (3-pyridylmethyl)-1,3,5-hexahydrotriazine-2-(N-nitro) imine (7s) with the target nicotinic acetylcholine receptor, which explained the structure-activity relationships observed in vitro, and revealed further possibilities for insecticide development.
- Sun, Chuan-Wen,Wang, Hai-Feng,Zhu, Jun,Yang, Ding-Rong,Jin, Jia,Xing, Jia-Hua
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experimental part
p. 829 - 835
(2011/09/16)
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- Highly chemo- and regioselective reduction of aromatic nitro compounds using the system silane/oxo-rhenium complexes
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(Chemical Equation Presented) The reduction of aromatic nitro compounds to the corresponding amines with silanes catalyzed by high valent oxo-rhenium complexes is reported. The catalytic systems PhMe2SiH/ReIO 2(PPh3)2 (5 mol %) and PhMe2SiH/ ReOCl3(PPh3)2 (5 mol %) reduced efficiently a series of aromatic nitro compounds in the presence of a wide range of functional groups such as ester, halo, amide, sulfone, lactone, and benzyl. This methodology also allowed the regioselective reduction of dinitrobenzenes to the corresponding nitroanilines and the reduction of an aromatic nitro group in presence of an aliphatic nitro group. 2009 American Chemical Society.
- De Noronha, Rita G.,Romao, Carlos C.,Fernandes, Ana C.
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supporting information; experimental part
p. 6960 - 6964
(2010/03/03)
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- Synthesis of primary amines by the electrophilic amination of Grignard reagents with 1,3-dioxolan-2-one O-sulfonyloxime
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(Chemical equation presented) Primary amines are prepared by the electrophilic amination of Grignard reagents with 4,4,5,5-tetramethyl-1,3- dioxolan-2-one O-phenylsulfonyloxime and the acidic hydrolysis of the resulting imines.
- Kitamura, Mitsuru,Suga, Takahiro,Chiba, Shunsuke,Narasaka, Koichi
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p. 4619 - 4621
(2007/10/03)
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