- (Diacetoxyiodo)benzene-Mediated Transition-Metal-Free Amination of C(sp3)-H Bonds Adjacent to Heteroatoms with Azoles: Synthesis of N-Alkylated Azoles
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A novel PhI(OAc) 2 -mediated cross-dehydrogenative coupling reaction of α-C(sp 3)-H bonds adjacent to a hetero atom with various azoles has been developed, which provides an alternative method for constructing C-N bonds with high atom efficiency. This new protocol requires no metal catalyst and it provides ready access to a wide range of N-alkylated azole derivatives in moderate to excellent yields by using commercially available PhI(OAc) 2 as the sole oxidant. Furthermore, the method is effective on a gram scale, which highlights the practicality of this transformation. The result of radical-captured experiments indicated that the transformation might involve a free-radical pathway.
- Sun, Bin,Yan, Zhiyang,Jin, Can,Su, Weike
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supporting information
p. 2432 - 2436
(2018/11/23)
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- Cross-dehydrogenative coupling of azoles with α-c(sp3)-h of ethers and thioethers under metal-free conditions: Functionalization of h-n azoles via c-h activation
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A metal-free cross-dehydrogenative coupling method for the synthesis of N-substituted azoles has been developed. The TBAI/TBHP system catalyzed the coupling of azoles with ethers and thioethers via α-C(sp3)-H activation. Under the optimized conditions, a diverse range of un/substituted azoles such as 1H-benzimidazole, 9H-purine, 1H-benzotriazole, 1H-1,2,3-triazole, 1H-1,2,4-triazole, and 1H-pyrazole were successfully employed for coupling with various ethers and thioethers such as tetrahydrofuran, tetrahydropyran, 1,4-dioxane, diethyl ether, tetrahydrothiophene, and 1,3-dithiolane.
- Aruri, Hariprasad,Singh, Umed,Sharma, Sumit,Gudup, Satish,Bhogal, Mukesh,Kumar, Sanjay,Singh, Deepika,Gupta, Vivek K.,Kant, Rajni,Vishwakarma, Ram A.,Singh, Parvinder Pal
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p. 1929 - 1936
(2015/02/19)
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- Iron-catalyzed N -alkylation of azoles via oxidation of C-H bond adjacent to an oxygen atom
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Figure presented Azole derivatives were synthesized by iron-catalyzed oxidative reactions of azoles and ethers in good to excellent yields. A wide variety of azoles and ethers were selectively transformed into the corresponding oxidative coupling products under neutral reaction conditions.
- Pan, Shiguang,Liu, Jinhua,Li, Huanrong,Wang, Zhenyu,Guo, Xingwei,Li, Zhiping
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supporting information; experimental part
p. 1932 - 1935
(2010/07/04)
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- REACTION OF 1-(1-ALKOXYALKYL)-1-H-1,2,4-TRIAZOLE WITH AMIDES
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1-(1-Alkoxyalkyl)-1H-1,2,4-triazoles (4) were prepared by treating acetals (1) with 1H-1,2,4-triazole (2) in the presence of pyridinium p-toluenesulfonate (3).The alkoxy group of 4-was substituted with -NR4COR3 group by treating with carboxamides to give various 1-(1-acylaminoalkyl)-1H-1,2,4-triazole (6) in variable yields.
- Ohta, Shunsaku,Maruyama, Akihiko,Kawasaki, Ikuo,Hatakeyama, Shoko,Ichikawa, Michiyo,Guro, Tomoko
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p. 2029 - 2036
(2007/10/02)
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- MECHANISMS FOR THE SOLVOLYTIC DECOMPOSITIONS OF NUCLEOSIDE ANALOGUES-I. ACIDIC HYDROLYSIS OF 2-SUBSTITUTED 1-(1-ETHOXYETHYL)BENZIMIDAZOLES
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A few 2-substituted 1-(1-ethoxyethyl)benzimidazoles have been prepared and the rate constants for their hydrolysis measured at various temperatures and oxonium ion concentrations.The formal kinetics followed and the effect of varying the 2-substitution on the hydrolysis rate suggest that the acid-catalyzed cleavage of these compounds involves a rapid initial protonation of the benzimidazole ring and a subsequent rate-limiting heterolysis of the protonated substrate to form a free nitrogen base and an oxocarbenium ion derived from the ethoxyethyl group.The values obtained for the entropy of activation are consistent with the assumed u nimolecular nature of the rate-limiting step.The effects of 2-substituents on the acidities of the protonated substrates and their heterolysis rates have been compared.The latter partial reaction has been suggested to be the subject of steric acceleration.
- Loennberg, Harri,Kaeppi, Rainer
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p. 913 - 918
(2007/10/02)
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