- Ir-Catalyzed Ligand-Free Directed C-H Borylation of Arenes and Pharmaceuticals: Detailed Mechanistic Understanding
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An efficient method for Ir-catalyzed ligand free ortho borylation of arenes (such as, 2-phenoxypyridines, 2-anilinopyridines, benzylamines, benzylpiperazines, benzylmorpholines, benzylpyrrolidine, benzylpiperidines, benzylazepanes, α-amino acid derivatives, aminophenylethane derivatives, and other important scaffolds) and pharmaceuticals has been developed. The reaction underwent via an interesting mechanistic pathway, as revealed by the detailed mechanistic investigations by using kinetic isotope studies and DFT calculations. The catalytic cycle is found to involve the intermediacy of an Ir-boryl complex where the substrate C-H activation is the turnover determining step, intriguingly without any appreciable primary KIE. The method displays a broad range of substrate scope and functional group tolerance. Numerous late-stage borylation of various important molecules and drugs were achieved using this developed strategy. The borylated compounds were further converted into more valuable functionalities. Moreover, utilizing the benefit of the B-N intramolecular interaction of the mono borylated compounds, an operationally simple method has been developed for the selective diborylation of 2-phenoxypyridines and numerous functionalized arenes. Furthermore, the synthetic utility has been showcased with the removal of the pyridyl directing group from the borylated product to achieve ortho borylated phenol along with the ipso-borylation for the preparation of 1,2-diborylated benzene.
- Mahamudul Hassan, Mirja Md,Mondal, Biplab,Singh, Sukriti,Haldar, Chabush,Chaturvedi, Jagriti,Bisht, Ranjana,Sunoj, Raghavan B.,Chattopadhyay, Buddhadeb
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supporting information
p. 4360 - 4375
(2022/03/16)
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- Electrolysis promoted reductive amination of electron-deficient aldehydes/ketones: a green route to the racemic clopidogrel
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An electrocatalytic reductive amination of electron-deficient aldehydes/ketones was developed, which could be used in the synthesis of functionalized tertiary amines and large scale preparation of racemic clopidogrel. A plausible mechanism involving an iminium cation intermediate was proposed.
- Zhang, Qianyun,Zhu, Wen,Yao, Jinzhong,Zhou, Hongwei,Li, Xiaofang
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supporting information
p. 8462 - 8466
(2018/12/13)
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- A formal method for the de-N,N-dialkylation of Sommelet-Hauser rearrangement products
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Selective amine de-alkylation enables the conversion of Sommelet-Hauser rearrangement products into 2-aryl-2-bromoacetic acid derivatives. These compounds are valuable synthetic intermediates in the synthesis of α-aryl-α-amino or α-aryl-β-amino acid deriv
- Tayama, Eiji,Sato, Ryota,Takedachi, Keisuke,Iwamoto, Hajime,Hasegawa, Eietsu
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p. 4710 - 4718
(2012/07/28)
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- Sigmatropic rearrangement of ammonium ylideskey step in the synthesis of methyl 2-formylphenyl acetate
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N-Cyanomethyl-N,N-dimethyl-N-(-methoxycarbonyl)benzylammonium salts 5 were synthesized and treated with different base/solvent systems, giving the products of sigmatropic rearrangements [2,3] 7 and [1,2] 8. In reactions carried out in liquid ammonia, [2,3] rearrangement definitively prevailed. Pure 7(or mixture of 7 and 8) were deprotected to afford methyl 2-formylphenyl acetate (9) in good yield.
- Kowalkowska, Anna,Jonczyk, Andrzej
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experimental part
p. 3308 - 3317
(2011/09/21)
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- Discovery of triarylethanolamine inhibitors of the Kv1.5 potassium channel
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A series of triarylethanolamine inhibitors of the Kv1.5 potassium channel have been prepared and evaluated for their effects in vitro and in vivo. The structure-activity relationship (SAR) studies described herein led to the development of potent, selecti
- Beshore, Douglas C.,Liverton, Nigel J.,McIntyre, Charles J.,Claiborne, Christopher F.,Libby, Brian,Culberson, J. Christopher,Salata, Joseph J.,Regan, Christopher P.,Lynch, Joseph J.,Kiss, Laszlo,Spencer, Robert H.,Kane, Stephanie A.,White, Rebecca B.,Yeh, Suzie,Hartman, George D.,Dinsmore, Christopher J.
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scheme or table
p. 2493 - 2496
(2010/08/06)
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- Metallation of benzylic amines via amine-borane complexes
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Formation of borane complexes of N,N-dimethylbenzylamine, N,N- dimethyl(1-naphthyl)methylamine, N,N-dimethyl(2-naphthyl)methylamine, N- methyltetrahydroisoquinoline and N-methylisoindoline facilitates regioselective metallation of these systems using BuLi, giving intermediate benzylic anions which react with a range of electrophiles to give products in good yield.
- Ebden, Mark R.,Simpkins, Nigel S.,Fox, David N.A.
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p. 12923 - 12952
(2007/10/03)
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- Activation of Benzylic Amines Towards Regioselective Metallation by Borane Complex Formation
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Formation of borane complexes of N,N-dimethylbenzylamine 4 and N-methyltetrahydroisoquinoline 1 facilitates regioselective metallation of these systems using BuLi, giving benzylic anions which react with a range of electrophiles.
- Ebden, Mark R.,Simpkins, Nigel S.,Fox, David N. A.
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p. 8697 - 8700
(2007/10/02)
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