- A general and practical sulfonylation of benzylic ammonium salts with sulfonyl hydrazides for the synthesis of sulfones
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A practical and efficient approach adopting transition-metal-free cross-coupling of sulfonyl hydrazides with benzyl ammonium salts has been developed to synthesize benzyl sulfones using Cs2CO3 as base under mild conditions. The protocol employs stable and easy to handle coupling partners, and is endowed with good substrate compatibility, leading to functional benzyl sulfones in good yields.
- Zhu, Haibo,Zhang, Yingying,Liu, Yishuai,Yang, Liu,Xie, Zongbo,Jiang, Guofang,Le, Zhang-Gao
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supporting information
(2020/05/06)
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- Ni-Catalyzed Iterative Alkyl Transfer from Nitrogen Enabled by the in Situ Methylation of Tertiary Amines
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Current methods to achieve transition-metal-catalyzed alkyl carbon-nitrogen (C-N) bond cleavage require the preformation of ammonium, pyridinium, or sulfonamide derivatives from the corresponding alkyl amines. These activated substrates permit C-N bond cleavage, and their resultant intermediates can be intercepted to affect carbon-carbon bond-forming transforms. Here, we report the combination of in situ amine methylation and Ni-catalyzed benzalkyl C-N bond cleavage under reductive conditions. This method permits iterative alkyl group transfer from tertiary amines and demonstrates a deaminative strategy for the construction of Csp3-Csp3 bonds. We demonstrate PO(OMe)3 (trimethylphosphate) to be a Ni-compatible methylation reagent for the in situ conversion of trialkyl amines into tetraalkylammonium salts. Single, double, and triple benzalkyl group transfers can all be achieved from the appropriately substituted tertiary amines. Transformations developed herein proceed via recurring events: The in situ methylation of tertiary amines by PO(OMe)3, Ni-catalyzed C-N bond cleavage, and concurrent Csp3-Csp3 bond formation.
- Nwachukwu, Chideraa Iheanyi,McFadden, Timothy Patrick,Roberts, Andrew George
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p. 9979 - 9992
(2020/09/03)
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- 8-(4-Methoxyphenyl)pyrazolo[1,5-a]-1,3,5-triazines: Selective and centrally active corticotropin-releasing factor receptor-1 (CRF1) antagonists
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This report describes the syntheses and structure-activity relationships of 8-(4-methoxyphenyl)pyrazolo-[1,5-a]-1,3,5-triazine corticotropin releasing factor receptor-1 (CRF1) receptor antagonists. CRF1 receptor antagonists may be potential anxiolytic or antidepressant drugs. This research culminated in the discovery of analogue 12-3, which is a potent, selective CRF1 antagonist (hCRF1 IC50 ) 4.7 ± 2.0 nM) with weak affinity for the CRF-binding protein and biogenic amine receptors. This compound also has a good pharmacokinetic profile in dogs. Analogue 12-3 is orally effective in two rat models of anxiety: the defensive withdrawal (situational anxiety) model and the elevated plus maze test. Analogue 12-3 has been advanced to clinical trials.
- Gilligan, Paul J.,He, Liqi,Clarke, Todd,Tivitmahaisoon, Parcharee,Lelas, Snjezana,Li, Yu-Wen,Heman, Karen,Fitzgerald, Lawrence,Miller, Keith,Zhang, Ge,Marshall, Anne,Krause, Carol,McElroy, John,Ward, Kathyrn,Shen, Helen,Wong, Harvey,Grossman, Scott,Nemeth, Gregory,Zaczek, Robert,Arneric, Stephen P.,Hartig, Paul,Robertson, David W.,Trainor, George
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scheme or table
p. 3073 - 3083
(2010/01/16)
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- CYCLISATION DE DIARYLALCANES EN MILIEU SUPERACIDE: SYNTHESE DE CETONES TRICYCLIQUES A METHYLE ANGULAIRE ET MECANISME DE LEUR ISOMERISATION
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Cyclisation of redily available diaryl-1,2 ethanes 1-4 proceeds in SbF5-HF at 0oC to yield tricyclic phenantrenones 5,6,7 and 11 bearing an angular methyl group.This process implies the electrophilic attack of the more basic aromatic ring, reacting through its disprotonated form (on the oxygen and the meta carbon atom) on the second aromatic ring.Isomerization of these primary products may be observed (to give ketones 8,9,10 from 3 and 12 from 4) and it has been demonstrated by the use of specifically deuterated 3d that it involves stereospecific 1,2 hydride (or deuteride) shifts, without exchange.
- Berrier, C.,Jacquesy, J. C.,Gesson, J. P.,Renoux, A.
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p. 1983 - 1994
(2007/10/02)
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