- Zirconium-hydride-catalyzed site-selective hydroboration of amides for the synthesis of amines: Mechanism, scope, and application
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Developing mild and efficient catalytic methods for the selective synthesis of amines is a longstanding research objective. In this respect, catalytic deoxygenative amide reduction has proven to be promising but challenging, as this approach necessitates selective C–O bond cleavage. Herein, we report the selective hydroboration of primary, secondary, and tertiary amides at room temperature catalyzed by an earth-abundant-metal catalyst, Zr-H, for accessing diverse amines. Various readily reducible functional groups, such as esters, alkynes, and alkenes, were well tolerated. Furthermore, the methodology was extended to the synthesis of bio- and drug-derived amines. Detailed mechanistic studies revealed a reaction pathway entailing aldehyde and amido complex formation via an unusual C–N bond cleavage-reformation process, followed by C–O bond cleavage.
- Han, Bo,Jiao, Haijun,Wu, Lipeng,Zhang, Jiong
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p. 2059 - 2067
(2021/09/02)
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- COMPOUNDS USEFUL AS MODULATORS OF TRPM8
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The present invention includes compounds useful as modulators of TRPM8, such as compounds of Formula (I) and the subgenus and species thereof; personal products containing those compounds; and the use of those compounds and the personal products, particul
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Page/Page column 62; 63
(2012/05/20)
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- Elimination reactions of N-alkyl-N-chlorothenylamines promoted by MeONa-MeOH and Et2NH-MeCN. Effect of the β-aryl group on the imine-forming transition state
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Elimination reactions of N-alkyl-N-chlorothenylamines 1-4 with MeONa-MeOH and Et2NH-MeCN have been studied kinetically. The elimination reactions are regiospecific, producing only the conjugated imines. The reactions are second order and exhibit substantial values of Hammett ρ and k H/kD, and an E2 mechanism is evident. The relative rates of elimination for Me/Et/i-Pr/i-Bu substituents are 1/0.5/0.2/0.02 with MeONa-MeOH and 1/0.4/0.2/0.06 with Et2NH-MeCN. The transition state structure changes toward more product-like as the base is changed from MeONa-MeOH to Et2NH-MeCN. Comparison with existing data reveals that the structure of the transition state is relatively insensitive to the β-aryl group variation.
- Pyun, Sang Yong,Lee, Dong Choon,Seung, Yoon Je,Cho, Bong Rae
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p. 5327 - 5330
(2007/10/03)
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