N-heterocyclic carbene organocatalytic reductive β,β-coupling reactions of nitroalkenes via radical intermediates.
نویسندگان
چکیده
An unprecedented N-heterocyclic carbene catalytic reductive β,β-carbon coupling of α,β-nitroalkenes, by using an organic substrate to mimic the one-electron oxidation role of the pyruvate ferredoxin oxidoreductase (PFOR) in living systems, has been developed. The reaction goes through a radical anion intermediate generated under a catalytic redox process. For the first time, the presence of radical anion intermediate in NHC organocatalysis is observed and clearly verified.
منابع مشابه
Carbene-catalysed reductive coupling of nitrobenzyl bromides and activated ketones or imines via single-electron-transfer process
Benzyl bromides and related molecules are among the most common substrates in organic synthesis. They are typically used as electrophiles in nucleophilic substitution reactions. These molecules can also be activated via single-electron-transfer (SET) process for radical reactions. Representative recent progress includes α-carbon benzylation of ketones and aldehydes via photoredox catalysis. Her...
متن کاملOrganocatalytic activation of alkylacetic esters as enolate precursors to react with α,β-unsaturated imines.
Asymmetric functionalization of alkylacetic esters and their derivatives is traditionally achieved via preformed enolates with chiral auxiliaries. Catalytic versions of such transformations are attractive but challenging. A direct catalytic activation of simple alkylacetic esters via N-heterocyclic carbene organocatalysts to generate chiral enolate intermediates for highly enantioselective reac...
متن کاملN-heterocyclic carbene-catalyzed radical reactions for highly enantioselective β-hydroxylation of enals.
An N-heterocyclic carbene-catalyzed β-hydroxylation of enals is developed. The reaction goes through a pathway involving multiple radical intermediates, as supported by experimental observations. This oxidative single-electron-transfer reaction allows for highly enantioselective access to β-hydroxyl esters that are widely found in natural products and bioactive molecules.
متن کاملCatalytic MBH reaction of β-substituted nitroalkenes with azodicarboxylates.
An unprecedented N-heterocyclic carbene (NHC) catalyzed Morita-Baylis-Hillman (MBH) reaction of β-substituted nitroalkenes and azodicarboxylates has been developed. Both β-aryl and β-alkyl nitroalkenes worked well for the reaction using 5 mol% of NHC catalyst, giving the desired α-hydrazino-α,β-unsaturated nitroalkenes in good to excellent yields.
متن کاملEnantioselective activation of stable carboxylate esters as enolate equivalents via N-heterocyclic carbene catalysts.
The first N-Heterocyclic Carbene (NHC) mediated activation of stable carboxylate esters to generate enolate intermediates is disclosed. The catalytically generated arylacetic ester enolates undergo enantioselective reactions with α,β-unsaturated imines.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Organic letters
دوره 16 21 شماره
صفحات -
تاریخ انتشار 2014