This content will become publicly available on May 16, 2024
- Award ID(s):
- 2052611
- NSF-PAR ID:
- 10425312
- Date Published:
- Journal Name:
- Sustainable Energy & Fuels
- Volume:
- 7
- Issue:
- 10
- ISSN:
- 2398-4902
- Page Range / eLocation ID:
- 2339 to 2348
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
The selective cleavage of C–C/C–O linkages represents a key step toward achieving the chemical conversion of biomass to targeted value-added chemical products under ambient conditions. Using photoelectrosynthetic solar cells is a promising method to address the energy intensive depolymerization of lignin for the production of biofuels and valuable chemicals. This feature article gives an in-depth overview of recent progress using dye-sensitized photoelectrosynthetic solar cells (DSPECs) to initiate the cleavage of C–C/C–O bonds in lignin and related model compounds. This approach takes advantage of N -oxyl mediated catalysis in organic electrolytes and presents a promising direction for the sustainable production of chemicals currently derived from fossil fuels.more » « less
-
In the past several years, tremendous advances have been made in non-classical routes for amide bond formation that involve transamidation and amidation reactions of activated amides and esters. These new methods enable the formation of extremely valuable amide bonds via transition-metal- catalyzed, transition-metal-free or metal-free pathways by exploiting chemoselective acyl C–X (X = N, O) cleavage under mild conditions. In a broadest sense, these reactions overcome the formidable challenge of activating C–N/C–O bonds of amides or esters by rationally tackling nN→π*C=O delocalization in amides and nO→π*C=O donation in esters. In this account, we summarize the recent remarkable advances in the development of new methods for the synthesis of amides with a focus on (1) transition-metal/NHC- catalyzed C–N/C–O bond activation, (2) transition-metal-free highly selective cleavage of C–N/C–O bonds, (3) the development of new acyl-transfer reagents, and (4) other emerging methods.more » « less
-
Abstract Although cross‐coupling reactions of amides by selective N−C cleavage are one of the most powerful and burgeoning areas in organic synthesis due to the ubiquity of amide bonds, the development of mechanochemical, solid‐state methods remains a major challenge. Herein, we report the first mechanochemical strategy for highly chemoselective, solvent‐free palladium‐catalyzed cross‐coupling of amides by N−C bond activation. The method is conducted in the absence of external heating, for short reaction time and shows excellent chemoselectivity for σ N−C bond activation. The reaction shows excellent functional group tolerance and can be applied to late‐stage functionalization of complex APIs and sequential orthogonal cross‐couplings exploiting double solventless solid‐state methods. The results extend mechanochemical reaction environments to advance the chemical repertoire of N−C bond interconversions to solid‐state environmentally friendly mechanochemical methods.
-
Abstract Although cross‐coupling reactions of amides by selective N−C cleavage are one of the most powerful and burgeoning areas in organic synthesis due to the ubiquity of amide bonds, the development of mechanochemical, solid‐state methods remains a major challenge. Herein, we report the first mechanochemical strategy for highly chemoselective, solvent‐free palladium‐catalyzed cross‐coupling of amides by N−C bond activation. The method is conducted in the absence of external heating, for short reaction time and shows excellent chemoselectivity for σ N−C bond activation. The reaction shows excellent functional group tolerance and can be applied to late‐stage functionalization of complex APIs and sequential orthogonal cross‐couplings exploiting double solventless solid‐state methods. The results extend mechanochemical reaction environments to advance the chemical repertoire of N−C bond interconversions to solid‐state environmentally friendly mechanochemical methods.
-
Benzylic alcohols are among the most important intermediates in organic synthesis. Recently, the use of abundant metals has attracted significant attention due to the issues with the scarcity of platinum group metals. Herein, we report a sequential method for the synthesis of benzylic alcohols by a merger of iron catalyzed cross-coupling and highly chemoselective reduction of benzamides promoted by sodium dispersion in the presence of alcoholic donors. The method has been further extended to the synthesis of deuterated benzylic alcohols. The iron-catalyzed Kumada cross-coupling exploits the high stability of benzamide bonds, enabling challenging C(sp2)–C(sp3) cross-coupling with alkyl Grignard reagents that are prone to dimerization and β-hydride elimination. The subsequent sodium dispersion promoted reduction of carboxamides proceeds with full chemoselectivity for the C–N bond cleavage of the carbinolamine intermediate. The method provides access to valuable benzylic alcohols, including deuterium-labelled benzylic alcohols, which are widely used as synthetic intermediates and pharmacokinetic probes in organic synthesis and medicinal chemistry. The combination of two benign metals by complementary reaction mechanisms enables to exploit underexplored avenues for organic synthesis.more » « less