Depleting oil reserves and growing environmental concerns have necessitated the development of sustainable processes to fuels and chemicals. Here we have developed a general metabolic platform in E. coli to biosynthesize carboxylic acids. By engineering selectivity of 2-ketoacid decarboxylases and screening for promiscuous aldehyde dehydrogenases, synthetic pathways were constructed to produce both C5 and C6 acids. In particular, the production of isovaleric acid reached 32 g/L (0.22 g/g glucose yield), which is 58% of the theoretical yield. Furthermore, we have developed solid base catalysts to efficiently ketonize the bio-derived carboxylic acids such as isovaleric acid and isocaproic acid into high volume industrial ketones: methyl isobutyl ketone (MIBK, yield 84%), diisobutyl ketone (DIBK, yield 66%) and methyl isoamyl ketone (MIAK, yield 81%). This hybrid "Bio-Catalytic conversion" approach provides a general strategy to manufacture aliphatic ketones, and represents an alternate route to expanding the repertoire of renewable chemicals.
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http://dx.doi.org/10.1038/srep00311 | DOI Listing |
Anal Chim Acta
February 2025
Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt. Electronic address:
Background: The current synthetic strategies for carbon dots (CDs) are usually time-consuming, rely on complicated processes, and need high temperatures and energy. Recent studies have successfully synthesized CDs at room temperature. Unfortunately, most CDs synthesized at room temperature are obtained under harsh reaction conditions, prepared using aromatic precursors, or need a long time to generate.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram 695551, Kerala, India.
Herein, we report a formal C-C bond azidation and cyanation of unactivated aliphatic ketones using commercially available tosyl azide and cyanide, respectively. A visible-light-mediated organophotocatalyst enables radical azidation and cyanation of ketone-derived pro-aromatic dihydroquinazolinones (under mostly redox-neutral conditions) as supported by preliminary mechanistic studies. These metal-free and scalable protocols can be used to synthesize tertiary, secondary, and primary alkyl azides and nitriles with good functional group tolerance and postsynthetic diversification of the azide group, including bioconjugation.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee-247667, Uttarakhand, India.
Ni(II)-hydrazineylpyridine (Ni(II)-PyH)-catalyzed regioselective synthesis of α-benzyl substituted β-hydroxy ketones from α,β-unsaturated ketones and alcohols is reported a Fenton free-radical reaction. This protocol enables facile access to desired products in good to excellent yields in 12 h using toluene solvent at room temperature to 100 °C. The structural analysis of the products was confirmed by H, C-NMR, GC-MS, and HRMS data.
View Article and Find Full Text PDFNature
January 2025
Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA.
C-H activation is the most direct way of functionalizing organic molecules. Many advances in this field still require specific directing groups to achieve the necessary activity and selectivity. Developing C-H activation reactions directed by native functional groups is essential for their broad application in synthesis.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095-1569, United States.
The homolytic cleavage of C-C bonds adjacent to specific functional groups has lately emerged as a versatile approach for molecular diversification. Despite the ubiquity and synthetic utility of ketones, radical fragmentation of their α-C-C bonds has proven to be a formidable challenge. Here, we present a broadly applicable deacylative strategy designed to homolytically cleave aliphatic ketones of various complexities, including transformations of cycloalkanones into carboxylic acids tethered to C-centered free radicals that can be engaged in diverse radical-based processes.
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