| Reference | [1]. Chemistry. 2019 Sep 25;25(54):12517-12520. doi: 10.1002/chem.201903668. Epub 2019 Sep 4.<br />
Vinyl Triflate-Aldehyde Reductive Coupling-Redox Isomerization Mediated by Formate: Rhodium-Catalyzed Ketone Synthesis in the Absence of Stoichiometric Metals.<br />
Shuler WG(1), Swyka RA(1), Schempp TT(1), Spinello BJ(1), Krische MJ(1).<br />
Author information: (1)University of Texas at Austin, Department of Chemistry, 105 E 24th St. (A5300), Austin, TX, 78712-1167, USA.<br />
Direct conversion of aldehydes to ketones is achieved via rhodium-catalyzed vinyl triflate-aldehyde reductive coupling-redox isomerization mediated by potassium formate. This method circumvents premetalated C-nucleophiles and discrete redox manipulations typically required to form ketones from aldehydes.<br />
DOI: 10.1002/chem.201903668 PMCID: PMC6763374 PMID: 31403727<br />
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[2]. J Am Chem Soc. 2019 May 1;141(17):6864-6868. doi: 10.1021/jacs.9b03113. Epub 2019 Apr 18.<br />
Conversion of Aldehydes to Branched or Linear Ketones via Regiodivergent Rhodium-Catalyzed Vinyl Bromide Reductive Coupling-Redox Isomerization Mediated by Formate.<br />
Swyka RA(1), Shuler WG(1), Spinello BJ(1), Zhang W(1), Lan C(1), Krische MJ(1).<br />
Author information: (1)Department of Chemistry , University of Texas at Austin , Austin , Texas 78712 , United States.<br />
A regiodivergent catalytic method for direct conversion of aldehydes to branched or linear alkyl ketones is described. Rhodium complexes modified by P tBu2Me catalyze formate-mediated aldehyde-vinyl bromide reductive coupling-redox isomerization to form branched ketones. Use of the less strongly coordinating ligand, PPh3, promotes vinyl- to allylrhodium isomerization en route to linear ketones. This method bypasses the 3-step sequence often used to convert aldehydes to ketones involving the addition of pre-metalated reagents to Weinreb or morpholine amides.<br />
DOI: 10.1021/jacs.9b03113 PMCID: PMC6602061 PMID: 30998328 [Indexed for MEDLINE]<br />
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[3]. Phys Chem Chem Phys. 2020 Jan 2;22(2):446-454. doi: 10.1039/c9cp05030b.<br />
Observation of hydroperoxyethyl formate from the reaction between the methyl Criegee intermediate and formic acid.<br />
Cabezas C (1), Endo Y .<br />
Author information: (1)Department of Applied Chemistry, Science Building II, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan. [email protected].<br />
Rapid reactions of carboxylic acids with Criegee intermediates provide efficient gas phase removal processes and are proposed to trigger the formation of new molecular compounds, which are implicated in the growth of atmospheric aerosols. The new adducts formed in these reactions are known as hydroperoxide esters and are predicted to be condensable, with lower vapor pressures than the reactants. We report here the direct detection of hydroperoxyethyl formate (HOOCH(CH3)OCHO) formed in the gas phase reaction between the methyl substituted Criegee intermediate, CH3CHOO, and formic acid. Two different isomers of this hydroperoxide ester have been observed using the combination of pulsed Fourier-transform microwave spectroscopy with isotopic substitution experiments and high-level quantum chemical calculations. The identification of hydroperoxyethyl formate as the main nascent product of the CH3CHOO and HCOOH reaction differs from previous results that reported the formation of vinyl hydroperoxide as the reaction product of this reaction.<br />
DOI: 10.1039/c9cp05030b PMID: 31746865<br />
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[4]. ACS Appl Mater Interfaces. 2019 Feb 20;11(7):6881-6889. doi: 10.1021/acsami.8b11845. Epub 2019 Feb 6.<br />
Promoter Effects of Functional Groups of Hydroxide-Conductive Membranes on Advanced CO(2) Electroreduction to Formate.<br />
Wang M(1), Preston N(2), Xu N(1), Wei Y(1), Liu Y(3), Qiao J(1)(4).<br />
Author information: (1)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, State Environmental Protection Engineering Center for Pollution Treatment and Contro in Textile Industry, College of Environmental Science and Engineering , Donghua University , 2999 Ren'min North Road , Shanghai 201620 , China. (2)Department of Chemical Engineering , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada. (3)Institute of Sustainable Energy , Shanghai University , 99 Shangda Road , Shanghai 200444 , China. (4)Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , China.<br />
The electrochemical reduction of CO2 at ambient conditions provides a latent solution of turning waste greenhouse gases into commodity chemicals or fuels; however, a satisfactory ion-conducting membrane for maximizing the performance of a CO2 electrolyzer has not been developed. Here, we report the synthesis of a sequence of hydroxide-conductive polymer membranes, which are based on polymer composites of poly(vinyl alcohol)/Guar hydroxypropyltrimonium chloride, for use in CO2 electrolysis. The effect of different membrane functional groups, including thiophene, hydroxybenzyl, and dimethyloctanal, on the efficiency and selectivity of CO2 electroreduction to formate is thoroughly evaluated. The membrane incorporating thiophene groups exhibits the highest Faradaic efficiency of 71.5% at an applied potential of -1.64 V versus saturated calomel electrode (SCE) for formate. In comparison, membranes containing hydroxybenzyl and dimethyloctanal groups produced lower efficiencies of 67.6 and 68.6%, respectively, whereas the commercial Nafion 212 membrane was only 57.6% efficient. The improved efficiency and selectivity of membranes containing thiophene groups are attributed to a significantly increased hydroxide conductivity (0.105 S cm-1), excellent physicochemical properties, and the simultaneous attenuation of formate product crossover.<br />
DOI: 10.1021/acsami.8b11845 PMID: 30676728<br />
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[5]. Ushakov, S.N., Ivanov, S.S. Copolymerization of butadiene with vinyl formate.<br />
Russ Chem Bull 6, 1486–1492 (1957). https://doi.org/10.1007/BF01169753
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