The first example of oxidative C−H fluoroalkoxylation of quinoxalinones with fluoroalkyl alcohols under transition-metal and solvent-free conditions is described. This approach provides the synthesis of fluoroalkoxylated quinoxaline derivatives with good to excellent yields under mild reactions conditions. This method can also be extended to the facile and efficient synthesis of histamine-4 receptor.F luorine-containing molecules have found important applications in drug discovery, agricultural chemicals, and materials science. 1 Fluoroalkoxyl aryl ethers are among those that have received much attention, because of the unique properties such as good electron-withdrawing effect and the significant lipophilicity of the fluoroalkoxyl group (Scheme 1). 2

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We herein describe a B2Pin2-assisted copper-catalyzed semihydrogenation of alkynes. A variety of alkenes were obtained in good to excellent yields with Z-selectivity under mild reaction conditions. Mechanistic studies indicated that a transfer hydrogenation process was involved and ethanol acted as both a solvent and a hydrogen donor in this reaction. The present protocol enabled convenient synthesis of deuterium-substituted Z-alkenes such as Z-Combretastain A4-d 2 in a high deuteration ratio by using readily available ethanol-d 1 as the deuterium source.

A deoxygenative radical alkylation of aromatic alkynes with alkyl aldehydes for the preparation of allylarenes has been successfully achieved. This transformation is accomplished through the reaction of alkyl aldehydes with alkynes in the presence of dipropylamine and Hantzsch ester catalyzed by a P/N heteroleptic Cu­(I)-based photosensitizer under photoredox catalysis conditions. Preliminary mechanistic studies reveal that this aldehyde–alkyne coupling process comprises a regioselective radical addition of in situ-generated alkyl-substituted α-amino radicals to alkynes with subsequent 1,5-proton transfer, C–N bond cleavage, and concomitant isomerization of the resulting allyl radical species. Thus, in net result, dipropylamine serves as a traceless linker agent for the deoxygenative radical cross-coupling of alkyl aldehydes with alkynes under photoredox catalysis reaction conditions.

An unprecedented exploration of tertiary amines as alkyl radical equivalents for cross-coupling with aromatic alkynes to access allylarenes has been achieved by a P/N heteroleptic Cu(I)based photosensitizer under photoredox catalysis conditions. Mechanistic studies reveal that the reaction might undergo radical addition of in situ-generated α-amino radical intermediates to alkynes followed by 1,5-hydrogen transfer, C−N bond cleavage, and concomitant isomerization of the resulting allyl radical species.