Copper-mediated oxygenation of aldehydes and internal Cannizzaro-like rearrangement of phenylglyoxal

Computational exploration of copper catalyzed vinylogous aerobic oxidation of unsaturated compounds

“…Following the deprotonation step, the molecular oxygen approaches the Cu II center and attacks the C γ of E-1a substrate in a concerted manner via a six-membered chair-like transition state (TS2, Fig. 2) which leads to a peroxide bridge between Cu and substrate [52][53][54][55] To understand the regioselectivity, the formation of α-hydroxylated product by the oxygen addition at the α-carbon via transition state α-TS2 was also calculated (Figure S1). The free energy of α-TS2 is 1.3 kcal/mol higher than that of TS2 which leads to the γ-hydroxylated product, in line with the experimental observation that γ-hydroxylated product is more favorable.…”

Initiator selectivity during free radical copolymerizations of styrene and methyl methacrylate initiated by anaerobic copper(II) oxidation of carbon‐13 labeled acetophenone

“…In the present study, 13 C-labeled phenacyl radicals were generated by use of a combination of 13 C-labeled acetophenone, triethylamine, triphenylphosphine, cupric octanoate, and pyridine in benzene solution. It is believed that acetophenone is oxidized in the enolic form by a complex formed in situ from cupric octanoate, pyridine, and triphenylphosphine 22,[25][26][27] As shown in Scheme 1, the enolate radicals then react with styrene or methyl methacrylate to form initiating radicals with 13 C labeled chain ends. Copolymeric initiating radicals can also be produced by varying the feed ratios in mixtures of styrene and MMA.…”

“…[11][12][13][14][15][16][17][18][19][20][21] In this article, we discuss the NMR spectra of polymers initiated by 13 C-enriched phenacyl radicals. Goodrich [22][23][24] has shown that phenacyl and other carbonyl group-containing radicals, generated by anaerobic oxidation of aldehydes and ketones, [25][26][27] can be used to initiate polymerizations and copolymerizations and for block and graft copolymer syntheses. The 13 C-NMR spectra of the polymer chain ends consisted of multiple resonances that reflected the effects of stereosequences as large as tetrads in the case of some homopolymers and also allowed the nature of the monomer units attached to the initiator fragments to be identified.…”

Preparation of triazole-linked glycosylated α-ketocarboxylic acid derivatives as new PTP1B inhibitors

“…Notably, the relatively low yields of the obtained glycosyl a-ketocarboxylic acids (52% for 15 and 50% for 19) was most likely rendered by partial conversion of the ketoacids into carboxylic acids in basic condition. 19 Next, the inhibitory activity of the prepared glycosides (10)(11)(12)(13)(14)(15)(16)(17)(18)(19) as well as the azido a-ketocarboxylic acid 7 was assayed toward PTP1B. The recombinant human PTP1B was first expressed and purified.…”