The one‐electron reduction (OER) can profoundly affect the structure and reactivity of organic compounds. OER induced radical decarboxylative functionalizations of redox‐active esters have gained ...wide concerns in this century. In this review, we present recent advances using redox‐active esters as carbon‐centered radical precursors to form carbon–carbon and carbon–heteroatom bonds.
Radical decarboxylative functionalization of redox‐active esters induced by one‐electron reductions (OER) has recently become a research focus in synthetic chemistry. Here we present the new advances using redox‐active esters as carbon‐centered radical precursors to form carbon–carbon and carbon–heteroatom bonds.
Auto-Oxidative Coupling of Glycine Derivatives Huo, Congde; Yuan, Yong; Wu, Mingxia ...
Angewandte Chemie (International ed.),
December 1, 2014, Letnik:
53, Številka:
49
Journal Article
Recenzirano
The unprecedented title reaction between glycine derivatives and indoles, as well as the auto‐oxidative Povarov/aromatization tandem reaction of glycine derivatives with olefins are described. The ...reactions were performed in the absence of redox‐active catalysts and chemical oxidants under mild reaction conditions. Only simple organic solvents and air (or O2) were required.
Aired out: The unprecedented title reaction between glycine derivatives and indoles, as well as the auto‐oxidative Povarov/aromatization tandem reaction of glycine derivatives with olefins are described. The reactions were performed in the absence of redox‐active catalysts and chemical oxidants under mild reaction conditions. Only simple organic solvents and air (or O2) were required.
A novel CBr4‐mediated dehydrogenative Povarov/aromatization tandem reaction of glycine derivatives with alkenes, leading to complex quinoline derivatives, and a CBr4‐mediated dehydrogenative CH ...functionalization of N‐aryl tetrahydroisoquinolines with nucleophiles to form CC and CP bonds are reported. The reactions were performed under very simple and mild reaction conditions; only CBr4 was used as a promoter. A plausible mechanism involving a radical process is proposed.
Go tandem! A novel CBr4‐mediated dehydrogenative Povarov/aromatization tandem reaction of glycine derivatives with alkenes and CBr4‐mediated dehydrogenative CH functionalization of N‐aryl tetrahydroisoquinolines is reported. The reactions were performed under simple and mild conditions, only CBr4 and a solvent are required (see scheme). A plausible mechanism involving a radical process is also proposed.
A simple and practical carbon tetrabromide promoted intramolecular aerobic oxidative dehydrogenative coupling reaction has been developed to provide a straightforward ring closure protocol for ...2-aryloxybenzaldehydes to furnish xanthones. The reaction was performed under metal-, additive- and solvent-free conditions with good tolerance of functional groups. The present method is also applicable to the synthesis of fluorenones by using 2-arylbenzaldehydes as substrates. Preliminary studies of the reaction mechanism indicated that the reaction may proceed through a radical pathway.
A simple and efficient copper(I) chloride‐catalyzed aerobic oxidative coupling of glycine derivatives (glycine esters, glycine amides and short peptides) with indoles has been developed. The reaction ...is performed in the absence of any other additives under mild conditions and only requires simple copper salts as a catalyst and oxygen as a co‐oxidant.
A visible-light photoinduced ring opening of N -alkyl-4-piperidinols under mild conditions has been achieved. The reaction sequence involves a visible-light-induced charge-transfer complex, which ...promoted the S–Cl bond cleavage of sulfonyl chlorides. The generated sulfonyl radical further reacts with N -alkyl-4-piperidinol cation radicals to achieve C–N and C–C bond cleavages to yield homoallylamine products.
Triarylaminium salt was disclosed as an efficient initiator for the novel Friedel–Crafts alkylation/annulation cascade reaction between chalcone epoxides and 2-naphthols to construct polysubstituted ...1,2-dihydronaphtho2,1-bfurans. The DDQ/NaNO2/O2 catalytic system was first applied to the aerobic oxidative aromatization of heterocycles, and a simple and efficient one-pot tandem FC alkylation/annulation/aerobic oxidative aromatization procedure was also developed for the synthesis of complex naphtho2,1-bfurans.
The most abundant and biologically active green tea catechin, (-)-epigallocatechin-3-gallate or (-)-EGCG, has been shown to act as a proteasome inhibitor and tumor cell death inducer. However, ...(-)-EGCG is unstable under physiologic conditions and has poor bioavailability. Previously, in an attempt to increase the stability of (-)-EGCG, we introduced peracetate protections to its reactive hydroxyl groups and showed that this peracetate-protected (-)-EGCG Pro-EGCG (1); formerly named compound 1 could be converted into (-)-EGCG under cell-free conditions. In the current study, we provide evidence that when cultured human breast cancer MDA-MB-231 cells were treated with Pro-EGCG (1), (-)-EGCG was not only converted but also accumulated, accompanied by enhanced levels of proteasome inhibition, growth suppression, and apoptosis induction, compared with cells treated with natural (-)-EGCG. To investigate the potential use of Pro-EGCG (1) as a novel prodrug that converts to a cellular proteasome inhibitor and anticancer agent in vivo, MDA-MB-231 tumors were induced in nude mice, followed by treatment with Pro-EGCG (1) or (-)-EGCG for 31 days. Results of this in vivo study showed a significant inhibition of breast tumor growth by Pro-EGCG (1), compared with (-)-EGCG, associated with increased proteasome inhibition and apoptosis induction in tumor tissues. In conclusion, we have shown that Pro-EGCG (1) increases the bioavailability, stability, and proteasome-inhibitory and anticancer activities of (-)-EGCG in human breast cancer cells and tumors, suggesting its potential use for cancer prevention and treatment.
A fragment‐reassembly strategy was applied to the construction of 1,4‐dihydropyridines and phosphorus‐substituted 1,4‐dihydropyridines under catalytic radical cation salt‐induced C(sp)3H ...functionalization of glycine derivatives. Mechanistic studies show that domino C(sp)3H bond oxidation and CN bond cleavage reactions are involved.
A new protocol for the NiC12-catalyzed cross-electrophile coupling of aryl bromides with pyrimidin-2-yl tosyl- ates to give the corresponding C2-arylation pyrimidine derivatives has been developed. ...This study provides an improvement over previous methods by using pyrimidin-2-yl tosylates instead of halides as coupling partners that are stable and easily available.
PDF
