Selectfluor-Induced Oxidative Amination of N-Heteroaromatics with Purine.

An oxidative coupling reaction between purines and aromatic N-heterocycles was developed to synthesize a series of N-heteroaryl purine derivatives using Selectfluor as an oxidant at room temperature. This process uses a commercial oxidant, uses no base, metal, or other additives, is simple to carry out, and has a broad range of substrates.

Visible light-induced direct alkylation of the purine C8-H bond with ethers.

The one-step visible light-induced direct alkylation of the C8-H bond for purine derivatives by ethers was developed using Eosin Y as the photocatalyst and t-BuOOH as the oxidant at room temperature. This method describes the coupling of the α-C of the ether to the C8 of purine. Of particular interest is that substrates include purines with various functional groups and even unprotected 9H-purines. The protocol provides an effective method for the synthesis of 8-alkylpurine derivatives with high atom economy and high regioselectivity.

One-Step Visible Light Photoredox-Catalyzed Purine C8 Alkoxylation with Alcohol.

A cross-dehydrogenation coupling reaction between purines and alcohols, induced by visible light, using an acridinium photocatalyst and air as the sole oxidant, to synthesize a series of C8-alkoxy purine derivatives was developed. This protocol is a green and novel method to construct the C8-O bond on a purine ring with high step and atom economy.

Iodine-catalyzed oxidative functionalization of purines with (thio)ethers or methylarenes for the synthesis of purin-8-one analogues.

An efficient oxidative functionalization of purine-like substrates with (thio)ethers or methylarenes under mild conditions is described. Using I2 as the catalyst, and TBHP as the oxidant, this protocol provides a valuable synthetic tool for the assembly of a wide range of 9-alkyl(benzyl)purin-8-one derivatives with high atom- and step-economy and exceptional functional group tolerance.

Direct Sulfenylation of the Purine C8-H Bond with Thiophenols.

The one-step copper-mediated regioselective formation of the C8-S bond for purine derivatives with arylthiols was achieved using air as the green oxidant in the presence of 1.0 equiv of Na2CO3 and stoichiometric CuCl and 1,10-phenanthroline monohydrate. This method provides an economical, easy-to-handle, and effective method for the synthesis of 8-sulfenylpurine derivatives in moderate to excellent yields. The reaction is selective for C8 over C2 and C6. It also tolerates a free amine on the purine, and it has a wide substrate scope.

C-H Amination of Purine Derivatives via Radical Oxidative Coupling.

An oxidative coupling reaction between purines and alkyl ethers/benzyl compounds was developed to synthesize a series of N9 alkylated purine derivatives using n-Bu4NI as a catalyst and t-BuOOH as an oxidant. This protocol uses commercially available, inexpensive catalysts and oxidants and has a wide range of substrates with a simple operation.

Copper-Catalyzed Cascade Cycloamination of α-Csp(3)-H Bond of N-Aryl Ketimines with Azides: Access to Quinoxalines.

A copper-catalyzed cycloamination of α-Csp(3)-H bond of N-aryl ketimines with sodium azide has been developed. This methodology provides an efficient access to quinoxalines and features mild reaction conditions and readily available ketimines with diverse functional group tolerance.

Copper-Catalyzed Regioselective C-H Sulfonylation of 8-Aminoquinolines.

Copper(I)-catalyzed 5-sulfonation of quinolines via bidentate-chelation assistance has been developed. The reaction is compatible with a wide range of quinoline substrates and arylsulfonyl chlorides. Experimental and theoretical (DFT) investigation implicated that a single-electron-transfer process is involved in this sulfonylation transformation.

Pd(II)-Catalyzed Pyridine N-Oxides Directed Arylation of Unactivated Csp(3)-H Bonds.

A novel Pd(II)-catalyzed pyridine N-oxide directed remote arylation of unactivated Csp(3)-H bonds in aliphatic amides with aryl iodides has been developed. This protocol allows installing various aryl groups at the ß- or γ-Csp(3) atom of alkyl carboxylic acid amides. The key palladabicyclic intermediate of this transformation has been identified by HR-MS and (1)H NMR method.

Highly stereoselective ruthenium(II)-catalyzed direct C2-syn-alkenylation of indoles with alkynes.

A carboamide-directed ruthenium-catalyzed C2-hydroindolation of alkynes has been described. This transformation provides a rapid access to free (N-H) C2-syn-alkenylated indole derivatives with the assistance of copper(II) salts, in which the directing group is removed via a one-pot process.

Ruthenium(II)-catalyzed direct addition of indole/pyrrole C2-H bonds to alkynes.

A ruthenium-catalyzed C2-hydroindolation of alkynes has been achieved. This protocol provides a rapid and concise access to kinds of 2-alkenyl-substituted N-(2-pyridyl)indoles in which the pyridyl moiety can be easily removed to afford free (N-H) indoles under mild conditions. Various arenes and alkynes, including electron-deficient and electron-rich internal alkynes and terminal alkynes, allow for this transformation.

Palladium-catalyzed ortho-functionalization of azoarenes with aryl acylperoxides.

With the aid of an azo directing group, Pd-catalyzed ortho-sp(2) C-H bond activation/functionalization of azoarenes with aryl acyl peroxides has been explored. This transformation provides easy access to regioselectively introducing acyloxyl and aryl groups into azoarenes by simply changing the reaction temperature and solvent.

Palladium-catalyzed cascade oxidation/sp2 C-H acylation of azoarenes with aryl methanes.

A Pd-catalyzed cascade oxidation/sp(2) C-H bond acylation of azoarenes was developed in which readily available aryl methanes were used as the in situ generated acyl sources. This reaction provides a convenient access to ortho-acyl azoarenes under mild conditions.

[Biodegradable plastic production by activated sludge with different carbon sources].

Polyhydroxyalkanoates(PHAs) are polyesters synthesized by numerous bacteria in sludge as intracellular carbon and energy storage compounds under the condition of unbalance growth. Another important aspect of PHAs is thermoplastic polyester with the remarkable characteristics of biodegradability. In this paper, using sodium acetate, sodium propionate and sodium butyrate as the unique carbon source, 5.58%, 3.90% and 4.98% PHAs of dry sludge weight were obtained by assimilated sludge as PHAs synthesis strains in the anaerobic condition, and 12.32%, 9.55% and 11.35% PHAs of dry sludge weight were obtained in the anaerobic condition. It was shown that there were large quantities strains which could accumulate PHAs as granules in the cytoplasm of cells, and the yield of PHAs in the anaerobic process were higher than that in the aerobic process. The best result was that 12.32% PHAs of dry sludge weight was obtained in the best experiment condition, and the yield of the PHAs to substrate was 30.65%. The structures of PHAs were analyzed by 1HNMR spectrum, and the relationship of the structure of PHAs and the carbon source was explained.