Facile Synthesis of Bibenzyl by Reductive Homocoupling of Benzyl Halides in Aqueous Media

A facile synthesis of bibenzyl derivatives by reductive homocoupling reaction is described. Treatment of benzyl halides with metallic iron powder in the presence of a catalytic amount of cuprous salt in aqueous media gives bibenzyls in good yields.     

Iron-catalyzed alkenylation of cyclic ethers via decarboxylative sp(C)–sp(C) coupling

An efficient Fe(acac)₃-catalyzed decarboxylative C(sp²)–C(sp³) coupling reaction via oxidation of C–H bond adjacent to an oxygen atom has been developed successfully, in which cyclic ethers are selectively transformed into the corresponding alkenylation products with good chemical yields and excellent stereoselectivities. The mechanism was studied and the reaction was supposed to proceed through a radical oxidative coupling process.     

芳香化合物直接催化氧化偶联反应研究进展

总结了近年来非官能化芳香化合物直接催化氧化偶联合成联芳香化合物的研究进展,包括芳香化合物的自身偶联、交叉偶联以及分子内偶联反应,同时对反应中涉及的机理也进行了详细地讨论.     

Palladium-catalyzed highly regioselective and stereoselective decarboxylative arylation of unactivated olefins with aryl carboxylic acids

Palladium(II)-catalyzed highly regioselective and stereoselective decarboxylative arylation of unactivated olefins with aryl carboxylic acids has been developed. This method is applicable to a variety of unactivated olefins, including allylamides, long chain functionalized olefins and purely aliphatic olefins, leads to the formation of linear E-configured products in high yields. Both electron-rich and electron-deficient aryl carboxylic acids are suitable arylation reagents. It was found that the choice of solvent, catalyst precursor and oxidant had an important influence on reaction efficiency. As a co-solvent and ligand, DMSO is critical to catalysis. This chemistry expands the scope of decarboxylative arylation of olefins with aryl carboxylic acids, and provides a rapid access to useful linear arylation products of unactivated olefins.     

Decarboxylative bromination of α,β-unsaturated carboxylic acids via an anodic oxidation

A novel bromination of α,β-unsaturated carboxylic acids was developed via a decarboxylation by virtue of a direct anodic electro-oxidation.In this method,ammonium bromide was employed as a bromine source and the reaction features transition-metal-free,short time,and no additional supporting electrolyte.     

A concise synthesis of rooperol and related 1,5-diarylpent-1-en-4-ynes

Two powerful strategies: rapid construction of allylic alkynoates via cyclopropenium ion chemistry and mild, palladium-catalyzed decarboxylative coupling were employed in a concise, 5-steps synthesis of the natural product rooperol. The overall approach allows the preparation of rooperol analogs in as few as 3 steps.     

An alternative CuCl–piperidine‐catalyzed oxidative homocoupling of terminal alkynes affording 1,3‐diynes in air

CuCl with the use of a catalytic amount of piperidine as additive shows high catalytic activity for the oxidative homocoupling reactions of terminal alkynes in toluene at 60 °C in air to afford 1,3‐diynes in high yields. Copyright © 2009 John Wiley & Sons, Ltd.     

Hyperbranched narrow‐bandgap DPP homopolymers synthesized via direct arylation polycondensation

Narrow bandgap and hyperbranched polymers (h‐PTDPP) are synthesized by directly arylation polymerization (DAP) of 2‐bromo‐thiophene‐flanked diketopyrrolopyrrole (Br‐TDPP) as the monomer. Their optical properties as well as chemical structures are studied. The detailed optimization of DAP conditions from catalyst, temperature, solvent, ligand to additive not only leads to high molecular weight h‐PTDPP, but also provides some insight to minimize structural defects in DAP when brominated TDPP is involved as a monomer. The increase in the degree of branching results in lower charge‐carrier mobilities in organic field‐effect transistors involving h‐PTDPP‐3 as the semiconducting channel. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1040–1047     

1,3-Dipolar cycloaddition of stabilised and non-stabilised azomethine ylides derived from uracil polyoxin C (UPoC): access to nikkomycin analogues

Cascade thermal and decarboxylative cycloaddition reactions of uracil polyoxin C (UPoC) with mono- and di-carbonyl compounds in the presence of a dipolarophile leads, via stabilised and non-stabilised azomethine ylides respectively, to a series of polyoxin cycloadducts related to Nikkomycin B in good to excellent yields and high diastereoselectivity.