Low-valent Titanium Induced Reductive Coupling Reaction of Aryl Sulfonyl Chlorides with α,β-Unsaturated Esters

The reductive coupling reactions of aryl sulfonyl chloride induced by (TiCl4-Zn) reagent affords diaryl disulfide. However, reaction of aryl sulfonyl chloride with α,β-unsaturated ester under the same condition affords β-arylsulfo ester.

Facile and Cost-Efficient Synthesis of Photovoltaic Polymers via Direct Arylation Coupling

As the high calibre candidate of lightweight and flexible solar cells,polymer solar cells(PSCs)have made tremendous progress in recent years.However,the active photovoltaic materials in PSCs are mainly synthesized by metal-mediated coupling reaction requiring harsh reaction conditions,multiple-step synthesis,and cumbersome purification,which is not cost-efficient and may bring toxicity concerns.It is not favorable to the production of photovoltaic polymers and PSC devices on a large scale,and therefore unsuitable for the PSCs industrialization.Direct arylation coupling reaction via aromatic C―H bonds activation enables the synthesis of conjugated polymers under mild conditions and simultaneously reduces synthetic steps,difficulty,and toxic reaction byproducts.This review provides an overview of the history of preparing representative photovoltaic polymers utilized in PSCs through direct arylation reactions and discusses the activity and selectivity of C―H bonds in typical building blocks under different reaction conditions.Especially,the impact of direct arylation condition on defect formation and photovoltaic performance of the photovoltaic polymers is addressed and compared with conventional Stille coupling methods.

Competitive coupling of amide anion over menthyl propionate anion with aryl radical

A competitive coupling of amide anion over menthyl propionate anion with aryl radical in photo-S_(RN) 1 mechanism was encountered. The rcaction afforded N-aryl propionic amide in excel- lent yield. In contrast, the expected nucleophilic photo-S_(RN) 1 substitution originating from the carb- anion was observed in the case of t-butyl propionate. According to the proposed mechanisms and MO correlation diagrams of the coupling step of nucleophiles with aryl radical, the interesting con- trast is reasonably attributed to the variation in energy gap between π~*c-o and π~*Ar of (ArNu)- Usually, the odd electron of (ArNu)- is weightly populated at π~*c-o, however, the diminished priv- ilege of π~*c-o in menthyl propionate promotes a dominant population of the odd electron at π~*Ar, which leads to the fragmentation of (ArNu)- into the starting carbanion and aryl radical.

C–H Arylation using acyl thiourea ligands: Applications in the synthesis of 3,6-diaryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles

Synthesis of a series of new 3,6-diaryl-[1,2,4]triazolo[3,4-b] [1,3,4]thiadiazoles（5a-o） was achieved by phophine free, C-H arylative cross-coupling of 6-aryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles（4a-o）with suitably substituted iodoanilines using 1-（2-naphthoyl）-3-（4-bromophenyl）thiourea as a ligand.The requisite triazolothiadiazoles（4a-o） were obtained by the condensation of 4-amino-1,2,4-triazole-3-thiol（3） with suitably substituted aromatic acids in the presence of phosphoryl chloride.

Manganese (Ⅲ) Acetate:A Versatile Reagent in Organic Chemistry

1 Results Free radical reactions have become increasingly important,as well as a very attractive tool,in organic synthesis within the last two decades,due to their powerful,selective,specific,and mild reaction abilities.Mn(OAc)3 mediated oxidative free radical reactions have been extensively developed in the last twenty years[1,6].Numerous regio-,chemo-,and stereoselective synthetic methods have been developed in both inter-and intramolecular reactions,and have detailed the progress of Mn(OAc)3 mediated...

Palladium-catalyzed amination of chloro-substituted 5-nitropyrimidines with amines

A concise and efficient approach was developed for the synthesis of mono-substituted and di-substituted pyrimidines products via palladium-catalyzed amination of chloro-substituted 5-nitropyrimidines and amines. This synthetic methodology can produce various di-substituted pyrimidines in high yields with good functional group tolerance, and provide a complementary tool for the syntheses of important intermediates of nucleosides and purines with bioactivities.