An electron donor-acceptor photoactivation strategy for the synthesis of S-aryl dithiocarbamates using thianthrenium salts under mild aqueous micellar conditions

An eco-friendly and convenient method is developed herein for the synthesis of S-aryl dithiocarbamates via visible-light-induced SET process of an EDA complex between thianthrenium salt functionalized arenes and dithiocarbamate anions under mild aqueous micellar conditions.This strategy indirectly realizes the method for constructing S-aryl dithiocarbamates through site-selective C−H functionalization of arenes.Most importantly,the reaction proceeded smoothly without addition of any photocatalyst,and the by-product thianthrene is recycled in quantity,ultimately minimizing the production of chemical waste.This protocol provides a promising synthesis candidate for the construction of valuable S-aryl dithiocarbamates,which also opens up a new avenue for micellar photocatalysis.

Anti-Markovnikov ring-opening of sulfonium salts with alkynes by visible light/copper catalysis

Internal alkynes are widespread skeletons in bioactive molecules and materials which are also used as important building blocks in chemical synthesis. Herein, we report a novel and efficient copper-catalyzed Sonogashira reaction between sulfonium salts and alkynes through an anti-Markovnikov ring-opening pathway promoted by visible light. The coexistence of the nitrogen and phosphorus ligands in the system is the key to the success of this reaction. This radical type ring-opening reaction affords a new strategy for the synthesis of internal alkynes. Furthermore, this study is also an effective complement to the diverse reaction patterns of sulfonium salts.

Rapid formation of Csp^(3)–Csp^(3) bonds through copper-catalyzed decarboxylative Csp^(3)–H functionalization

Transition-metal-catalyzed decarboxylative and C–H functionalization strategy for the construction of Csp^(2)-Csp^(2),Csp^(2)-Csp,and Csp^(2)-Csp^(3) bonds has been extensively studied.However,research surveys of this synthetic strategy for the Csp^(3)-Csp^(3) bond forming reactions are surprisingly scarce.Herein,we present an efficient approach for the rapid formation of Csp^(3)–Csp^(3) bond through copper-catalyzed decarboxylative Csp^(3)–H functionalization.The present method should provide a useful access to C3-substituted indole scaffolds with possible biological activities.Mechanistic experiments and DFT calculations supported a dual-Cu(Ⅱ)-catalytic cycle involving rate-determining decarboxylation in an outer-sphere radical pathway and spin-crossover-promoted C–C bond formation.This strategy offers a promising synthesis method for the construction of Csp^(3)–Csp^(3) bond in the field of synthetic and pharmaceutical chemistry and extends the number of still limited copper-catalyzed decarboxylative Csp^(3)–Csp^(3) bond forming reaction.

Visible-light-induced regioselective cross-dehydrogenative coupling of 2-isothiocyanatonaphthalenes with amines using molecular oxygen

An efficient and eco-friendly protocol for the construction of naphtho[2,1-d]thiazol-2-amines through visible-light photoredox-catalyzed C(sp2)–H/S–H cross-dehydrogenative coupling reactions between 2-isothiocyanatonaphthalenes and amines was established.In this reaction,the new C–N and C–S bonds are formed simultaneously in a single step.This new method provides a straightforward approach for constructing valuable sulfur-containing compounds.

Oxidative dual C-H sulfenylation:A strategy for the synthesis of bis(imidazo[1,2-a]pyridin-3-yl)sulfanes under metal-free conditions using sulfur powder

An efficient approach to sulfur-bridged imidazopyridines has been developed under metal-free conditions using inexpensive sulfur powder as the sulfur source.Most appealingly,the reaction can proceed smoothly without addition of any additives,ultimately decreasing the production of chemical waste.The inexpensive and green method should provide a useful strategy for constructing a library of novel and biological interesting heteroaromatic sulfides.

Carbon–sulfur bond formation via photochemical strategies: An efficient method for the synthesis of sulfur-containing compounds

The development of green and convenient methods for C–S bond formation has received significant attention because C–S bond widely occurs in many important pharmaceutical and biological compounds.Recently, visible-light photoredox catalysis has been established as an efficient and general tool for the construction of C–C and C-heteroatom bonds. In this review, we have focused on the research on recent advances in C–S bond formation via visible-light photoredox catalysis, and the growing opportunities they present to the construction of complex chemical scaffolds for applications encompassing bioactive molecules synthesis, synthetic methodology development, and sulfur-containing drugs. We hope that this review will provide chemists with a synthetic tool that will open the door to further development of organsulfur chemistry.

Alkylsulfonium salts for the photochemical desulphurizative functionalization of heteroarenes

The development of new versatile alkylation reagents that can be transformed from diverse available chemical raw materials is highly desirable.Here,an efficient,metal-free organic photoredox-catalyzed direct alkylation of heteroarenes via a desulphurization strategy using alkylsulfonium salts as alkylation reagents under mild conditions has been described for the first time.The inexpensive and efficient organic photoredox-catalyzed method offers a new and useful strategy for constructing various biologically interesting heteroarenes in the fields of synthetic and pharmaceutical chemistry,and extends the scope of the still limited sulfonium salt photochemistry.

A desulphurization strategy for Sonogashira couplings by visible light/copper catalysis

The development of new copper-based catalysts in photoredox transformations has become a rapidly growing area of research and has been actively explored in the past several years.Herein,we have developed a new copper-based catalyst,[(binap)(tpy)Cu]Cl,and applied it in the visible-light promoted Sonogashira coupling reactions.This mild protocol results in various substituted alkynes from simple sulfonium salts which can be easily prepared from commercially available and inexpensive thiols,alcohols,and alkyl halides.This study will broaden the still limited strategies of copper photocatalysts in organic transformations.

Annulation Cascades of Cyclosulfonium Salts and Alkenes towards Sulfur-Containing N-Heterocycles by Visible Light/Copper Catalysis

Although,great achievements have been made in the synthesis of heterocycles using radical addition/cyclization strategy,developing versatile alkyl radical precursors,especially the non-stabilized long chain alkyl radicals for this strategy still remains a huge challenge.Herein,we report an efficient annulation cascade reaction between cyclosulfonium salts and alkenes for the synthesis of sulfur-containing N-heterocycles by visible light/copper catalysis under mild conditions.The C—S bond cleavage/radical cascade reaction delivers a variety of corresponding N-heterocycles containing aryl alkyl thioether motifs with good functional group tolerance.Significantly,the current system could be used for the late-stage functionalization of complex bioactive molecules.