The current method represents an electrochemically driven synthetic route to access polysubstituted selenofuran derivatives through the diselenide-promoted cyclization of homopropargyl alcohols. The tandem electro-oxidative transformation operates at ambient temperature and in the absence of an external oxidant. This mild and efficient methodology exhibits good functional group compatibility, providing a broad range of substrate scopes up to 84% isolated yield. Further conversion of the seleno-functionality afforded other valuable furan derivatives.

Electrochemical organic transformations have made enormous progress over the past decades owing to the idiosyncratic redox nature. Electrochemistry is globally acknowledged for its sustainability and environ friendliness and several well-known redox processes get a new exquisite touch without expelling chemical waste and toxic by-products. Apart from this, electrochemistry has adequate potential to steer numerous non-spontaneous reactions like cross-coupling, C−C bond cleavage, radical generation, directed C–H functionalization reactions etc. in a straightforward manner. Beyond the electrochemical oxidation reactions, electrochemical reductive transformations are also enriching in the last few years. Electrochemical reduction can be facilitated by using different strategies like using a sacrificial electrode, sacrificial reagent or can be accomplished in a divided cell. In this short review, different methods for the functionalization of C−halogen bonds, including detailed mechanistic approaches, are discussed. 1 Introduction 2 Different strategies for the electrochemical reduction 3 Functionalization of C−halogen bonds through electrochemical reduction 3.1 Electro-reductive hydrodehalogenation 3.2 Electro-reductive C−C coupling of organohalides 3.2.1 Aryl-aryl C−C coupling 3.2.2 Aryl-alkenyl C−C coupling 3.2.3 Aryl-alkyl C−C coupling 3.2.4 Alkyl-alkenyl C−C coupling 3.2.5 Alkyl-alkyl C−C coupling 3.3 Electro-reductive coupling of organohalides with carbonyls (C=O) 3.4 Electro-reductive coupling of organohalides with organoborones 4 Conclusion

The current methodology reveals a green and proficient electro-oxidative tandem selenocyclization of thioallyl benzoimidazoles manufacturing selenylated dihydro-benzoimidazo-thiazine derivatives. Both CÀ Se and CÀ N bond formation were achieved via this mild protocol which exhibits good functional group tolerability affording an extensive range of substrate scope up to 96% isolated yields. Complete control over the regioselective formation of the six-membered heterocycle and stereoselective construction of the contiguous stereocenters was established. The practical electrochemical method operates in an undivided cell at ambient temperature without using any metal and external chemical oxidant.

The developed methodology describes an environmentally benign protocol for electro-oxidative CF3-radical generation, followed by cascade cyclization fabricating isoxazoline scaffold from β,γ-unsaturated oxime. Consecutive C−O and C−C bond formations were achieved...

The current protocol represents a transition metal-free synthesis of polysubstituted phenanthridines from abundant starting materials like benzhydrol and 2-iodoaniline derivatives. The reaction involves sequential oxidation of alcohol and direct condensation reaction with the amine resulting in a CÀ N bond formation followed by a radical CÀ C coupling in a cascade sequence. The used base potassium tert-butoxide plays a dual role in dehydrogenation and homolytic aromatic substitution reaction. Using this methodology, twenty substituted phenanthridine derivatives were synthesized with up to 85% isolated yield.