An electrochemical multicomponent reaction toward C–H tetrazolation of alkyl arenes and vicinal azidotetrazolation of alkenes

Abstract

The widespread use of tetrazoles in medicine, biology, and materials sciences continuously promotes the development of their efficient and selective syntheses. Despite the prosperous development of multicomponent reactions, the use...

Recent Advances in Multicomponent Electro‐Organic (Electrochemical) Synthesis of Heterocycles

“…The reaction is characterized by a wide range of substrates, metal-free and chemical oxidants, scalability, and the mild conditions of operation. [54] It has been reported that Mohammedi et al prepared novel tetrahydroimidazo[1,2-a]pyridine-5(1H)-1 derivative (56) using electro-synthesis in one pot by combining aldehydes (1'), Meldrum's acid ( 55), and 2-(nitro-methylene)imidazolidine (49) in good to excellent yields of 70-96% (Scheme 25). As part of the process, ethanol was applied to a propanol medium with sodium bromide present as an electrolyte inside an undivided cell under a constant current of 50 milliamps.…”

“…Several substituted styrenes (39) displayed good tolerance, resulting in excellent to moderate yields of vicinal azidotetrazoles (38). [49]…”

“…The scope of the electrochemical vicinal azidotetrazolation was then investigated. Several substituted styrenes ( 39 ) displayed good tolerance, resulting in excellent to moderate yields of vicinal azidotetrazoles ( 38 ) [49] …”

Electrochemical Difunctionalization of Alkenes

“…Very recently, Ye and coworkers pioneered a multicomponent electrochemical azidotetrazolation of alkenes with acetonitrile and azido trimethylsilane for the synthesis of vicinal azidotetrazoles (Scheme 15). 14 In the scheme, the excess azidotrimethylsilane is not only the source of the initial azido radical, it is also the key to the reaction with the Ritter-type nitrile ion intermediate to generate the vicinal azidotetrazole products. Unfortunately, this protocol is not applicable to benzonitrile due to its weak nucleophilic properties.…”

Electrochemical multicomponent reaction toward vicinal sulfenyltetrazolation of unactivated alkenes

“…8 Recently, we have developed an electrochemical multicomponent reaction (e-MCR) for the vicinal azidotetrazolation of alkenes and C–H tetrazolation of alkyl arenes using acetonitrile other than the commonly used isocyanides (Scheme 1B). 9 The key feature of this e-MCR is the electrochemical generation of a Ritter-type intermediate 10 that bypasses the low reactivity of acetonitrile in 1,3-dipole cycloaddition. To further investigate this e-MCR strategy in the preparation of structurally diverse tetrazoles, we herein report our research progress on the vicinal sulfenyltetrazolation of unactivated alkenes with the readily available thiols, azidotrimethylsilane (TMSN 3 ) and acetonitrile (Scheme 1C).…”