Direct electrochemical detosylation of tetratosylcyclen to cyclen with carbon cathodes

Synthetic Organic Electrochemical Methods Since 2000: On the Verge of a Renaissance

“…Silvestri reported the detosylation of tetratosylcyclen using carbon cathodes under direct electrolysis. 856 Grognec, Quintard, and co-workers described electrochemical conditions for the deprotection of N -phenylsulfonyl N -substituted amines. 857 However, when this protocol was extended to cyclopropylamine derivatives, ring fragmentation products were observed.…”

“…This mediatory system obviated the need for a mercury cathode while tolerating sensitive functionalities such as aziridine. Silvestri reported the detosylation of tetratosylcyclen using carbon cathodes under direct electrolysis . Grognec, Quintard, and co-workers described electrochemical conditions for the deprotection of N -phenylsulfonyl N -substituted amines .…”

Electrically Driven N(sp2)–C(sp2/3) Bond Cleavage of Sulfonamides

“…A survey of the known electrochemical behaviors of sulfonamides is shown in Scheme . Under reductive electrochemical conditions, the selective cleavage of the N–S bond is well documented as a mild tosyl deprotection strategy. − By contrast, under oxidizing electrochemical conditions, there are limited examples of Shono-type dehydrogenative couplings in sulfonamides compared to the well-studied tertiary amides. − To the best of our knowledge, a C–N bond cleavage reaction of a sulfonamide can only be achieved using conventional stoichiometric chemical routes. − Other electrochemical properties of sulfonamides include its use as a directing and participating group for 1,5- and 1,6-cyclizations and its use as a competent nucleophile in anodic oxidations . Although the chemical removal of protecting groups attached to sulfonamides is known to reveal an N –H functional handle (e.g., SEM, Bn, PMB, allyl, t Bu ), to the best of our knowledge, the late-stage electrochemical oxidative cleavage of operationally inert N (sp 2 )– C (sp 2/3 ) bonds (e.g., alkyl, aryl substituents) adjacent to a sulfonamide is unknown in this important class of compounds using a green methodology.…”

Electrochemical synthesis of coenzymes Q n by oxidation of tetramethoxy precursors

“…Although the electrochemical reaction usually is only one step in a complex sequence, it has often the key-role of generating the activated intermediate. Hence, in the last years industrial and academic groups were involved several times in the investigation of new electrosynthetic routes for the preparation of fine and specialty chemicals [1][2][3][4]. Interestingly, many of these researches are not known because of secrecy requirements [1].…”