Direct thiocyanation of ketene dithioacetals under transition-metal-free conditions

Abstract

The first direct thiocyanation of ketene dithioacetals has been accomplished in the presence of N-chlorosuccinimide (NCS) and NH4SCN under transition-metal-free conditions. Terminal alkenes and hydrazine were identified to be qualified candidates for the process as well.

C4‐Selective Synthesis of Vinyl Thiocyanates and Selenocyanates Through 3,4‐Dihalo‐2(5H)‐furanones

“…However, during the access to vinyl thiocyanate derivatives, some starting materials, such as complex polysulfide‐containing olefins (Scheme a ), acetylenic ketones (Scheme b ), and olefinic compounds (Scheme c ), are not readily available, or metal catalyst is indispensable. [12c] Hence, there is an urgent need to explore a readily available, mildly conditioned synthetic process for the construction of potentially bioactive vinyl thiocyanate derivatives.…”

An Efficient Selectfluor-Mediated Oxidative Thio- and Selenocyanation of Diversely Substituted Indoles and Carbazoles

“…Owing to the aforementioned chemical versatility and biological activity, functional organic compounds bearing the thiocyanato and selenocyanate derivatives are highly sought after, and over the years a number of strategies and reagents have been utilized to enable the direct introduction of SCN and SeCN moieties into organic motifs. In particular, direct oxidative thiocyanation of C-H bonds have been achieved by using thiocyanate salts in the presence of oxidizing agents such as Mn(OAc) 3 [15], NCS [47], CAN [48], hypervalent iodine reagents [49], DDQ [50], oxone [51], oxygen [52], DEAD [53], and TBHP [22]. In comparison, direct selenocyanation approaches have not been reported under similar oxidative conditions [20][21][22][23][24][25][26].…”

Metal-Free Vinyl C–H Sulfenylation/Alkyl Thiolation of Ketene Dithioacetals for the Synthesis of Polythiolated Alkenes

“…11 Later on, the same group reported thiocyanation of the same C–H bond in ketene dithioacetals mediated by N -chlorosuccinimide. 12 Rather recently, Lei and co-workers realized the C–H alkylation of ketene dithioacetals on the α-site via the oxidation of di- tert -butyl peroxide. 13 Despite these advances, however, the overall examples on the successful α-C–H coupling of ketene dithioacetals for the construction of divergent new chemical bonds without relying on transition-metal catalysis are yet limited.…”