Synthesis of (2-alkylthiothiazolin-5-yl)methyl dodecanoates via tandem radical reaction

Abstract

A series of (2-alkylthiothiazolin-5-yl)methyl dodecanoates was synthesized from various alkyl N-allylcarbamodithioates and dilauroyl peroxide via a tandem radical hydrogen-abstraction-cyclization-substitution/combination reaction with a 5-exo-trig radical cyclization as a key step. The current route is the first, convenient, and efficient synthesis of (2-alkylthiothiazolin-5-yl)methanol derivatives.

Synthesis of functionalized 5-substituted thiazolidine-2-thiones via adscititious xanthate-promoted radical cyclization of allyl(alkyl/aryl)dithiocarbamates

“…All of the substrates 1 were easily synthesized from N-allyl secondary amines, carbon disulfide, and alkyl halides in moderate to good yields according to our previous report. 15 Compared with allyl(aryl)substrates 1a-1d which exist only as one isomer in each case, all allyl(alkyl)dithiocarbamates 1e-1q showed the presence of two different rotamers in ratios of 1 : 1 to 1.3 : 1. Various methylene substituents with strong electron-withdrawing radical stabilized groups, such as acyl, ester, cyano, and phthalimido groups, linked to the S-side participate in the reaction to give the desired cyclized products 2 in good to excellent yields (Table 2).…”

“…However, no reaction occurred when N,N-disubstituted benzyl allyl-(benzyl)dithiocarbamate was used (Scheme 1, eqn ( 2)) even with the equivalent amount of radical initiator (DLP). Accord-ing to the detailed mechanism in DLP-catalyzed radical reactions, 13 the nucleophilic undecyl radical, generated from dilauroyl peroxide (DLP), can abstract the hydrogen in N-monosubstituted dithiocarbamates 15 or attack the electrondeficient thiocarbonyl group in N,N-disubstituted dithiocarbamates to afford the tertiary carbon radical, which further undergoes a β-cleavage to form a benzyl (PhCH Á 2 ) radical. Apparently, as a moderate nucleophilic radical, 18 the benzyl radical hardly attacks the electron-rich allyl group in the dithiocarbamates, resulting in no reaction.…”

“…14 Our recent interest in radical chemistry arose from the application of dithiocarbamates in heterocyclic synthesis. We have previously described radical-induced tandem intramolecular cyclization and intermolecular radical coupling reactions in the synthesis of 2-alkylthiothiazoline derivatives from N-monosubstituted allyldithiocarbamates, 15 and dimerization in the preparation of the corresponding disulfides. 16 We also synthesized 5-substituted thiazolidin-2-ones from xanthates and tert-butyl N-allylcarbamate via an intermolecular radical addition and subsequent acid-catalyzed intramolecular cyclization.…”

Expeditious Synthesis of Dianionic-Headed 4-Sulfoalkanoic Acid Surfactants

“…They may find applications in the textile industry [ 7 ] and colloidal drug delivery system [ 10 ]. Zard’s xanthate radical addition chemistry promotes us to develop a new strategy to synthesize a series of novel dianionic-headed surfactants with a carboxylic acid and sulfonic acid functionalities in the head group region [ 11 , 12 , 13 , 14 , 15 ]. Herein, we present an expeditious synthesis of dianionic-headed surfactant 4-sulfoalkanoic acids through the radical addition of methyl 2-((ethoxycarbonothioyl)thio)acetate to linear terminal olefins and subsequent oxidation with peroxyformic acid ( Scheme 1 ).…”

Amide exchange reaction: a simple and efficient CuO catalyst for diacetamide synthesis

“…Given the potential applications of HMBA, considerable work has gone into its production. [26][27][28] The traditional preparation method of HMBA, however, still utilises a noble metal complex catalyst and an organic solvent under an inert atmosphere and has a low yield. As shown in Scheme 1, RuH 2 (PPh 3 ) 4 was employed in the reaction of HDA, CH 3 CN, and H 2 O to prepare HMBA using dimethoxyethane (DME) as the solvent under an argon atmosphere, in only 89% yield.…”