Synthesis of α-Trifluoromethylthio-α,β-Unsaturated Carbonyl Compounds by DABCO-Mediated Electrophilic Trifluoromethylthiolation with N-SCF₃-Dibenzenesulfonimide

Abstract

A DABCO-mediated electrophilic α-trifluoromethylthiolation of α,β-unsaturated carbonyl compounds comprising no β-substituents has been achieved using N-trifluoromethylthio-dibenzenesulfonimide as the SCF 3 source. The direct trifluoromethylthiolation provides the corresponding α-trifluoromethylthio-α,β-unsaturated carbonyl products in good yields (up to 88%). Furthermore, the vinyl group in the α-trifluoromethylthioα,β-unsaturated carbonyl product was successfully transformed into diverse functional groups in good to excellent yields (70−95%) by reactions such as epoxidation, aziridination, hydrocyanation, and hydrogenation.

Direct Synthesis of Disubstituted Trifluoromethylthiolated Alkenes

“…34 Cho and co-workers described the synthesis of these 1,1-trifluoromethylthiolated difunctionalized alkenes by means of a DABCO-mediated electrophilic trifluoromethylthiolation reaction using the reagent XI (Scheme 14). 35 With this methodology, the trifluoromethylthiolation of ,-unsaturated ketones (19 examples, up to 88% yield) and ,-unsaturated esters (6 examples, up to 87% yield) was achieved smoothly. In the first case, the reaction was tolerant to (hetero)aromatic and aliphatic ,-unsaturated ketones (29a, 29b and 29c, respectively), and also regioselective in the case of ketone 29d, in which the cyclohexene moiety remained intact.…”

“…Scheme 14 Synthesis of trifluoromethylthiolated 1,1-disubstituted alkenes starting from ,-unsaturated ketones and esters35 …”

Research Progress in C—S Bond Formation Reaction of Olefins with Organic Sulfur Reagents under Photocatalyst-Free and Non-Electrochemical Conditions

“…当然, 以(PhSO 2 ) 2 NSCF 3 为 SCF 3 的来源, 也能在普 通烯烃的 β-位成功引入三氟甲硫基 [146] . Cho 课题组 [147] 以丙烯酮为底物, 在 C＝C 键的 α-位引入了三氟甲硫基. 除(PhSO 2 ) 2 NSCF 3 外, N-三氟甲硫基丁二酰亚胺 [148] 与 N-三氟甲硫基邻苯二甲酰亚胺 [149] 也是表现优异的三 氟甲硫基化试剂, 均可应用于烯烃底物 [150][151] .…”

Mild Darzens Annulations for the Assembly of Trifluoromethylthiolated (SCF3) Aziridine and Cyclopropane Structures

“…Only a single example to access a disubstituted SCF 3 -containing aziridine has been reported (Figure 1a), which involved direct aziridination of a vinyl ketone containing an α-SCF 3 group. 17 No trisubstituted routes have been reported to date. With regards to SCF 3cyclopropanes, Haas and Hinsken introduced the first route in 1985 (Figure 1b).…”

“…There are very few reported methods to access SCF 3 -containing aziridines and cyclopropanes. Only a single example to access a disubstituted SCF 3 -containing aziridine has been reported (Figure a), which involved direct aziridination of a vinyl ketone containing an α-SCF 3 group . No trisubstituted routes have been reported to date.…”