Free Radical Promoted Trifluoromethylthiolation of Alkynes to Access SCF₃-Containing Dibenzazepines or Dioxodibenzothiazepines

Abstract

Persulfate-promoted radical cascade trifluoromethylthiolation of aryl acetylenes with AgSCF3 provides a simple reaction system for the synthesis of SCF3-substituted dibenzazepines or dioxodibenzothiazepines with good Z/E selectivity. The single-crystal X-ray diffraction data confirms the structures of the final products. A series of scaled-up experiments, further transformations, and radical inhibition experiments were operated in the reaction system.

Microwave‐Assisted Synthesis of Fluorinated 5‐Membered Nitrogen Heterocycles

“…Medicinally important, fluorinated trispiropyrrolidine/ thiapyrrolizidine derivatives were synthesized in a two-step synthetic process employing 2,2,2-trifluoroethanol (TFE) as a reusable solvent. [62] In the first step, 7,9-bis[(E)arylidene]-1,4-dioxaspiro [4,5]decane-8-ones ( 16) was synthesized by treatment of spiro [4,5]decan-8-one (15) with 4-fluorobenzaldehyde and potassium carbonate (K 2 CO 3 ) in water under MW heating in excellent yield in short reaction time as compared to conventional heating (Scheme 7). [63] The compound 16 obtained in this step was further reacted with isatin and sarcosine or thiaproline in TFE to get the fluorinated trispiropyrrolidine (17) or pyrrolothiazole (18) derivatives respectively (Scheme 7).…”

“…Nitrogen (N)-containing heterocyclic compounds are more common in nature than the other heterocyclic ring systems. [1][2][3][4] Fluorinated N-heterocycles, a subclass of N-heterocycles, historically traced back to the synthesis of 2-fluoropyridine by Chichibabine in 1915, however extensive research towards their synthesis did not begin until World War II. [5,6] The CÀ F bond is one of the strongest (115.7 kcal/mol) and most polar (dipole moment 1.41 D) bond.…”

Metallaphotoredox catalysis enables facile (trifluoromethyl)thiolation of alkenyl iodides

“…2A, X = COOH, NO 2 and H) including the conversion of cinnamic acids, 26,27 β-nitrostyrenes, 28 terminal alkenes, 29,30 methylenecyclopropanes, 31 and epoxides 32 to their alkenyl-SCF 3 counterparts. Moreover, the conversion of alkynes has been prominent, prototypically proceeding under Cu or silver (Ag) mediated conditions and employing an external oxidant; 12,[33][34][35][36][37][38] however, catalyst-free 39 and photoredox mediated 40 variants have been reported.…”

Photo-induced spirocyclization of biaryl ynones with ammonium thiocyanate: access to thiocyanate-featured spiro[5,5]trienones

“…The above problems are being studied by our group. Based on our previous radical study, 19 we finally developed a mild, solely 6- exo-trig spirocyclization of biaryl ynones with NH 4 SCN, which resulted in SCN-modified spiro[5,5]trienones with good regioselectivity and a broad substrate scope. Meanwhile, other SCN-substituted cycles also could be obtained under similar radical conditions.…”