Electrolytic Partial Fluorination of Organic Compounds. 24.¹ Highly Regioselective Anodic Monofluorination of 2-Benzothiazolyl and 5-Chloro-2-benzothiazolyl Sulfides

Abstract

Electrochemical fluorination of 2-benzothiazolyl and 5-chloro-2-benzothiazolyl sulfides was successfully carried out using Et 4 NF‚3HF as a supporting electrolyte and fluoride ion source in dimethoxyethane to provide the corresponding R-monofluorinated sulfides in good yields. Fluorination took place selectively at the position R to the sulfur atom of the sulfides, and the heterocyclic moieties were not fluorinated at all.

Sulfanyl- and Selanyldifluoromethylphosphonates as a Source of Phosphonodifluoromethyl Radicals and Their Addition onto Alkenes

“…To the best of our knowledge, only the synthesis of alkylsulfanyldifluoromethylphosphonates has been reported using electrochemical fluorination of sulfides (millimole scale). Under these conditions 4 equiv of 4HF·FNEt 4 was used as fluorine source to produce difluorophosphonates in about 50% yields …”

Fluoro-Julia Olefination as a Mild, High-Yielding Route to α-Fluoro Acrylonitriles

“…We first focussed on the synthesis of (1,3-benzothiazol-2-ylsulfonyl)fluoroacetonitrile. Reaction of bromoacetonitrile ( 1 ) with the sodium salt of 2-mercapto-1,3-benzothiazole resulted in 2a 16 in 88% yield, that was subjected to oxidation to 1,3-benzothiazol-2-ylsulfonyl (BT-sulfonyl) derivative 3 (Scheme 1). The use of m -CPBA gave a low yield of 3 , whereas dimethyldioxirane or oxone led mainly to the sulfoxide derivative.…”

Synthesis of Fluoroolefins via Julia-Kocienski Olefination

“…A series of variously functionalized heteroaryl methyl sulfides was subjected to anodic fluorination using Et 4 NF•3HF or Et 4 NF•4HF as a supporting electrolyte and fluoride source, to yield benzothiazolyl, 55,56 5-chlorobenzothiazol-2-yl (5-Cl-BT), 55,56 phenyltetrazolyl, 57 2-pyridyl, 56,[58][59][60] and 2-pyrimidyl 56,58,60 fluoromethyl sulfide derivatives (Scheme 36). Mixed fluoroolefination reagents containing a phosphonate and either a pyridyl or pyrimidyl sulfone moiety have also been synthesized (Scheme 38).…”