Perfluoro Allyl Fluorosulfate (FAFS): A Versatile Building Block for New Fluoroallylic Compounds

Abstract

In this study we will present and discuss both the synthesis of CF2=CFCF2OSO2F (perfluoroallyl fluorosulfate, FAFS), focusing in particular on the important role of C3F6/SO3 ratio, reaction temperature and boron catalyst/SO3 ratio on FAFS’ yield and selectivity, as well as a wide variety of ionic and radical reactions possible with FAFS. We focused our attention on reactions of FAFS with aliphatic and aromatic alcohols, acyl halides, halides, H2O2, ketones and radicals whose synthesis and reaction mechanisms will be presented and discussed. Particular attention will be devoted to the novel diallyl-fluoroalkyl peroxide obtained. Factors such as pKa and Lowry and Pearson’s Hard/Soft Acid-Base Theory which determine the selectivity between Addition/Elimination vs. Nucleophilic Substitution reaction mechanisms on FAFS will also be presented and discussed.

Synthesis of 2-Fluorobenzofuran by Photocatalytic Defluorinative Coupling and 5-endo-trig Cyclization

“…Although α-CF 3 -styrenes with various substituents on the aromatic ring have been successfully employed in the photocatalytic defluorinative cross-coupling reactions, α-CF 3 - ortho -hydroxystyrenes have remained elusive substrates in all the reports . The challenge is threefold: (1) the o -OH group decreases the electron-deficient nature of α-CF 3 -styrenes, lowering the activity of the C–C double bond toward nucleophilic radical species; (2) the low oxidation potentials of phenols, especially their phenolate forms under basic conditions, render them competitively reductive quenchers of excited photocatalyst; (3) phenol has considerable reactivity toward α-CF 3 -alkenes via either ipso -defluorooxylation or S N 2′-type substitution under basic conditions . Herein, we present our efforts on the application of α-CF 3 - ortho -hydroxystyrenes in a photocatalytic defluorinative cross-coupling reaction.…”

Development and Application of O-(Trimethylsilyl)aryl Fluorosulfates for the Synthesis of Arynes

“…Since fluorine is the most electronegative element in the periodic table, the cleavage of the sulfonyl-fluorine bond is extremely difficult, making it hard for −SO 2 F to act as halogenating agents. Considering the unique property of the sulfonyl fluoride group, we envisioned that the simple -OSO 2 F could be used as an inexpensive -OTf alternative and serves as a leaving group for the developing of a new type of aryne precursors 2 . − As shown in Figure (eq 2), 2a was prepared in high yield by simply exposing the corresponding o -TMS phenol to sulfuryl fluoride in the presence of triethylamine . Sulfuryl fluoride is a broad spectrum biocide, and its global production is about 3 million kilograms per year, , making it a very cheap starting material.…”

Fluorinated Analogs of Organosulfur Compounds from Garlic (Allium sativum): Synthesis, Chemistry and Anti-Angiogenesis and Antithrombotic Studies

“…Three types of C–F substituted allyl groups were considered for this study, namely CH 2 =CFCH 2 –X ( A ), CF 2 =CFCH 2 –X ( B ), and CF 2 =CFCF 2 –X ( C ). We chose type A based on commercial availability of CH 2 =CFCH 2 Cl (3-chloro-2-fluoroprop-1-ene ( 9 ) ( Scheme 2 ), as well as on our inability to convert thioacetate CF 2 =CFCH 2 SAc (from Mitsunobu reaction of CF 2 =CFCH 2 OH [ 16 ]) to the corresponding disulfide, and on the relative inaccessibility of precursors C , such as CF 2 =CFCF 2 OSO 2 F [ 17 ]. Here, we describe our efforts to synthesize and study the reactivity and activity of difluoroallicin 12 ( S -(2-fluoroallyl) 2-fluoroprop-2-ene-1-sulfinothioate), easily prepared from 9 , and related compounds such as S -2-fluoro-2-propenyl- l -cysteine (fluorodeoxyalliin, 13 ), 1,2-bis(2-fluoroallyl)disulfane ( 11 ), 5-fluoro-3-(1-fluorovinyl)-3,4-dihydro-1,2-dithiin ( 16 ), trifluoroajoene (( E , Z )-1-(2-fluoro-3-((2-fluoroallyl)sulfinyl)prop-1-en-1-yl)-2-(2-fluoroallyl)disulfane, 18 ), and 1,2-bis(2-fluoroallyl)polysulfane ( 21 ).…”