Radicals in organic synthesis. Part 1

Inhibitors of HCV NS5A: From Iminothiazolidinones to Symmetrical Stilbenes

“…18,19 A radical mechanism is consistent with the formation of 47 by a process involving combination of a C-5 radical with oxygen that would give hydroperoxide A (Scheme 2). Precedent for peroxide formation and reductive cleavage in/by 20,21 Unique to B, however, is the potential for ring-opening to the R-ketoamide C, which can reclose in a complementary fashion to form the 2-thiohydantoin 47, with experimental support for this sequence of events obtained as follows. Snider has reported that radicals generated in the presence of Mn(OAc) 3 /Cu(OAc) 2 can undergo further oxidation in which the resulting cation is trapped by acetic acid.…”

Photochemically Enabled Iodine Degenerative Transfer Controlled Radical Homo- and Block Copolymerization of Vinylidene Fluoride at Ambient Temperatures with Mn2(CO)10and Visible Light

“…After reversible photodissociation of Mn 2 (CO) 10 (eq. 1), subsequent irreversible (102, 103) halide abstraction from R-X (and later from PVDF-X), which is driven by the formation of high BDE Mn-X (75,76,139), X = Cl, Br, I, (eq. 2) affords Mn(CO) 5 -X and R • , which, if reactive enough, adds to VDF, typically at the CH 2 side, driven by polar effects, initiating polymerization (eq.…”

“…In addition, while we have shown that Cp 2 TiCl is an excellent mediator for the CRP of styrene (59)(60)(61)(62)(63)(64)(65)(66)(67)(68)(69)(70)(71) and dienes (72), as well as for the living ring opening polymerization of cyclic esters (73,74), a solvent compatible with both Cp 2 TiCl and PVDF was not found. Thus, as none of the conventional CRP protocols or R-CF 2 -I activators tested worked, we decided to investigate alternative, photochemical means of radical generation and trapping (75,76).…”

Flow Giese reaction using cyanoborohydride as a radical mediator

“…Organo halides are among the most useful precursors to access carbon radical species, and they have found numerous applications in chemical synthesis [1–5]. Alkyl radicals are classified as nucleophilic radicals, and therefore they are able to add preferentially to alkenes possessing an electron-withdrawing substituent [6–7].…”