The use of free radical initiators bearing metal–metal, metal–hydrogen and non-metal–hydrogen bonds in synthesis

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.…”

“…Mn-alkyls photolyze very easily, and are not considered effective in radical reactions (76). Thus, CRPs based on reversible termination with Mn(CO) 5 • are not likely to be effective.…”

“…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).…”

New and efficient synthesis of solid-supported organotin reagents and their use in organic synthesis

“…Stannyl radicals have played a central role in the development of this chemistry, and tributyltin hydride has been one of the most popular reagents for propagating radical reactions. Distannane reagents have also been a popular source of stannyl radicals since homolytic cleavage of tin-tin bonds takes place under mild conditions [17]. Distannane reagents have been widely used, in particular, for atom transfer cyclisations [18] where premature termination of the radical chain by a hydrogen atom donor is to be avoided.…”

Control of Asymmetry in the Radical Addition Approach to Chiral Amine Synthesis

“…[37] We noted, however, that manganese carbonyl [38] [Mn 2 (CO) 10 ] ( λ max 340 nm, σ Mn–Mn → σ* Mn–Mn ) may be photolyzed without any sensitizer, leading to homolytic metal–metal bond cleavage. This produces two •Mn(CO) 5 radicals, which are well-known to abstract halogen atoms from alkyl halides.…”