Tris-iodonium salt

Likewise, the reaction [42] of three equivalents of 7 with the tris-tin-alkyne 37 in cold dichloromethane gives the symmetrical tris-iodonium salt 38 [Eq. (19)]. 

The initiating radicals are assumed to be SCN, ONO or N3 free radicals. Tris oxalate-ferrate-amine anion salt complexes have been studied as photoinitiators (A = 436 nm) of acrylamide polymer [48]. In this initiating system it is proposed that the CO2 radical anion found in the primary photolytic process reacts with iodonium salt (usually diphenyl iodonium chloride salt) by an electron transfer mechanism to give photoactive initiating phenyl radicals by the following reaction machanism ... 

Finally, vinyl(tri-rc-butyl)stannanes have also been utilized with iodosylbenzene and Meerwein s reagent126 for the synthesis of the ( rr-butylcyclohexenyl)iodonium tetrafluoroborate shown in equation 162 and with iodosylbenzene/BF3-etherate to give the (ketovinyl)iodonium salt shown in equation 169128. 

This procedure has been used for the preparation of the bis-iodonium acetylenes 356 and 357 [460,488], conjugated 358 and unconjugated 359 bis(alkynyliodonium) salts [489-491], tris(alkynyliodonium) salts 360 [491] and diynyl(phenyl)iodonium triflates 361 [492] (Scheme 2.101). 

Examples of additives are the following EA = iodonium salt, e.g. diphenyliodonium hexafluorophosphate (more rarely, a sulfonium salt) and related derivatives [113], alkyl halide, e.g. phenacyl bromide [1.14] and triazine, e.g. 2,4,6-tris(trichloromethyl)-l,3,5-triazine ED = borate disulfide, group IVb dimetal [1.15] HD = alcohol, THE, thiol, benzoxazine, aldehyde, acetal, silane (e.g. tris(trime1hylsilyl)silane = (TMS)3Si-H) [1.16]), germane, borane, stannane, alkoxyamine, silyloxyamine, polymer substrate, etc. EPD = amine [1.17], thiol, etc. The generated radicals (e.g. Ph, R, RsSi, RR C R R in [1.13]-[1.17] ) are the initiating species. Efficient novel or newly modified dye structures in the Dye/amine, Dye/iodonium salt or Dye/silane two-component PISs have been proposed within the last 4 years (see section 1.3.5). 

Palladium(II)-copper(I) cocatalyzed couplings of several (/ ,/ -dialkylvinyl)phenyliodo-nium triflates with 4-isopropoxy-3-tri- -butylstannyl-3-cyclobutene-l,2-dione (71) in DMF at room temperature have recently been described (equation 259)157. As observed in earlier studies of Cu(I)- or Pd(II)-promoted reactions of vinyliodonium salts, the vinyl ligands are introduced with retention of configuration. Since iodobenzene is a byproduct of ligand coupling, the production of 3-phenyl-4-isopropoxy-3-cyclobutene-1,2-dione might also be expected. However, the (/ ,/ -dialkylvinyl)iodonium ions are much more reactive... 

Interest in the synthesis and reactivity of the six-membered, potentially aromatic, phosphinine ring system has also continued, but at a much lower level than in recent years. New synthetic work includes the application of the pyrylium salt route to phosphinine synthesis, this time starting from pyrylium salts bearing chiral substituents to give the related chiral phosphinines," and the development of new routes to the 2-phosphanaphthalene (137)" ° and the phosphinine-2-aldehyde (138). Also reported is an approach to the synthesis of l,2-dihydro-l,4,2-benzo-diazaphosphinines," cationic gold(I) complexes of 2,4,6-tri-t-butyl-l,3,5-triphosphabenzene," and the synthesis of some X -phosphinines from phosphonium-iodonium ylides." " ... 

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