Fundamental studies of IMA Indium-mediated allylation

1 fundamental studies of ima

1.1 organoindium intermediate
1.2 balanced equation
1.3 rate of reaction
1.4 thermodynamics

fundamental studies of ima
organoindium intermediate

although there has been confusion on precise structure of organoindium intermediates, recent publications have added considerable clarity. example, after mixing allyl bromide indium in thf, 2 compounds separately crystallized , identified monoallylindium dibromide , diallylindium bromide, illustrated below.

however, other species may present. in solution, mass spectrometry has detected variety of organoindium(iii) species such inrx, rxin, r2in, x2in, many of in equilibrium each other.

balanced equation

although attention paid organic molecules produced these reactions, overall balanced equation of ima has been determined in aqueous media. formation of organoindium intermediates illustrated in first reaction below. inclusion of, example, aldehyde electrophile represented following reaction. (the proportion of indium halide indium hydroxide depend on conditions such ph , temperature.)

rate of reaction

the rate of reaction, determined approximately tlc, appears solvent dependent. first step, formation of organoinidum intermediate @ indium surface, rapid , first order respect allyl halide. when halide bromide or iodide , convection rapid, reaction rate mass transport limited. heterogeneous rate constant first step has been determined @ least 0.01 cm/s.

thermodynamics

formation of organoindium intermediates known exothermic, no measurements of enthalpy or free energy of reactions have been reported.