An immobilized organotin catalyst for reduction of ketones and aldehydes

Methodologies Limiting or Avoiding Contamination by Organotin Residues in Organic Synthesis

“…Meanwhile, Matlin et al described the use of organotin dialkoxides grafted on a silicate type support (Corasil II silica) as catalysts for the polymethylhydrosiloxane (PMHS) reduction of ketones and aldehydes (Scheme 56). 283 The authors report that a batch of catalyst was recycled throughout four successive reduction sequences without noticeable activity lowering.…”

Polymethylhydrosiloxane

“…12 Similar reductions can be made catalytic in tin by using dibutyltin dilaurate, 13 bis(dibutylacetoxytin) oxide (DBATO), 14 or polymer-supported organotins. 6 In some cases, these catalytic protocols have proven more successful than their stoichiometric counterparts (eq 3). However, enones suffer from competitive 1,4-reductions.…”

Organometallic Polymers of Germanium, Tin and Lead

“…A promising approach to preparing insoluble organotin reagents which can easily be recovered by filtration is the anchoring of functionalised organotin compounds to inorganic matrices. The immobilised organotin reagents 68 and 69 were prepared starting from aluminium oxide and silica gel 155,156 .…”

“…After recovering and reconverting the polymer-supported organotin halide into the corresponding organotin hydride 68 by reaction with diisobutyl aluminium hydride, the activity is almost halved with respect to the starting material. The silicalinked polymer 69 efficiently functions as an in situ prepared hydride transfer reagent for the reduction of carbonyl compounds using polymethylhydrosiloxane (PMHS) as hydrogen source 156 . After use and recovery of the polymer-supported organotin compound, no significant loss of activity was observed.…”