Epoxides indium triflate

Indium trichloride induces rearrangement of aryl-substituted epoxides to the respective aryl-substituted acetaldehydes via an exclusive hydride shift As phenyl group migration occurs more readily than hydride migration, stilbene oxide is converted to diphenylacetaldehyde (Scheme 8.140) [184]. N-Tosyl aziridines react smoothly with carboxylic acids in the presence of a catalytic amount of indium triflate to afford the corresponding -aminoacetates and benzoates (Scheme 8.141) [185]. Indium trichloride and indium bromide catalyze regio- and diastereoselective azidolysis, bromolysis, and iodolysis of a, -epoxycarboxylates in water (Scheme 8.142) [186]. 

Gao, B. Wen, Y. Yang, Z. Huang, X. Liu, X. Feng X. (2008) Asymmetric ring opening of meso-Epoxides with aromatic amines catalyzed by a new proline-based N,N -dioxide-indium tris (triflate) complex,/t/v. Synth. Catal, 350 385- 390. 

Certain Lewis acids are known to induce an epoxide-aldehyde rearrangement <01TL8129>, and this chemistry has recently been combined in tandem with metal-mediated allylations. For example, epoxides react with tetraallyltin in the presence of bismuth(III) triflate to give homoallylic alcohols 116. The reaction involves an initial 1,2-shift to form an aldehyde 115, which is then attacked by the allyl tin species <03TL6501>. A similar but operationally more straightforward protocol is available by combining allyl bromide with indium metal, followed by the addition of epoxide <03TL2911>. 

A series of peracetylated Cl-deoxyalditol and C-glycoside dipyrranes were prepared from the corresponding dithioacetal derivatives yields of the pyrrole condensation were reported to be up to 62% (13TL1137). En route to a synthesis of the marineosins, Lindsley utilized a late-stage incorporation of the pyrrole moiety by the nucleophilic displacement of an iminium triflate salt (13TL2231) a related approach was disclosed by Shi et al. (130BC2936). Konduru and Ahmed used pyrrole and indole to open chal-cone epoxides with catalytic amoimts of indium (111) chloride (13SC2008). 

Epoxides react smoothly with thiols in the presence of 10 mol% of indium(III) triflate to afford the corresponding -hydroxy sulfides in high yields with high regioselectivity. ... 

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