Tin- and indium-mediated allylation in aqueous media: application to unprotected carbohydrates

Electrochemical Regeneration of Low-Valent Indium(I) Species as Catalysts for C−C Bond Formations

“…[3] In contrast, when the crotylation of benzaldehyde is performed starting from indium metal the g-substitution product is formed exclusively under otherwise identical reaction conditions. [11] In our electrochemical crotylation of benzaldehyde we found the product distribution is almost identical with that obtained in the indium(i)-mediated crotylation (Scheme 5 metalation of the allyl group from indium to aluminum can also be excluded since both the stoichiometric crotylation using preformed allylaluminum sesquihalides, as well as the relatively slow electrochemical reaction in the absence of indium(iii) salts, also furnishes the g-substitution product exclusively. Further support for the involvement of indium species and not aluminum-derived C À C bond formation is provided by the electrochemical reaction of propargyl bromide with benzaldehyde, which gives, under electrochemical conditions, a mixture of the corresponding homopropargylic alcohol and the allenylic alcohol in a ratio of 3:1 (Scheme 6), while an electrolysis in the absence of indium gave no desired product.…”

Occurrence, Synthesis and Biosynthesis of Bacterial Heptoses

“…Again, the osmylation followed Kishi's empirical rule giving rise to the product with erythro-configuration between O-3 and O-4 which was isolated as peracetate 50. In this way, D-glycero-D-galactoheptose 4 was prepared in a fair overall yield [105][106][107].…”

Indium‐Mediated Allenylation of Aldehydes and Its Application in Carbohydrate Chemistry: Efficient Synthesis of D‐Ribulose and 1‐Deoxy‐D‐ribulose

“…[30,31] In a three-step synthesis, 29 was obtained in an overall yield of 51 % starting from 1 and by using 1-bromo-2-butyne as an acetyl anion equivalent. [32] In comparison to the literature, [33] when adding LiI the applied quantities of 1-bromo-2-butyne and indium were decreased by a factor of two and four, respectively. Because 3a is a fully orthogonally protected precursor, the sequence of deprotection steps can be easily altered, giving rise to various derivatives of pentulose (24, 26, and 28).…”