indium hydride is a low-valent metal compound that is widely used as a reducing agent and in some cases as an inert gas. It is a soft, ductile, man-leable, lustrous metallic silvery white element with a face-centered tetragonal structure.
It has a high oxidation number of 1 and it is stable at standard temperature and pressure. It can wet glass and it ignites with a violet flame.
Lithium indium hydride, a Lewis acid, is an efficient in-situ reducing agent for reactions such as Friedel-Crafts acylations and Diels-Alder condensations between barbituric acid and aldehydes. It can also be used in Knoevenagel condensations between aryl and alkyl halides or as an in situ reducing agent for the preparation of nitromethane from nitrogen and hydrogen.
Indium tri(isopropoxide) is a versatile reagent for chemoselective reduction of alcohols to the corresponding alkanes. This indium hydride is particularly useful for benzylic and secondary alcohols with good to excellent chemoselectivity, as well as the synthesis of primary alkanes from aromatic and heteroaromatic aldehydes and amides.
Reduction of simple and functionalized iodoalkanes with PhSiH3 in THF at 70 C afforded dehalogenated alkanes in good to excellent yields. The reaction is applicable to the one-pot synthesis of alkyl cyanides from carboxylic acids via reductive iodination or bromination.
indium hydride was first generated by the transmetalation of indium trichloride with tributylstannane at -78 degC, and it has been found to be very stable at room temperature. It is used for mild and selective cleavage of tert-butyldimethylsilyl ethers, as well as for many other organic transformations.