Self-supported gold/chitosan nanocatalyst for chemoselective hydrogenation in π-conjugated CCCO system

A self-supported gold/chitosan nanocatalyst was easily obtained by drying a water dispersion followed by powdering it. In this system chitosan acts concomitantly as a stabilizer and support for gold nanoparticles. The self-supported gold/chitosan was applied as catalyst for CC and CO hydrogenation in conjugate and non-conjugate systems. The catalyst showed activity, driving selectivity to saturated alcohols or saturated ketones (selectivities ≥99%) depending on the reducing agent used, NaBH4 or H2 respectively. When H2 was used, the catalyst showed activity only in conjugate CCCO, forming saturated aldehydes and ketones. For isolated CC, CO or conjugate CCCC bonds, no activity was observed.