A Useful, Reliable and Safer Protocol for Hydrogenation and the Hydrogenolysis ofO‐Benzyl Groups: The In Situ Preparation of an Active Pd⁰/C Catalyst with Well‐Defined Properties

Abstract

A simple, highly reproducible protocol for the hydrogenation of alkenes and alkynes and for the hydrogenolysis of O-benzyl ethers has been developed. The method features the in situ preparation of an active Pd(0)/C catalyst from Pd(OAc)(2) and charcoal, in methanol. The mild reaction conditions (25°C) and low catalyst loading required (0.025 mol%), as well as the absence of contamination of the product by palladium residues (<4 ppb), make this a sustainable, useful process for organic chemists. Alternatively, the protocol can be carried out under microwave activation, to shorten the reaction times, with cyclohexene as the hydrogen source.

In vitro and in vivo evidence for the inhibition of brassinosteroid synthesis by propiconazole through interference with side chain hydroxylation

“…(Toyama, Japan), Campestanol was prepared by reduction of campesterol based on a method as described previously. 36 All of the chemicals for biological studies, unless otherwise described, were dissolved in DMSO and stored at ¡30 C before use.…”

Stereoselective Hydrosilylation of Enals and Enones Catalysed by Palladium Nanoparticles

“…For example, they are active catalysts for hydrogenolysis and hydrogenation reactions. [19] To confirm that the hydrosilylation activity is not restricted to catalysts prepared with silane reduction, we also prepared poly(N-vinyl-2-pyrrolidone) (PVP)-stabilised PdNPs. [20] These PVP-stabilised PdNPs are also active catalysts for hydrosilylation, affording the same stereoselectivity for 2 a (>25:1 Z/E ratio) as our own in situ prepared PdNP catalyst, but with a lower chemoselectivity and reaction rate.…”

Catalysts based on large size-controlled Pd nanoparticles for aqueous-phase hydrodechlorination

“…The most relevant are those related to the active phase, i.e. nanoparticles (NPs) size [5][6][7][8] and shape [9][10][11][12], and to the support, mainly pore size [13][14][15][16] and surface chemistry [17][18][19][20], but also the way of catalysts synthesis can affect the activity and/or selectivity [21,22].…”