Development of Molecular Sieves‐Supported Palladium Catalyst and Chemoselective Hydrogenation of Unsaturated Bonds in the Presence of Nitro Groups

Abstract

Abstract:The chemoselective hydrogenation of unsaturated bonds and azide functionalities is achieved in the presence of nitro groups by a heterogeneous palladium catalyst supported on molecular sieves (MS3A). The present method shows a widerange of applicability with regard to substrates and the catalyst can be easily prepared and reused at least three times without any loss of activity.

Development of a Palladium on Boron Nitride Catalyst and its Application to the Semihydrogenation of Alkynes

“…We have recently developed useful heterogeneous catalysts {e.g., Pd/C‐ethylenediamine complex [Pd/C(en)],29 Pd‐polyethyleneimine complex (Pd/PEI),30 Pd/C‐diphenyl sulfide complex [Pd/C(Ph 2 S)],31 Pd‐fibroin complex [Pd/Fib]32 and Pd‐molecular sieves complex (Pd/MS3 Å)33} possessing specific characteristics and suppressed catalytic activities to enable the chemoselective hydrogenation among various reducible functionalities such as N‐Cbz, benzyl ether, aromatic ketone, nitro, alkyne, alkene, azido and so on. Our suppression methodologies for the Pd catalyst’s activity are classified into two categories: (i) suppression by the coordination‐induced catalyst poisoning effect using the lone pairs of amines or sulfides,34 such as Pd/C(en), Pd/PEI35 and Pd/C(Ph 2 S), (ii) suppression due to the catalyst supports utilizing their characteristic properties as a material, such as Pd/Fib and Pd/MS3 Å.…”

Pt Nanoparticles Supported over Porous Porphyrin Nanospheres for Chemoselective Hydrogenation Reactions

“…In this regard it is noteworthy to mention that heterogeneous supports with metallic NPs catalyzed hydrogenation of olefins in the presence of nitro group is limited in literatures. Considering this, the report of Sajiki and co‐workers for Pd/Zeolite (MS‐3A, MS‐5A) composites provide valuable understanding for the selective hydrogenation of 4‐nitrostyrene to 4‐ethylnitrobenzene . Among other NPs based polymer supports, Haruta and co‐workers reported the activation of Pd on a conjugated porous polymer to monitor the selective conversion of 4‐nitrostyrene to 4‐ethyl nitrobenzene .…”

“…In Table 1 we have shown several hydrogenation products of 4nitrostyrene (NS), which are 4-ethylnitrobenzene (ENB), 4-vinyl aniline (VA) as partial hydrogenated products and 4-ethylaniline (EA) after complete hydrogenation. Highest selectivity (100 %) to 4-ethylnitrobenzene is observed for 75 % conversion of 4- [25] Among other NPs based polymer supports, Haruta and co-workers reported the activation of Pd on a conjugated porous polymer to monitor the selective conversion of 4-nitrostyrene to 4-ethyl nitrobenzene. [26] Again, Garcia and others showed the utilization of Pd and Au NPs on adamantane-based covalent organic frameworks for selective conversion of 4-nitrostyrene to 4ethylnitrobenzene.…”

Design and synthesis of 1-glycosyl-4-{N-[(2′-morpholinethoxy)- phenyl]aminomethyl}-1H-1,2,3-triazoles as calcium activators

“…Glycosyl azides(1a-1c) [15] and compounds 2a-2c [16] were prepared according to the literature procedures. Compounds were prepared according to the literature procedures [17][18][19] .…”