Novel usage of palladium complexes with P-N-P ligands as catalysts for diphenyl carbonate synthesis

Abstract

Two palladium complexes with P-N-P ligands [Pd{(SPPh 2 ) 2 N} 2 ]{Pd(S,S)} and [Pd{(SePPh) 2 N} 2 ]{Pd(Se,Se)} were prepared and investigated as novel polladium catalysts for oxidative carbonylation of phenol using carbon monoxide and oxygen along with a redox catalyst (for in situ regeneration of palladium) and ammonium halide. The efficiency of these new catalysts was compared with that of a PdCl 2 -based catalyst system. In order to obtain the maximum efficiency, the effects of various parameters such as concentration of redox catalyst and ammonium halide, the effect of solvent, the influence of a quinone-type redox catalyst in addition to inorganic redox catalyst, and the effect of temperature were studied. Under the reaction conditions employed, the Pd(S,S) catalyst was found to perform better than PdCl 2 -based catalyst system, whereas the Pd(Se,Se) catalyst had extremely low efficiency.

A new, nonphosgene route to poly(bisphenol a carbonate) by melt‐phase interchange reactions of alkylene diphenyl dicarbonates with bisphenol A

“…The second process uses DPC, prepared initially from phosgene and phenol,2, 9, 10 as a carbonate‐providing compound for BPA transesterification. To avoid the use of DPC generated from phosgene, the direct synthesis of DPC from phenol and carbon dioxide has been given considerable attention 11–18. Nonphosgene methods of preparing DPC to overcome the drawbacks have been reported, and the subject has been reviewed 3, 19–21…”

Catalytic Polymerization and Post Polymerization Catalysis Fifty Years After the Discovery of Ziegler's Catalysts

“…Extensive research has been conducted to optimize the palladium catalysts. [273][274][275][276][277][278][279] The preferred catalysts comprise palladium-tin complexes, palladium bipyridyl complexes and diimine-palladium complexes. Although the diphenyl carbonate route offers obvious advantages, the progress in the one-step polycarbonate synthesis via oxidative carbonylation of bisphenol was quite remarkable as reflected by improving the number average molecular weights of polycarbonate into the range around 5 600 g/mol and polydispersities of 2.…”

“…While in conventional phosgene free transesterification processes phosgene is still needed to make diphenyl carbonate, the formation of diphenyl carbonate by oxidative carbonylation followed by transesterification and recycling of phenol back into diphenyl carbonate is a truly phosgene free process. Extensive research has been conducted to optimize the palladium catalysts 273–279. The preferred catalysts comprise palladium‐tin complexes, palladium bipyridyl complexes and diimine‐palladium complexes.…”

On horse sense and horse feathers: An argument against insistence on enrolling cryptogenic stroke patients with patent foramen ovale in randomized clinical trials

“…Although polymeric ligands with a PCP framework were prepared and shown by Bianchini and coworkers14, 15 to be useful, analogous diphosphinoamine ligands with a PNP framework have not been linked to polymeric systems. The most attractive features of diphosphinoamines are the ease with which a variety of ligands can be synthesized by the alteration of the substituents on nitrogen and phosphorus16–19 and their use in transition‐metal‐catalyzed hydrogenation,20–22 hydroformylation,23 copolymerization,23, 24 Pauson Khand reactions,25 olefin polymerization,26–29 dehydrogenative coupling of stannanes,30 ring‐opening polymerization of lactones,31 diphenyl carbamate synthesis,32 and ring‐opening metathesis 33. Recently, Braunstein et al34 reported a diphosphinoamine system anchored to alumina.…”