Hu Hongwen

Amino-functionalized silica-supported palladium catalysts and their applications in Heck olefination

Abstract Three amino-functionalized silica-supported palladium catalysts have been synthesized. These catalysts displayed high activity for the Heck reaction of iodobenzene with olefins. By using XXX—aminopyridine-palladium, a turnover number exceeding 16700 was observed for the reaction of iodobenzene with styrene or acrylamide. This catalyst can be recovered and reused by using tributylamine as base. It can also tolerate the presence of a variety of functional groups.

Vinylation of Alkyl Halides Catalyzed by Palladium Catalyst

Abstract The palladium catalyzed vinylation of alkyl halides, especially benzyl chlorides, with a variety of olefins has been studied. A possible free radical mechanism was proposed.

A Facile Approach to 2-Arylethylamines Via Polymeric Palladium Catalyst

Abstract 2-Arylethylamines were synthesized in moderate yields via Heck reaction of acrylamide with iodobenzenes in the presence of polymeric catalyst P-ph—phen. Pd (0) followed by hydrogenation and subsequent Hofmann reaction.

The Vinylation of 4′-Iodobenzocrown Ether Catalyzed by Polymeric Palladium Catalysts

Abstract The vinylation of 4′-iodobenzocrown ethers was achieved in good yields by using polymeric palladium catalysts P-Ph-Phen-Pd(reduced) and P-Ph-bpy-Pd(0).

[Poly(styryl)phenanthroline]palladium as heterogeneous catalyst for heck arylation using iodobenzene

Abstract The effects of different bases on Heck arylation catalyzed by the polymeric catalyst have been studied. The yield of product and the lifetime of the catalyst are influenced by the nature of the base used. The leaching of palladium from the polymeric catalyst is caused mainly by the competitive complexation of the ligands existing in the reaction media towards the metal. When tributylamine is replaced by DMF-H 2 O-NaOAc, the catalyst can be easily recovered and reused, the yields are higher and the products are found to be more pure. For the reaction of acrylamide with iodobenzene, even after ten consecutive runs the recovered catalyst still has high catalytic activity. In the DMF-H 2 O-NaOAc system, the catalyst can also tolerate the presence of a variety of functional groups; acrylamide could be introduced to react with substituted iodobenzenes in good yields.

[Poly(styryl)phenanthroline]palladium catalyst. Synthesis and some of its applications in vinylic substitution reactions with organic halides

Abstract A polymer-bound phenanthroline palladium catalyst, -ph-phen -Pd (reduced), has been synthesized although the precise form of the Pd has not yet been established unambiguously. The catalyst is very stable to air and moisture and can be stored for long periods. It was characterized by IR, DRS, ESCA, electron microscopy, and elemental analysis. The catalyst showed high activity for vinylic substitution reactions of iodobenzene with olefins. In general, smaller amounts of catalyst were used than those in homogeneous reactions, while the yields were about equal or a little higher. The catalyst can be recovered and reused, with tributylamine as the base: however, the catalytic activity was dramatically reduced after three runs as a result of leaching of palladium from the polymer support. Bromobenzene can also be induced to react with styrene using this catalyst in the absence of phosphine ligands.

A Convenient Preparation of Diamino Oligoethylene Glycols and Amino Polyethylene Glycols

Abstract Diamino oligoethylene glycols and amino polyethylene glycols were prepared in good yields by using the reaction of sodium diformamide with oligoethylene glycol or polyethylene glycol dichlorides or ditosylates followed by hydrolysis using ethanolic hydrochloride.

A convenient preparation of aminomethyl aryl ketones and their derivatives

Abstract A convenient preparation of N-phenacyl diformamides, N-phenacyl formamides and aminomethyl aryl ketone hydrochlorides from aryl bromomethyl ketones and sodium diformylamide was described.