Fibrous apatite has been grown by the enzymatic hydrolysis of calcium beta-glycerophosphate on reconstituted calfskin collagen tapes which had been modified by the addition of a phosphoprotein, phosvitin, in the presence of a cross-linking agent, dimethylsuberimidate. The deposits were identified as a carbonate-bearing hydroxyapatite by x-ray diffraction, and scanning electron micrographs confirmed their fibrous character.

Positive reinforcement: The composite catalytic‐dopant@catalytic‐metal (an organic catalyst entrapped within a catalytic metal) synergistically outperforms the combined activities of each individual catalyst. Specifically, the dual catalytic activity of Nafion@Pd is investigated by combining elimination with either hydrogenation or disproportion in a one‐pot, two‐catalytic‐step process, which proceeds to completion with only the catalytic composite.

The extraction of the two competing reactions from the same catalyst-a composite catalytic-complex@catalytic-metal-is reported.AWilkinson rhodium based catalyst entrapped within metallic palladium catalysti ss hown to perform both hydroformylation and hydrogenation with ar atio that depends on H 2 and CO pressures. Here we demonstrate this special reactivity in ao ne-pot, four step sequence, which include hydroformylations of phenyla cetylenes, reduction of nitrobenzene to aniline, carbonyl-amine condensations formingi mines;a nd imine reductions.

No abstract

We report the feasibility of the catalysis of contrasting reactions, oxidation and reduction, in a multistep process that also involves a condensation reaction all performed with hybrids of catalytic organometallic complexes entrapped within metals ([complex]@metal). Two routes were explored for the multistep process. The first route used a combination of an oxidizing Ir complex entrapped in Ag ([Ir]@Ag) and a reducing Rh complex entrapped in Ag ([Rh]@Ag). The second route used a single composite material, namely, [Ir]@Pd, in which [Ir] acted as the oxidizing catalyst, and Pd was the reducing catalyst. Both routes were efficient for the heterogeneous catalytic oxidation and reduction reaction sequence. Towards the goal of a one‐pot multistep oxidation and reduction process, a detailed study of the catalytic alcohol oxidation properties of the heterogeneous [Ir]@Ag and [Ir]@Pd was performed. As the arsenal of available hydrogenation catalysts exceeds by far that of oxidations, this part of the study is, we believe, of general interest in itself, as a new alternative to heterogeneous oxidative catalysis.