A co-entrapped mixture of [Rh(cod)Cl] 2 and Na[Ph 2 P-3-(C 6 H 4 SO 3 )] within a silica sol-gel matrix modified with ca. 5 % of 1-butyl-3-[3-(trimethoxysilyl)propyl]imidazolium chloride catalyzes, in n-heptane, the hydroformylation of a variety of vinylarenes. At 50°C and under 6.9 bar each of H 2 and CO the reaction is high-yielding and highly selective. Nonhindered substrates give Ͼ95 % of branched aldehydes and only Ͻ5 % of the linear isomers. The ceramic catalyst is leach-proof and recyclable. It does not lose its high catalytic activity and selectivity for at least four runs. The selectivity

[reaction: see text] Silica sol-gel encaged PdCl(2)(PPh(3))(2) is a recyclable catalyst for the Heck vinylation of aryl iodides. It is possible to couple the Heck reaction with photocyclization in a one-pot process.

We report on a one-pot, multistep process in which styrene derivatives are selectively hydroformylated to give branched aldehydes, which in turn, are condensed with reactive methylene compounds (malononitrile, ethyl cyanoacetate), and then hydrogenated. The process takes place at 80°C under 20.7 bar H 2 and 20.7 bar CO in the presence of [Rh(cod)Cl] 2

Silica sol‐gel encaged pyridinium hydrobromide perbromide can be used for clean, odorless bromination of a variety of substrates, including alkenes, ketones, and arenes. The used heterogenized bromination reagent can be recharged with bromine and recycled. In the presence of sol‐gel entrapped 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene, dibromides are dehydrobrominated to give vinyl monobromides and/or alkynes. Encapsulation of the pyridinium derivative and the guanidine base within separate sol‐gel matrices enables the use of both opposing reagents in one‐pot reactions without their mutual destroying each other. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

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