Polyethylenimine (PEI), an organic branched or linear polyamine polymer, has been successfully used in the past for DNA complexation and transfection in vitro and in vivo into several cell lines and tissues. PEI was also applied in different fields from gene therapy and several studies have emphasized the importance of this polymer in medicinal chemistry. In this brief critical review the uses and applications of this versatile polymeric molecule will be discussed.

Near-infrared (NIR) fluorescence light has been applied to monitor several biological events in vivo since it penetrates tissues more efficiently than visible light. Dyes exhibiting NIR fluorescence and having large Stokes shift are key elements for this promising optical imaging technology. Here, we report the synthesis of a novel conjugate between a near-infrared indocyanine dye and an organic polyamine polymer (polyethylenimine, PEI) (IR820-PEI) with high chemical stability and good optical properties. IR820-PEI absorbs at 665 nm, emits at 780 nm, and displays a large Stokes shift (115 nm). Moreover, the reported conjugate is able to bind DNA, and the delivery process can be monitored in vivo with noninvasive optical imaging techniques. These characteristics make IR820-PEI one of the most effective and versatile indocyanine dye polymeric-conjugate reported so far.

Ferrocene derivatives have found many different uses and applications in organometallic chemistry, material chemistry, and catalysis. We have shown that using a catalytic amount (5–10 mol‐%) of commercially available indium tribromide, at room temperature, many carbon nucleophiles, such as indoles, allylsilane, enolsilane, silyl ketene acetal, diketone, and trimethylsilylcyanide, smoothly react with different optically active ferrocenyl alcohol derivatives to afford the desired products in high yield, with retention of configuration. Also, many different N‐nucleophiles (azide, carbamates) and O‐nucleophiles (alcohols) react as well, again with retention of configuration. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Catalyst sandwich: An efficient and sensitive high‐throughput‐screening method that uses sandwich immunoassays was developed and applied to the Sonogashira reaction. This new method is amenable to coupling reactions and allows the screening of more than 1000 catalyst samples per day.