A recent paper of Prof. Fumitoshi Kakiuchi et al. (from Keio University in Yokohama, Japan) deals with the copper-catalysed α-chlorination of 1,3-dicarbonyl compounds.
You might be thinking that it is just another paper on an overused method, but there is a twist here that I particularly liked. The source of chlorine here is nothing but hydrochloric acid, probably the cheapest and simplest source of chlorine atoms, without the issue of handling a toxic gas like Cl2. I guess there is no point in mentioning N-chlorosuccinimide. The trick for the transformation of a fairly inert Cl– into a formal Cl+ is the use of electrochemistry. A mild current at the appropriate intensity provides just enough oxidation to provide monochlorinated 1,3-dicarbonyls in ok-to-high yields.
While I doubt I will ever use this method in a lab (I am not too experienced with organic electrochemistry), I can see the potential of it on an industrial scale: reducing costs of reagents, reducing waste, and perhaps you could even use the H2 produced by the reaction to power an auxiliary generator or something.