About a year ago I wrote a post on flow chemistry. That, broadly speaking, is the practice of doing reactions by pumping them through some sort of reaction zone, instead of putting everything into a flask and letting it rip.
There are refinements. In batch mode, you can of course add reagents in sequence, or trickle them in by slow addition. And there are several variations to flow chemistry - in my mind, I have three categories. Type I flow reaction, in my numbering, are the ones that don't depend on any reagents in the tubes themselves. Everything you need is in solution, and you're just using temperature and/or pressure to make them do what you want. Nucleophilic displacements and cycloadditions are in this category: mix up your starting materials, pump 'em down the hollow tube, and get your product out the other end. Ideally.
Type II flow reactions, then, are the ones that need some sort of solid-supported catalyst. Palladium couplings (or other metal-catalyzed processes) are a perfect example of this, as is the H-Cube hydrogenator. Now you have some solid matrix inside your tubing, and you're pumping material over that. Heat and pressure are still very much a part of things, but the catalyst is, too - and the advantage here is that it doesn't end up in your reaction mixture. Starting materials should go in, and product should come out, and you should be able to use the catalyst again. Ideally.
And Type III flow reactions, in my scheme, are the ones that need full equivalents (or more) of solid supported reagent. I think that the companies getting into flow apparatus should keep these in mind. That's because you're going to use these things up, eventually, and the companies involved will be able to sell you more. ("Give 'em the razor and sell 'em the blades", as King Gillette said). All sorts of chemistry might fall into this category - reductive aminations are the first thing that come to mind from a med-chem perspective. All sorts of reactions with nasty workups are candidates for this sort of approach.
But there's a catch, the dirty secret of flow chemistry from my experience so far: you know how we medicinal chemists sometimes have trouble making soluble compounds? Well, brace yourselves when you go with the flow reactors, because you're going to be clogging things up left and right. Any flow apparatus that does not take this into account should be regarded with suspicion: "easy to clean out" is a very desirable quality. Things have to be run more dilute than you think they do, and in stronger solvents. That can mean trouble on the back end, with more (and more difficult) solvents to get rid of in the isolation.
If anyone out there is also involved in the flow world and can talk about it, I'd be glad to hear some experiences. For bench-scale medicinal chemistry, the field is still in its early days, and there are lot of things that haven't been tried yet.