This is a minireview where the authors focused on the implementation of metathesis catalysts "in specialty-chemicals and pharmaceutical manufacturing". I think it is a very useful review. In particular, I like the details like the effect of impurity (and what they are). These impurities are not only coming from the previous steps or starting materials but they are also some of the undesired side-products of metathesis. Early metals such as Mo and W tend to cleave and make new bonds. So, as you can imagine there is a lot more going on these reactions.
There is also nice table where you can see a long list of ring closing metathesis (RCM) catalysts and their industrial application. Finally, there are several examples of RCM, the challenges and some nice discussion about their activity and selectivity.