Making alkenyl halides

[haha123]

A recent article on making alkenyl halides stereoselectively using olefin metathesis: http://www.nature.com/nature/journal/v531/n7595/full/nature17396.html

Seems a decent alternative way of generating such compounds, especially fluorides.

What do you guys think?

[hypervalent_iodine]

Well, it's hard to go past a Hoveyda / Schrock paper. I believe some of those catalysts have previously been used for other types of Z selective CM type reactions. In fact, the Mo based ones were some of the earlier examples, and IIRC are used industrially for certain polymerizations. It's interesting that those would work better in these systems than the newer Grubbs variety.

[haha123]

Ya, the Mo catalyst is a slight modification of previously disclosed examples. It says it works better with Mo because Ru complexes are generally deactivated by halogen-substituted alkenes. From a synthesis standpoint, thought the cross-metathesis method is a good complementary to existing methods of making alkenyl halides. Will be interesting if trans-isomers could be synthesized too.

[hypervalent_iodine]

I believe they observed the E isomer with some of their catalysts.