Hi everyone,
I am performing McMurry coupling reaction of my carbonyl compound. After reaction completion and purification, I found that instead of McMurry dimer, the reduction of ketone happened (from NMR). My reaction condition was TiCl4 (4 eq.)/Zn (10 eq.) at 0°C for prolong time period. Please enlighten your experience!
Would magnesium help instead of zinc?
Thank you in advance!
I would say first make sure your glassware is ovendried or flamedried; water can hydrolyze your TiCl4 or can prematurely hydrolyze intermediates before dimerization can occur.
second, try to distill TiCl4 if you can and use right away for the same reasons as written above.
third, try refluxing your reaction in THF.
Dear Gaurang,
thank you for sharing this very interesting chemical question on RG. As a synthetic inorganic chemist I'm certainly not a proven expert in the field of organic synthesis. I think that Greg Petruncio already provided some useful hints. Did you follow a published procedure? In any case, it seems that hydrogenation of the ketone seems to be a rather common side reaction of the McMurry coupling. For more information, please have a look at the following potentially useful article:
Hydrogenation and Other Side-Reactions During the Reductive Coupling of Ketones with Lowvalent Titanium (McMurry Synthesis)
Article Hydrogenation and Other Side-Reactions During the Reductive ...
Unfortunately this paper has not been posted as public full text on RG. Perhaps you can access it through your institution.
Good luck with your work!
Greg Petruncio I've prepared McMurry products before. So I am aware of all drying conditions. This system is slight different than previous one. However, I'll try to reflux the reaction as you've suggested. Thank you so much sir for your suggestions.
I would also like to thank prof. Frank T. Edelmann for his valuable suggestion. I'll look into the article that you've provided. Thank you sir.
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