Chemistry that tugs at the heartstrings

Baeyer-Villiger has always been one of my favorite reactions, owing to the double coolness of the use of peracids and an alkyl migration in the mechanism. Malkov et al. have written a very nice JOC paper describing the enantioselective preparation of lactones from prochiral cyclic ketones using the Baeyer-Villiger reaction, complete with a rich history of recent chemistry in the area. They don’t actually use a peracid as oxidant, opting instead for UHP (urea-hydrogen peroxide), but this slight coolness deduction is more than made up for by their use of palladium catalysis. Using chiral P,N-ligands (derived, interestingly, from terpenes), they were able to obtain up to 80% ee of chiral gamma lactones, more or less state-of-the-art for asymmetric B-V reactions. Procedures for making the ligands and even the cyclobutanone starting materials are included right there in the paper! Woohoo!

Aside: here’s to hoping that when some poor grad student googles “state of the art baeyer-villiger,” they end up here.

There’s an odd double-slash mark next to the title of the paper, which links to a dedication to the memory of Otto Exler. I’ve read a lot of papers in my day, and I’ve honestly never seen that before. Call me sentimental, but I thought it was nice. See? Not all scientists are heartless!

For the mechanistically thirsty, this paper discusses intermediates involved in a few variants of the asymmetric B-V reaction.

And last but not least: happy end of the semester everybody!

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10 Comments

  1. Whew, I’ve got a pretty busy night tomorrow. I’ll try to make it though…just let me know where you end up!

    Reply

  2. Its more properly called Kocovsky et al paper. He is the professor in the Glasgow group and this is one of his favorite ligands.

    Reply

  3. j-hell yes you can come!

    ashutosh-I rarely read angew, usually only the ACS journals…

    milkshake-thanks for the info!

    p*p-sounds good,

    And last but not least, THANKS FOR THE COMMENTS 😀

    Reply

  4. It’s end of the semester for you? Like, all the finals are done and over?

    Lame. My ending is just beginning.

    Reply

  5. I’ve actually done one of these types of reactions using the peroxy acid. It is effing badass. Add a little base, toss in the acid, let it stir overnight, and bam, you got yourself a lactone.

    Unfortunately, I think I got two regioisomers which were inseparable, and the next step in the synthesis blew, but still, the B-V was badass nonetheless.

    Reply

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