ADVERTISEMENT
2 /3 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Synthesis

New Route To α-Alkylated Ketones

June 16, 2008 | APPEARED IN VOLUME 86, ISSUE 24

A new method for asymmetrically α-alkylating ketones—adding alkyl substituents to carbons adjacent to ketone groups to give chiral products—is simpler and more amenable to scale-up than current approaches, according to Duke University's Daniel Lim and Don M. Coltart, the researchers who devised the procedure (Angew. Chem. Int. Ed., DOI: 10.1002/anie.200800848). In the reaction, a ketone is combined with a chiral N-amino cyclic carbamate (ACC, red) to generate a hydrazone, which is then alkylated by an alkyl halide (purple) to yield chiral products and the original ACC. This approach also makes it possible for the first time to α,α-bisalkylate ketones asymmetrically. The technique could prove useful for modifying and synthesizing alkylated ketone structures found in many natural products and drugs. The method works at temperatures between −40 and 0 °C, and the ACC chiral auxiliaries used can be directly recycled to save costs. Both of these factors make scale-up more practical. In previous asymmetric ketone α-alkylations, colder reaction temperatures (−110 to −78 °C) were required and the chiral auxiliaries used were more difficult to recycle.

X

Article:

This article has been sent to the following recipient:

Leave A Comment

*Required to comment