Attention:

Certain features of Sigma-Aldrich.com will be down for maintenance the evening of Friday August 18th starting at 8:00 pm CDT until Saturday August 19th at 12:01 pm CDT.   Please note that you still have telephone and email access to our local offices. We apologize for any inconvenience.

ChemFiles

OrganoCatalysts

 
Vol . 2, 2002 Supplement
Grubbs' Catalysts & MacMillan's OrganoCatalysts™

Download PDF (641 KB)
Grubbs' Catalysts / MacMillan's OrganoCatalysts™ / Verkade's Superbases / Metal Catalysts and Ligands

MacMillan's OrganoCatalysts™

The vast majority of useful catalytic transformations involve inorganic or organometallic complexes as catalysts. Examples of catalysis by organic molecules can be found, but these examples are rare and have no general utility. OrganoCatalysis™ is a breakthrough technology, invented by Professor David MacMillan at Caltech, in which small organic molecules are designed and constructed to serve as general catalysts for asymmetric transformations of other substrates.

OrganoCatalysts™ have been successfully developed for several important reactions including the asymmetric variants of Friedel-Crafts alkylations,15 1,4 conjugate additions, Diels–Alder reactions,16 and 1,3 dipolar cycloadditions.17 These transformations enable an extremely broad range of chiral intermediates to be readily assembled (Scheme 8).


An interesting example employing RCM via Grubbs’ Catalyst in tandem with OrganoCatalysts™ is the three-step enantioselective synthesis of (-)-Ketorolac (Scheme 9). Ketorolac is currently manufactured in racemic form in a ten-step process. Studies of the pure (S)-enantiomer show enhanced biological activity and lower toxicity versus the racemic mixture.

OrganoCatalysts and OrganoCatalysis are trademarks of Materia, Inc.


56,976-3

(5S)-2,2,3-Trimethyl-5-phenylmethyl-4-imidazolidinone monohydrochloride

2g
56,977-1

(2S,5S)-2-(1’,1’-Dimethylethyl)-3-methyl-5-
phenylmethyl-4-imidazolidinone

2g