Christina White's Awesome Webpage

On the White Lab webpage, multiple publicatins are posted for educatio and research purposes. I could not upload the picture for the reaction I chose to put on my blog but it can be  found at the following website:
http://www.scs.illinois.edu/white/index.php?p=publications
It is under publication #20. This reaction is an example of mixed hydroxylase/desaturase activity with a small molecule for unactivated, aliphatic C-H bonds outside the realm of enzymatic catalysis. The question is what causes the switch in Fe(PDP) from pure hydroxylase to mixed hydroxylase/desaturase activity reported in the presence of remote carboxylic acid moieties on the substrate. One hypothesis made by the White group is that it is the orientation of the iron oxidant [LnFe(OH)] relative to a key carbon centered radical intermediate on the substrate. In fact, in nature's oxidation enzymes, this radical intermediate is the gatekeeper from which all kinds of fascinating reactivities can be obtained such as hydroxylations, chlorinations, desaturations, rearrangements. Carboxylic acids, known to bind to Fe(PDP) and direct the site of substrate oxidation, may play a role in altering oxidant/substrate radical orientation. Because Fe(PDP) is stereoretentive (it doesn't scramble stereocenters during oxidation) the validity of this radical intermediate was up for debate. Prior to this work, many thought that this iron catalyst operated via direct, concerted C-H insertion (like the organic oxidant TFDO). If a concerted rather than a radical mechanism was operating, this, and other biomimetic reaction pathways, would not be accessible with Fe(PDP). To address this issue, a novel taxane-based radical trap that rearranges to nortaxane was used to provide the first direct evidence for a substrate radical intermediate. Interestingly, numerous biologically active nortaxanes have been isolated; however, there biogenic origins are controversial. This result suggests that radical-induced rearrangement of the taxane skeleton to nortaxane may be happening in nature during the oxidase phase of Taxol biosynthesis. Oxidation of Taxol in nature is performed by iron hydroxylation enzymes.