THE VAN VRANKEN GROUP
University of
California, Irvine
Research
Interests
The Van Vranken group studies and
develops chemical
reactions in two areas: peptide reporters of cell function and transition metal-catalyzed carbene insertions.
Our efforts to harness these patterns of reactivity have led to new tools for biology, new tools for synthesis, and new approaches to construction of natural products. Our group has developed concise routes to a range of bioactive natural products that include: AT-2433 A1 and B1; tjipanazoles F1, F2, C1, and C2; phakellistatins 3 and 13; madindolines A and B; corylifolin; and bakuchiol.
Peptide
Reprters of Cell Function
Peptides display reactive
functional groups that are
suseptible to selective modification. Many modifications lead to
strong visible fluorescence, for example formation of dityrosine
crosslinks and ditryptophan crosslinks discovered by our
group. Peptide sequence determines chemical reactivity in much
the same way that it determines protein structure. We are
identifying sequences that confer selective chemical reactivity towards
fluorogenic reagents. An additional goal of our research is to
develope selective small molecule reporters of MAP kinase activity.
Transition Metal-Catalyzed Carbene
Insertions
We are
also enganged in the
study of transition metal-catalyzed reactions that lead to insertion of
carbon atoms of one atom at a time. We have shown that iron and
palladium catalysts can catalyze the addition and rearangment of
carbenes, derived from diazo compounds, to allylic and propargylic
thioethers. We have extended this work, showing that palladium
can catalyze the insertion of carbenes into carbon-halogen bonds