CURE-ious Chemistry
Continued from page 21
Since completing the class last spring , Cooke , now Eskew ’ s teaching assistant , continues to dedicate her time to the garden each Sunday . “ It is a unique experience in that it is inter-generational ,” she says . “ On campus , I do not get the opportunity to interact with people who are in different stages of their life , but community members and grad students come to the garden . Gardening is a lot of work with your hands so there is plenty of time to chat .”
Inspiring Others
During her own undergraduate career at Carolina , Eskew , a first-generation college student , never knew about research opportunities until her adviser suggested she pursue it one summer . She did not have any family or friends who were chemists , nor did she understand what chemists did outside the academic environment . This meant graduate school was not originally in the cards for her either , Eskew admits , but that same adviser encouraged her to apply .
“ By the end of that summer doing research , I was hooked with discovery and learning something new , and realizing that other people had never made the compounds I did or seen their reactions ,” she says . “ That is why I think this class is a great opportunity to give students a small introduction into what research is , especially for those who are first-generation or have never been exposed to research .”
“ Dr . Eskew is a really special person here at Carolina ,” Cooke adds . “ It is admirable that she put so much time into creating this class , and how dedicated she is to her students . I think getting research experience is one of the most important things during your undergraduate career . It has changed the way I think . To be put in a setting where no one in the room really knows the answer , and it is okay to not know the answer , that is great .”
Selective Transformations
The selective , and controllable , modification of complex molecules with disparate functional groups , for example , natural products , is a long-standing challenge that has been addressed using catalysts tuned to perform singular transformations , for example , C – H hydroxylation .
In research published in Nature Chemistry , and also highlighted in ChemistryWorld , researchers in the Gagné Group demonstrate silylium ions combined with reducing counterions to forge chemoselective transformations on complex bioactive compounds .
Fluoroarylborane catalysts can heterolytically split Si – H bonds to yield an oxophilic silylium , R 3
Si + , equivalent along with a reducing , H – , equivalent . Together , these reactive intermediates enable the reduction of multiple functional groups .
Exogenous phosphine Lewis bases further modify the catalyst speciation and attenuate aggressive silylium ions for the selective modification of complex natural products . Manipulation of the catalyst , silane reagent and the reaction conditions provides experimental control over which site is modified , and how .
The ability to carry out varied and selective transformations under catalyst control across diverse natural product structures suggests that it will emerge as a powerful tool for the synthesis of new chemical entities that encircle the structure of natural products and drug candidates . Whether these structures have resulted from traditional medicinal chemistry , screening of natural product , fully synthetic libraries or diversity-oriented synthesis , the chemistry described in this publication will enable those hits to be diversified further , even if the substrates are already complex .
CHEM . UNC . EDU | CHEMISTRY AT THE UNIVERSITY OF NORTH CAROLINA | 23