My research work focused on the development of methodologies to enable efficient synthesis of natural products. In the Andrade lab I developed N-sulfinyl metallodienamine
(NSMD) and metalloenamine (NSME) methodologies for the asymmetric synthesis of
natural products. In 2017, our first report of a novel diastereoselective hydroxylation
protocol for metallodienamine (with 4:1 dr) in concise 14-step synthesis of (−)-albocycline
warranted further exploration of the method. By screening different metal bases, I was able
to observe a unique diastereoselective switch. DFT computational modeling assisted with
experimental analysis suggested a favoritism of metallodienamine geometry by choice of
metal bases as the origin of the diastereoselective switch. The method worked well with a
diverse set of N-sulfinyl aldimines and ketimines with 50-99% yield and 3:1 to 98:2
diastereoselectivity. A one-pot protocol was developed to access 1,2 amino alcohols with
high diastereoselectivity. With a good understanding of the diastereoselective reaction with
NSMD and NSMEs, I joined with Dr. Po-Cheng Yu to develop a highly diastereoselective
domino Michael/Michael/Mannich reaction for the concise total synthesis of (+)-
epiibogamine. The domino reaction enabled us to set all the stereocenters in the natural
product in a single step with high diastereoselectivity enabling access to the natural product
in a concise 7 steps. I also worked briefly on developing diastereoselective oxidative
coupling with N-sulfinyl imine for the synthesis of (+)-chimonanthine. At the beginning of
my fourth year I Joined the Kim lab, where I developed photoredox catalyzed process to
synthesize y-lactones. These motifs are found in various natural products and require
multistep to access. I developed a method that enables quick access to these motifs in one
step. / Chemistry
| Identifer | oai:union.ndltd.org:TEMPLE/oai:scholarshare.temple.edu:20.500.12613/9512 |
| Date | 08 1900 |
| Creators | Karmakar, Anupam, 0000-0003-4895-7015 |
| Contributors | Kim, Daniel K., Wengryniuk, Sarah E., Wang, Rongsheng, Beaudry, Christopher M. |
| Publisher | Temple University. Libraries |
| Source Sets | Temple University |
| Language | English |
| Detected Language | English |
| Type | Thesis/Dissertation, Text |
| Format | 335 pages |
| Rights | IN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available., http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | http://dx.doi.org/10.34944/dspace/9474, Theses and Dissertations |
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