Indiana University-Purdue University Indianapolis (IUPUI) / The C-O single bond is found in numerous functional motifs including carboxylic acids,
alcohols, and ethers. These compounds represent ideal precursors towards C-X (X = C, H, or
heteroatom) bond formation due to their inherent stability and abundance in nature. As such,
synthetic chemists continue to develop new technologies for the transformation of these
precursors into biologically useful targets such as amides and amines. However, due to the
stability of the C-O single bond, accessing such targets remains a consistent challenge. The
activation of the carboxylic acids towards peptide synthesis has been facilitated through
various coupling agents, including organoboron and transition metal catalysts. However,
coupling agents can generate stochiometric, difficult-to-remove, toxic waste by-products.
Organoboron/transition metal catalyzed condensations offer a more atom economical approach
but suffer from varying degrees of optical erosion and poor sustainability. Phosphonium-based
deoxyaminative technologies provide access to amines from alcohols via a phosphorus oxygen
double bond formation driving force, but possesses a narrow nucleophilic nitrogen source
scope, and poor atom economy. Transition metal/enzyme catalyzed “hydrogen borrowings”
represent atom economical deoxyaminative alternatives. Still, their respective use of costly
metals, and multiple enzymatic cascade steps severely limit the sustainability and scope of
such protocols.
An ambient deoxyamidation of carboxylic acids and deoxyamination of alcohols was
developed through the use of N-haloimides activated by triphenylphosphine. Such
technologies were found to possess broad functional tolerance and formed C-N bonds via a
coupling to free amines, and the direct installment of the imide motif. Mechanistic experiments
suggest that such transformations take place via the in situ generation of two separate
phosphonium reactive species.
| Identifer | oai:union.ndltd.org:IUPUI/oai:scholarworks.iupui.edu:1805/33380 |
| Date | 05 1900 |
| Creators | Irving, Charles D. |
| Contributors | Laulhé, Sébastien, Manicke, Nicholas, Minto, Robert, Deng, Yongming |
| Source Sets | Indiana University-Purdue University Indianapolis |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
Page generated in 0.0017 seconds