TY  - UNPB
ID  - pittir20815
UR  - http://d-scholarship-dev.library.pitt.edu/20815/
A1  - Li, Xiben
Y1  - 2014/05/29/
N2  - This thesis deals with the development of new reaction methodology, as well as total synthesis of natural products.
Chapter 1 describes readily available rhodium(II) salts catalyzed B-H insertion reactions between NHC-boranes (NHC-BH3) and diazocarbonyl compounds (N2CR1COR2). Stable ?-NHC-boryl carbonyl compounds (NHC-BH2-CHR1COR2) are isolated in good yields. The reaction is a reliable way to make boron-carbon bonds with good tolerance for variation in both the NHC-borane and diazocarbonyl components. It presumably occurs by insertion of a transient rhodium carbene into a boron-hydrogen bond of the NHC-borane. Competition experiments show that a typical NHC-borane is highly reactive toward rhodium carbenes.
Chapter 2 describes the synthetic routes towards the synthesis of tulearin A and tulearin C. Large scale synthesis of the bottom fragments (C1-C12) and the top fragment (C13-C26) for tulearin A was accomplished. Different synthetic routes were tested to accomplish the total synthesis of tulearin A. Some major problems toward the total synthesis of tulearin A were identified and solved. Meanwhile a novel synthetic route towards the total synthesis of tulearin C was developed. New methodologies were applied to make the synthesis more efficient. The total synthesis of tulearin C was not accomplished because of the difficulty of removal of the acetate protecting group at C17.
KW  - Boron-Hydrogen bond insertion
KW  -  NHC-Boranes
KW  -  Total synthesis
KW  -  Tulearins
TI  - Endeavors in Methodology Development and Natural Product Total Synthesis
EP  - 182
AV  - public
ER  -