Type
Text
Type
Dissertation
Advisor
Kerber, Robert | Ojima, Iwao | Goroff, Nancy | Gupta, Ramesh.
Date
2013-12-01
Keywords
Chemistry | allocolchicinoid, asymmetric synthesis, biphenol-based phosphorus ligand, colchicinoid, rhodium-catalyzed cycloaddition
Department
Department of Chemistry.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/77104
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Chiral ligand design is crucial for the asymmetric transformations. In our laboratory, libraries of fine-tunable phosphorus ligands based on axially chiral biphenol have been well developed. These ligands exhibit excellent enantioselectivity in various transition-metal catalyzed asymmetric reactions. We present here the application of the monodentate phosphoramidite (MPN) ligand library to the Pd-catalyzed intramolecular asymmetric allylic amination (AAA) for the formation of chiral 1-vinyltetrahydroiso-quinoline skeleton, a versatile key intermediate in the synthesis of natural products such as isopyruthaline and (− )-O-methylthaicanine. We also studied the Pd-catalyzed inter-molecular AAA reaction using our bidentate diphosphonite (BOP) ligands. The BOP ligands exhibit excellent efficacy in this reaction, which provides a key intermediate for the total synthesis of Strychnos indole alkaloids. The non-benzenoid aromatics, tropones and tropolones, are found in various natural products such as colchicine and hinokitol, which possess significant biological activities. The traditional methods to construct the tropone skeletons include oxidation of cycloheptatriene and [4+3] cycloadditions. In addition, the total synthesis of colchicine and its analogues requires laborious organic transformations in the formation of 6-7-7 fused rings systems. Transition metal-catalyzed carbocyclization and cycloaddition reactions have proven to be among the most efficient methods for constructing complex polycyclic systems. Rh-catalyzed carbocyclizations (i.e. SiCaC, SiCaT, CO-SiCaT) and higher order cycloaddition reactions can give novel fused-cyclic products. We present here the application of Rh-catalyzed [2+2+2+1] cycloaddition to the one-step formation of the 6-7-7-5 fused-tetracyclic scaffold of colchicinoids. Furthermore, a microwave-mediated Rh-catalyzed [2+2+2] cycloaddition to synthesize the allocolchicinoids was developed as well. | 327 pages
Recommended Citation
Chien, Chih-Wei, "(I) Synthesis and Application of Chiral Biphenol-Based Phosphorus Ligands to Catalytic Asymmetric Synthesis; (II) Rhodium-Catalyzed Cycloaddition Reactions for Rapid Construction of Polycyclic Skeletons of Biological Interest" (2013). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2941.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2941