Application of Metallocarbene Decomposed from Diazoesters with Organic Azides and 1,2,3-Triazoles

  • Author / Creator
    Niu, Tianmin
  • Metallocarbenes, in situ generated from catalytic decomposition of diazocarbonyl compounds, contain only 6 electrons at carbon center, therefore are highly electrophilic. Over the years, the metallocarbene intermediates have been continuously explored as a versatile tool toward C-C and C-X bond formations. An overview regarding the reactivities and typical transformations of metallocarbene species is discussed in Chapter 1. Chapter 2 discusses the use of organic azide as a nucleophile to intercept high-energy metallocarbene species. The α-imino ester was then generated in high yield. This transformation demonstrated a unique advantage over the traditional methods for α-imino ester synthesis since the only by-products are two equivalents of nitrogen gas. The subsequent trapping of α-imino esters with variety of carbon nucleophiles was also attempted to aim for generating α–quaternary amino esters; however, the process was not successful at the current stage. 1,2,3-Triazole compounds are one of the most important heterocycles in organic chemistry. From the past studies, these compounds are rather stable under oxidative, reductive, acidic and basic conditions due to its aromaticity. Chapter 3 illustrates a novel reactivity of stable 1,2,3-triazole compounds toward metallocarbenes, which process constructs a highly functionalized pyrroline-3-one heterocycles. A plausible reaction mechanism of this transformation has been rationalized yet inconclusive at current stage. The optimization and substrate scope of this reaction are detailed in Chapter 3.

  • Subjects / Keywords
  • Graduation date
    Spring 2016
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.