PART I. EXTENDING ALLENYL AZIDE CYCLOADDITION CHEMISTRY: PHOTOCHEMISTRY AND CU(I) MEDIATION. PART II. EFFORTS TOWARD THE TOTAL SYNTHESIS OF (-)-KINAMYCIN F. PART III. EFFECT OF STRENGTH AND SYMMETRY OF HYDROGEN BONDS ON QUINONE REDUCTION POTENTIAL.

Open Access
Author:
Hester II, David Keith
Graduate Program:
Chemistry
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
September 12, 2008
Committee Members:
  • Ken S Feldman, Committee Chair
  • John H Golbeck, Committee Chair
  • Steven M Weinreb, Committee Member
  • Ming Tien, Committee Member
Keywords:
  • methodology
  • synthesis
  • photosystem I
  • internally hydrogen-bonded quinone
  • indolidene
  • kinamycin
  • fischerindole
  • Allenyl Azide
  • photochemistry
Abstract:
Photochemical irradiation of 2-(3-alkenyl)allenylphenyl azides in the presence of excess CuI furnished functionalized 2,3-cyclopentenylindoles in good yield with only trace amounts of C-N bonded regioisomers. These results represent a significant departure from the modest-to-nonexistent regioselectivity observed upon thermolysis of these same substrates. The scope and limitation of this methodology is discussed. Mechanistic insight was aided by a collaborative effort with DFT computational models. These studies suggest that the allenyl azide cyclization cascade proceeds through a highly reactive indolidene intermediate. A synthetic effort toward the synthesis of the fischerindole class of natural products utilizing this methodology is also discussed. A total synthesis effort toward the diazoparaquinone natural product (-)-kinamycin F is reported. A strategy utilizing a Hauser annulation to assemble the core tetracycle is employed. A series of 11 simple naphthoquinone derivatives featuring H-bond donor amides at one or both peri positions were prepared and some salient physical properties were measured. A correlation between both IR frequency and NMR peak position, as indicators of internal H-bond strength, and the quinone single electron reduction potential was observed.