See, Xin Yi2020-08-252020-08-252020-05https://hdl.handle.net/11299/215082University of Minnesota Ph.D. dissertation.May 2020. Major: Chemistry. Advisor: Ian Tonks. 1 computer file (PDF); xxv, 337 pages.This thesis broadly covers our catalyst development efforts for selective Ti(II)/Ti(IV) redox catalysis towards the synthesis of multi-substituted pyrroles. Chapter 1 provides a literature background on the multitude of ways to access low-valent early transition metals and its application towards group transfer catalysis. Chapter 2 describes the synthesis of pyrroles from the [2+2+1] coupling of alkynes and azides mediated by simple Ti-halide catalysts. Chapter 3 covers the generality of accessing Ti(II) intermediates, in the absence of strong metal reductants, via the coupling of Ti(IV) imido precatalysts and alkynes. Lastly, Chapter 4 details utilizing iterative supervised principal component analysis as a strategy to aid in rational catalyst design in the Ti-catalyzed regioselective synthesis of pyrroles.enCatalysisInorganicOrganometallicThesis or Dissertation