Transition metal-catalyzed olefin functionalization for highly regio-, enantio-, and chemoselective C–X bond formation

Kennemur, Jennifer L

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https://hdl.handle.net/2142/95581 Copy

Description

Title

Transition metal-catalyzed olefin functionalization for highly regio-, enantio-, and chemoselective C–X bond formation

Author(s)

Kennemur, Jennifer L

Issue Date

2016-11-23

Director of Research (if dissertation) or Advisor (if thesis)

Hull, Kami L.

Committee Member(s)

• Rauchfuss, Thomas B.
• White, M. Christina
• van der Donk, Wilfred

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• olefin functionalization
• rhodium-catalysis
• hydrothiolation
• hydroamination
• oxidative amination.

Abstract

The development of alkene functionalizations is an important challenge in modern catalysis.1 This thesis specifically focuses on using transition metal-catalysis to form C–X bonds from C–C double bonds with high degrees of regio-, chemo-, and stereoselectivity. In chapter 1, a regiodivergent Rh-catalyzed hydrothiolation of allyl amines to form 1,2- or 1,3-aminothioethers with excellent degrees of regioselectivity is reported. Bidentate phosphine ligands with larger natural bite angles (βn ≥ 99°) promote a Markovnikov-selective hydrothiolation in up to 88% yield and >20:1 regioselectivity. Conversely, when smaller bite angle ligands (βn ≤ 86°), are employed, the anti-Markovnikov product is formed in up to 74% yield and >20:1 regioselectivity. Initial mechanistic investigations are consistent with an oxidative addition/olefin insertion/reductive elimination mechanism for each pathway. We hypothesize that the change in regioselectivity is an effect of diverging coordination spheres to favor either Rh–S or Rh–H insertion to form the branched or linear isomer, respectively. In chapter 2, initial studies on an asymmetric hydroamination method for the highly enantioselective formation of a chiral 1,2-diamine are discussed. To our delight, we have identified a MeO-BIPHEP-type ligand that promotes the hydroamination of allyl amines in moderate yield with excellent enantioselectivity. Ligand discovery and initial optimization are described. Finally, in chapter 3, an anti-Markovnikov oxidative amination reaction of terminal olefins with pendent aryl- or alcohol functionality is presented. Alkenes are shown to react with imides in the presence of a palladate catalyst to afford the terminally aminated product. Following an anti-Markovnikov selective trans-aminopalladation, a thermodynamically-driven redox relay process occurs away from the newly formed C–N bond to afford a terminal Csp3–N bond and a ketone or styrene moiety. The functional group tolerance is explored and results of preliminary mechanistic investigations are shown.

Graduation Semester

2016-12

Type of Resource

text

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http://hdl.handle.net/2142/95581

Copyright and License Information

Copyright 2016 Jennifer Kennemur

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