THE ROLE OF STERICS AND ELECTRONICS ON NICKEL CATALYZED ISOMERIZATION OF ALLYLBENZENE

Abstract

Alkenes are a ubiquitous chemical functional group that serve as starting materials for a variety of industrially relevant chemicals in the pharmaceutical, synthetic manufacturing, and fragrance industries. One way of controlling alkene positionality and geometry is through metal–catalyzed isomerization. Current academic research focuses heavily on precious metals such as platinum, ruthenium, and iridium which are expensive and have been seen to promote side reactivity. In this project, the earth abundant metal, nickel, is used as a cheap alternative to its more costly counterparts. Four nickel complexes have been synthesized and characterized by following and improving established literature protocols. The complexes were subjected to isomerization conditions with the model substrate allylbenzene to determine the role of sterics and electronics on overall yield, product distribution, E/Z ratio, and initial rate of reaction. No trends were seen with regards to product distribution, overall yield, or E/Z ratio. The initial rate of reaction, however, was seen to increase with respect to steric encumbrance, contrary to the proposed hypothesis that increasing sterics would decrease initial rate of reaction.