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Woods, Nolton Takashi

University of British Columbia

This thesis outlines the use of a phosphorus containing copolymer as a ligand for gold-catalyzed hydroaminations. Specifically, the phosphine moieties within the backbone of a random copolymer of styrene (S) and methylenephosphine (MP), PMP-co-PS function as P-ligands for gold(I) to afford a pre-catalyst. In Chapter 2, the use of the phosphorus-containing copolymer PMP-co-PS as a ligand for gold(I) is described. The activity of the acquired pre-catalyst PMP(AuCl)-co-PS in the intermolecular hydroamination of alkynes with arylamines (H₂NAr, Ar=Ph,4-NO₂Ph,etc.) is compared with the activity of model pre-catalysts (i.e., Ph₃PAuCl and MesP(AuCl)CHPh₂). Abstraction of the chloride from gold(I) using AgOTf was required for each pre-catalyst to obtain the active catalyst. In hydroaminations of phenylacetylene with arylamines employing pre-catalyst PMP(AuCl)-co-PS and following the above activation process selectively affords the Markovnikov products in good yields. In hydroaminations of diphenylacetylene with arylamines as substrates, the polymer-supported pre-catalyst was not as active; however, moderate yields of the imine and enamine product(s) were formed. Importantly, the polymer support allowed for the isolation of the catalyst from the products. The recovered catalyst could be recycled in additional cycles without the addition of fresh catalyst or AgOTf. It was determined that reducing the amount of gold(I) present to phosphorus in the polymer-supported pre-catalyst resulted in the improved stability of the active catalyst with sustained yields in the recycling reactions. In conclusion, PMP-co-PS was shown to be an effective support in gold catalysis that could be recovered and recycled for further use.

Text

2023-09-15

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/85921

Chemistry

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/