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From “Abnormal” To “Normal”: The Study Of Reactivities Of Phosphaalkenes Towards N-Heterocyclic Carbenes And Other Nucleophiles

Date: 
Wednesday, October 16, 2019 - 17:00 to 18:00
Speaker: 
Zeyu Han
Affiliation: 
Department of Chemistry, University of British Columbia
Event Category: 
IDG - Inorganic Discussion Group
Host: 
Derek Gates
Location: 
Chemistry D300

Abstract:

The isolation of compounds featuring (3p–np)π bonds involving phosphorus stands as one of the earliest breakthroughs within the field of multiple bonding and low coordination for the p-block elements.[1] Our group has been interested in systematically developing various compounds containing P=C bonds (phosphaalkenes) and their addition polymerization as a route to new functional polymers.[2]

In an effort to investigate the polymerization of P=C bonds with potential initiators, some interesting reactivities of phosphaalkenes were discovered. For example, we reported the abnormal reactions of the NHCs with phosphaalkenes to afford 4-phosphinosubstituted NHCs.[3] Similarly, we also discovered the dimers of phosphaalkenes, 1,2-Diphosphetanes[4] reacted with NHCs to form 4-phosphinosubstituted NHCs. This type of abnormal reaction offers a convenient method to introduce new functionality at the backbone of an NHC.[5,6] We are interested in gaining insight into the mechanism of these unusual reactions. Kinetic studies, deuterium labelling experiments and computational studies have been conducted to get further information about the mechanistic pathway. Nevertheless, phosphaalkenes can also react “normally” with a variety of NHCs.[7] In these reactions, NHCs directly react with phosphaalkenes at the C2 position. Herein we are reporting several novel phosphaalkenes bearing various substituents and their reactivities towards NHCs and other nucleophiles.

 

References

1  a) Dillon, K. B.;  Mathey, F.; Nixon, J. F. Phosphorus: The Carbon Copy, Wiley, West Sussex,  

    England, UK, 1998; b) Mathey, F. Angew. Chem. Int. Ed. 2003, 42, 1578.

2  Bates, J.I.; Dugal-Tessier,J.; Gates, D. P. Dalton Trans. 2010, 39, 3151.

3  Bates, J. I.; Kennepohl, P.; Gates, D. P. Angew. Chem. Int. Ed. 2009, 48, 9844.

4  Wang, S.; Samedov, K.; Serin, S. C.; Gates, D. P. Eur. J. Inorg. Chem. 2016, 26, 4144.

5  Bates, J. I.; Gates, D. P. Organometallics 2012, 31, 4529.

6  Han, Z. Y.; Bates, J. I.; Strehl, D.; Patrick, B. O.; Gates, D. P. Inorg. Chem. 2016, 55, 5071.

7  Majhi, P. K.; Chow, K. C. F.; Hsieh, T. H. H.; Bowes, E. G.; Schnakenburg, G.; Kennepohl, P.; 

   Streubel, R.; Gates, D. P.  Chem. Commun. 2016, 52, 998.