Research

We love synthesis.  

We try to prepare hypervalent or low-coordinate phosphorus species OR transition metal complexes

supported by new multidentate phosphorus-derived ligands within a well-defined, high-energy geometry

with the goal of promoting strong bond activation that can be incorporated into a catalytic cycle.   

 

Project:  Hypervalent P

1.  Phosphinidene (R–P) Generation Within a Ligand Framework

Our first paper in which we tried to isolate a phosphinidene within an NCN pincer resulted in the discovery of an aromatic azaphosphole "bell-clapper". Dynamic scaffolds of this nature are rare, but were observed by J.C Martin (in the 1970s and 80s) during his investigations to isolate molecules featuring pentavalent carbons!  Check it out!

   

 

 

 

 

Our preliminary communication is reported here:

Hyvl, J.; Yoshida, W.Y.; Rheingold, A.L.; Hughes, R.P.; Cain, M.F.  Chem. Eur. J.  201622, 17562-17565.  DOI:  10.1002/chem.201604415

 

Related chemistry reported in a special issue in Polyhedron is reported here:

Hyvl, J.; Yoshida, W.Y.; Moore, C.E.; Rheingold, A.L.; Cain, M.F.  Polyhedron  2018, 143, 99-104.

If you cannot access these articles, email me and I will provide a PDF.

"Offshoot" Project:  New Pnictogen-Containing Heterocycles.  Azaphospholes and -arsoles.  

We discovered that if a P(I)/As(I) center was generated within a simpler NC chelate (rather than an NCN pincer) that a similar redistribution of electron density occurred, resulting in the synthesis of new PN and AsN heterocycles without the tethered imine donor.  These molecules are 10 pi-electron species that have demonstrated some interesting (soon to be published) reactivity.   

 

A full article on the synthesis of static aromatics, "bell-clappers", and hypervalent Group 15 derivatives,

new benzoazaphospholes and arsoles, and detailed calculations on their aromaticity can be found here:

Kremláček, V.; Hyvl, J.; Yoshida, W.Y.; Růžička, A.; Rheingold, A.L.; Turek, J.; Hughes, R.P.; Dostál, L.; Cain, M.F.

 Organometallics  2018, 37, 2481-2490.  DOI: 10.1021/acs.organomet.8b00290

If you cannot access this article, email me and I will provide a PDF.

Project: New Well-Defined Ligand Architectures

1.  Simple Bidentate Ligands:

A.  Phosphine-Phosphaalkene Hybrids

All of these targets were disclosed in our first paper in Organometallics that went online 3/16/2016

 

Magnuson, K.W.; Oshiro, S.M.; Gurr, J.R.; Yoshida, W.Y.; Gembicky, M.; Rheingold, A.L.; Hughes, R.P.; Cain, M.F.  Organometallics  201635, 855-859.  DOI: 10.1021/acs.organomet.6b00101

 

If you cannot access the article, email me and I will provide a PDF.  

B.  Pyridine-Phosphaalkene Hybrids

Nakashige, M.L.; Loristo, J.I.P.; Wong, L.S.; Gurr, J.R.; O'Donnell, T.J.; Yoshida, W.Y.; Rheingold, A.L.; Hughes, R.P.; Cain, M.F. Organometallics 2019, ASAP. DOI: 10.1021/acs.organomet.9b00425

2. Tetradentate Tris(phosphaalkene)phosphine ligands: Reactivity within an electron-rich Rh/Ir Pocket                                   

Coming soon ... Pincers? :)

 

 

See the publication tab for a list of all of our publications.  

 

Our new PP3 ligand and its corresponding metal complexes were reported in the following paper:

Miura-Akagi, P.M.; Nakashige, M.L.; Maile, C.K.; Oshiro, S.M.; Gurr, J.R.; Yoshida, W.Y.; Royappa, A.T.; Krause, C.E.; Rheingold, A.L.;

Hughes, R.P.; Cain, M.F.  Organometallics  201635, 2224-2231.  DOI:  10.1021/acs.organomet.6b00250

If you cannot access the article, email me and I will provide a PDF.

Mailing Address:

Cain Lab - Department of Chemistry

2545 McCarthy Mall - Bilger Hall

University of Hawaii at Manoa

Honolulu, HI 96822

Email Contact:

mfcain@hawaii.edu