Ph.D. 2011, Caltech with John E. Bercaw Prof. Ian A. Tonks B.A. 2006, Columbia University Ph.D. 2011, Caltech with John E. Bercaw P.D.F. 2012, University of Wisconsin-Madison with Clark R. Landis Assist. Prof. 2013, University of Minnesota Research interests : Using early transition metal catalysts for new redox reactions, and understanding how to access early transition metal redox manifolds.  Investigating cooperative effects in olefin polymerization toward new reactions such as CO2/ethylene copolymerization.  Exploring fundamental inorganic syntheses involving multimetallic and other potentially redox noninnocent regimes.

[2+2+1] Cycloaddition : Pauson-Khand Pauson-Khand reaction Many improvements and modifications arose with various metal catalysts (Fe, Ru, W, etc.) Gibson, S. E., Stevenazzi, A. Angew. Chem., Int. Ed. Engl. 2003, 42, 1800. I. U. Khand,G. R. Knox, P. L. Pauson, W. E. Watts, J. Chem. Soc. 1971, 36. I. U. Khand, G. R. Knox, P. L. Pauson, W. E. Watts, M. I .Foreman, J. Chem. Soc. Perkin Trans. 1973, 977. Son, S. U.; Choi, D. S.; Chung, Y. K. org. Lett. 2000, 14, 2097. F. A. Hicks, N. M. Kablaoui, S. L. Buchwald, J. Am. Chem. Soc. 1996, 118, 9450

[2+2+1] Cycloaddition : Pauson-Khand Hochimoto, Y.; Ohata, T.; Sasaoka, Y.;Ohashi, M.; Ogoshi, S. J. Am. Chem. Soc. 2014, 136, 15877. Fukuyama, T.; Nakashima, N.; Okada, T.; Ryu, I. J. Am. Chem. Soc. 2013, 135, 1006. Iwata, T.; Inagaki F.; Mukai, C. Angew. Chem. Int. Ed. 2013, 52, 11138.

Titanium Catalyzed Reactions Ackermann, L.;Sandmann, R.; Kaspar L. T. Org. Lett. 2009, 11, 2031 Kulinkovich, O. G.; Sviridov, S. V.; Vasilevskii, D. A.; Pritytskaya, T. S. Zh. Org. Khim. 1989, 25, 2244.

Titanium Catalyzed Reactions Ackermann, L.;Sandmann, R.; Kaspar L. T. Org. Lett. 2009, 11, 2031 Kulinkovich, O. G.; Sviridov, S. V.; Vasilevskii, D. A.; Pritytskaya, T. S. Zh. Org. Khim. 1989, 25, 2244.

Pyrroles MacDiarmid, A. G. Angew. Chem. Int. Ed. 2001, 40, 2581. Estévez, V.; Villicampa, M.; Menéndez J. C. Chem.Soc.Rev., 2014, 43, 4633. Hantzsch, A. Chem. Ber. 1890, 23, 1474. Paal, C. Chem. Ber. 1884. 17, 2756. Barton, D. H. R.; Zard S. Z. J.Chem. Soc. Chem. Comm. 1985, 10, 1098.

Tonks I. A.; Meier, J. C.; Bercaw J.E. Organometallics 2013, 32, 3451. Background Work Rothwell’s work : Titanacyclopentadiene and benzo[c]cinnoline to form pyrroles Bercaw’s work : Pyrrole formation as by-products during alkyne hydroamination Hill, J. E.; Fanwick, P. E.; Rothwell, I. P. Inorg. Chem. 1991. 30, 1144. Tonks I. A.; Meier, J. C.; Bercaw J.E. Organometallics 2013, 32, 3451.

Tonks I. A.; Meier, J. C.; Bercaw J.E. Organometallics 2013, 32, 3451. Background Work Tonks I. A.; Meier, J. C.; Bercaw J.E. Organometallics 2013, 32, 3451.

Preliminary Results and Optimization Azobenzene can oxidize low valent Ti species Hydroamination is competing with [2+2+1] TiII intermediate must be involved due to the [2+2+2]

Preliminary Results and Optimization Azobenzene can oxidize low valent Ti species Hydroamination is competing with [2+2+1] TiII intermediate must be involved due to the [2+2+2]

Preliminary Results and Optimization Azobenzene can oxidize low valent Ti species Hydroamination is competing with [2+2+1] TiII intermediate must be involved due to the [2+2+2]

Preliminary Results and Optimization Azobenzene can oxidize low valent Ti species Hydroamination is competing with [2+2+1] TiII intermediate must be involved due to the [2+2+2] No hydroamination products observed Both NPh units are incorporated in the product

Proposed Mechanism a

Mechanistic Investigation TiII reoxidation to an imido TiIV might involve a disproportionation of an η2 -azobenzene Crystal structure of 7 shows N-N bond length of 1.403 Å Thermolysis of 7 gives 1a and 0.5 eq. of azobenzene

Scope

Scope

Scope

Scope

Scope

Regioselectivity

Diazene Scope

Conclusions Catalytic formation of polysubstituted pyrroles was achieved New catalytic activity from a group 4 metal Good yields for unhindered alkynes but poor selectivity Lower yields for more hindered alkyne with better selectivity Regioselectivity is substrate controlled Weak substrate scope

Titanium Catalyzed Reactions Kulinkovich, O. G.; Sviridov, S. V.; Vasilevskii, D. A.; Pritytskaya, T. S. Zh. Org. Khim. 1989, 25, 2244.