Josh D. Sieber, Ph.D.
1001 W. Main St.
B.S., Chemistry, Penn State University
Ph.D., Chemistry, Boston College
American Cancer Society Postdoctoral Fellow, Stanford University
Research in the group is focused on the development of new catalysts and catalytic reactions for application to the synthesis of complex organic molecules. This consists of two main research areas:
New catalysts with improved robustness for application on industrial scale
Homogeneous catalysis is an enabling technology for the green synthesis of biologically important organic molecules. However, many transition metal catalyzed reactions suffer from high catalyst loading, which makes them impractical to employ on industrial scale due to the high cost of the metal and the difficulty associated with removal of the metal from the final product (i.e., tedious purification). This research is focused on developing new transition metal catalysts for organic synthesis that have improved robustness to allow for reduction in the transition metal catalyst loading for application to industrial scale. In this regard, new catalysts with these same properties utilizing the more naturally abundant and lower cost first row transition metals (i.e., Ni, Cu, Fe, etc.) are also of interest.
New catalysts for olefin activation
Alkenes represent abundant feedstocks that undergo rich chemistry for applications to organic synthesis. In particular, alkene functionalization through activation of the alkene towards nucleophilic attack represents a useful method for C-C bond formation and the installation of heteroatoms for alcohol or amine synthesis. The goal of this research is to develop new catalysts that can enable activation of alkenes towards nucleophilic attack and apply these methods in organic synthesis.
Sieber, J. D.; Rodriguez, S.; Frutos, R.; Buono, F.; Zhang, Y.; Li, N.; Qu, B.; Premasiri, A.; Li, Z.; Han, Z. H.; Xu, Y.; Byrne, D.; Haddad, N.; Lorenz, J.; et al. Development of a Scalable, Chromatography-Free Synthesis of t-Bu-SMS-Phos and Application to the Synthesis of an Important Chiral CF3-Alcohol Derivative in High Enantioselectivity Using Rh-Catalyzed Asymmetric Hydrogenation. J. Org. Chem. 2018, 83, 1448 – 1461.
Zhu, R. –Y.; Saint-Denis, Y. G.; Shao, Y.; He, J.; Sieber, J. D.; Senanayake, C. H.; Yu, J. –Q. Ligand Enabled Pd(II)-Catalyzed Bromination and Iodination of C(sp3)-H Bonds. J. Am. Chem. Soc. 2017, 139, 5724 – 5727.
Sieber, J. D.; Angeles-Dunham, V. V.; Chennamadhavuni, D.; Fandrick, D. R.; Haddad, N.; Grinberg, N.; Kurouski, D.; Lee, H.; et al. Rhodium-Catalyzed Asymmetric Allenylation of Sulfonylimines and Application to the Stereospecific Allylic Allenylation Adv. Synth. & Catal. 2016, 358, 3062 – 3068.
Sieber, J. D.; Qu, B.; Rodriguez, S.; Haddad, N.; Grinberg, N.; Lee, H.; Song, J. J.; Yee, N. K.; Senanayake, C. H. Synthesis of P-Chiral Dihydrobenzooxaphospholes Through Negishi Cross-Coupling. J. Org. Chem. 2016, 81, 729-736.
Chen, P. -H.; Sieber, J. D.; Senanayake, C. H.; Dong, G. Rh-Catalyzed Reagent-Free Ring Expansion of Cycobutenones and Benzocyclobutenones. Chem. Sci. 2015, 6, 5440-5445.
Sieber, J. D.; Chennamadhavuni, D.; Fandrick, K. R.; Qu, B.; Han, Z. S.; Savoie, J.; Ma, S.; Samankumara, L. P.; Grinberg, N.; Lee, H.; et al. Development of New P-Chiral P,-Dihydrobenzooxaphosphole Hybrid Ligands for Asymmetric Catalysis. Org. Lett. 2014, 16, 5494-5497.
Han, Z. S.; Goyal, N.; Herbage, M. A.; Sieber, J. D.; Qu, B.; Xu, Y.; Li, Z.; Reeves, J. T.; Desrosiers, N. –D.; Ma, S.; et al. Efficient Asymmetric Synthesis of P-Chiral Phosphine Oxides via Properly Designed and Activated Benzoxazaphosphinine-2-oxide Agents. J. Am. Chem. Soc. 2013, 135, 2474-2477.
Trost, B. M.; Xie, J.; Sieber, J. D. The Palladium Catalyzed Asymmetric Addition of Oxindoles and Allenes: an Atom-Economical Versatile Method for the Construction of Chiral Indole Alkaloids. J. Am. Chem. Soc. 2011, 133, 20611-20622.
Trost, B. M.; Sieber, J. D.; Qian, W.; Dhawan, R.; Ball, Z. T. Asymmetric Total Synthesis of Soraphen A: A Flexible Alkyne Strategy. Angew. Chem. Int. Ed. 2009, 48, 5478-5481.
Sieber, J. D.; Morken, J. P. Ni-Catalyzed Asymmetric Conjugate Allylation of Activated Enones. J. Am. Chem. Soc. 2008, 130, 4978-4983.