1. Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
2. Department of Chemistry and Biochemistry, Rowan University, Glassboro, New Jersey 08028, United States
3. Pfizer Global Research and Development, Eastern Point Road, Groton, Connecticut 06415, United States
4. Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, United States