An Easy-To-Use, Regioselective, and Robust Bis(amidate) Titanium Hydroamination Precatalyst: Mechanistic and Synthetic Investigations toward the Preparation of Tetrahydroisoquinolines and Benzoquinolizine Alkaloids
作者:Zhe Zhang、David C. Leitch、Man Lu、Brian O. Patrick、Laurel L. Schafer
DOI:10.1002/chem.200600735
日期:2007.2.23
Amidate-supported titanium amido complexes are efficient and regioselective precatalysts for intermolecular hydroamination of terminal alkynes with primary amines. The synthesis and characterization of the first bis(amidate)-supported titanium-imido complex is reported. Its role as the active catalytic species is suggested in the course of product distribution studies using deuterated substrates. The bis(amidate)-supported
Effect of 1-Substitution on Tetrahydroisoquinolines as Selective Antagonists for the Orexin-1 Receptor
作者:David A. Perrey、Nadezhda A. German、Ann M. Decker、David Thorn、Jun-Xu Li、Brian P. Gilmour、Brian F. Thomas、Danni L. Harris、Scott P. Runyon、Yanan Zhang
DOI:10.1021/cn500330v
日期:2015.4.15
Selective blockade of the orexin-1 receptor (OX1) has been suggested as a potential approach to drug addiction therapy because of its role in modulating the brain's reward system. We have recently reported a series of tetrahydroisoquinoline-based OX1 selective antagonists. Aimed at elucidating structure-activity relationship requirements in other regions of the molecule and further enhancing OX1 potency and selectivity, we have designed and synthesized a series of analogues bearing a variety of substituents at the 1-position of the tetrahydroisoquinoline. The results show that an optimally substituted benzyl group is required for activity at the OX1 receptor. Several compounds with improved potency and/or selectivity have been identified. When combined with structural modifications that were previously found to improve selectivity, we have identified compound 73 (RTIOX-251) with an apparent dissociation constant (K-e) of 16.1 nM at the OX1 receptor and >620-fold selectivity over the OX2 receptor. In vivo, compound 73 was shown to block the development of locomotor sensitization to cocaine in rats.
Simplified Derivatives of Tetrandrine as Potent and Specific P-gp Inhibitors to Reverse Multidrug Resistance in Cancer Chemotherapy
Targeted inhibition of a drug efflux transporter P-glycoprotein (P-gp) is an important strategy to reverse multidrug resistance in cancerchemotherapy. In this study, a rationally structural simplification to natural tetrandrine was performed based on molecular dynamics simulation and fragment growth, leading to an easily prepared, novel, and simplified compound OY-101 with high reversal activity and