Anti-Markovnikov Hydroarylation of Unactivated Olefins via Pyridyl Radical Intermediates
作者:Allyson J. Boyington、Martin-Louis Y. Riu、Nathan T. Jui
DOI:10.1021/jacs.7b03262
日期:2017.5.17
The intermolecular alkylation of pyridine units with simple alkenes has been achieved via a photoredox radical mechanism. This process occurs with complete regiocontrol, where single-electron reduction of halogenated pyridines regiospecifically yields the corresponding radicals in a programmed fashion, and radical addition to alkene substrates occurs with exclusive anti-Markovnikov selectivity. This
Structure−Activity Relationships of (<i>E</i>)<i>-</i>3-(1,4-Benzoquinonyl)-2-[(3-pyridyl)- alkyl]-2-propenoic Acid Derivatives That Inhibit Both 5-Lipoxygenase and Thromboxane A<sub>2</sub> Synthetase
As part of our research for the development of novel antiinflammatory drug candidates, we have designed and synthesized a series of (E)-3-(1,4-benzoquinonyl)-2-[(3-pyridyl)alkyl]-2-propenoic acid derivatives as dual inhibitors of 5-lipoxygenase (5-LO) and thromboxane (TX) A(2) synthetase. In order to increase the absorption after oral administration, we introduced a carboxylic acid moiety into the 1,4-benzoquinone skeleton, which has 5-LO-inhibitory character. Introduction of a 3-pyridylalkyl group at the double bond of the 1,4-benzoquinonyl propenoic acid moiety afforded good to moderate inhibitory activities against the production of leukotriene (LT) Bq and TXA(2) while not significantly inhibiting that of prostaglandin E(2) by glycogen-induced peritoneal cells of rat (in vitro). The length of the methylene chain of the 3-pyridylalkyl group influenced the inhibition of LTB(4) and TXB(2) production. An increase of lipophilicity by introducing a more lipophilic alkoxy group did not markedly increase the inhibitory activity on LTB(4) production. The position of an alkoxy group on the 1,4-benzoquinone skeleton played an important role in TXA(2) synthetase inhibition. Compounds such as 20c (E6700) with an appropriate alkoxy group and proper length of methylene side chain, together with a polar substituent (carboxylic acid), showed good inhibition of both 5-LO and TXA(2) synthetase and possess a variety of pharmacologically beneficial effects.
TILLEY J. W. LEVITAN P.; LIND J.; WELTON A. F. CROWLEY H. J.; TOBIAS L. D+, J. MED. CHEM., 30,(1987) N 1, 185-193
作者:TILLEY J. W. LEVITAN P.、 LIND J.、 WELTON A. F. CROWLEY H. J.、 TOBIAS L. D+