African trypanosomiasis: Synthesis & SAR enabling novel drug discovery of ubiquinol mimics for trypanosome alternative oxidase
作者:Ryan A. West、Oran G. O'Doherty、Trevor Askwith、John Atack、Paul Beswick、Jamie Laverick、Michael Paradowski、Lewis E. Pennicott、Srinivasa P.S. Rao、Gareth Williams、Simon E. Ward
DOI:10.1016/j.ejmech.2017.09.067
日期:2017.12
millions of livestock animals in sub-Saharan Africa every year. Current treatments are limited, difficult to administer and often toxic causing long term injury or death in many patients. Trypanosome alternative oxidase is a parasite specific enzyme whose inhibition by the natural product ascofuranone (AF) has been shown to be curative in murine models. Until now synthetic methods to AF analogues have been
Described herein is the enantioselective synthesis of multisubstituted biaryl derivatives by chiral phosphoric acidcatalyzed asymmetric bromination. Two asymmetric reactions (desymmetrization and kineticresolution) proceeded successively to afford chiral biaryls in excellent enantioselectivities (up to 99% ee). Both experimental and computational studies suggested that this excellent selectivity
Synthesis of the alkenyl-substituted tetracyclic core of the bisabosquals
作者:Jingye Zhou、Mercedes Lobera、Bobbianna J. Neubert-Langille、Barry B. Snider
DOI:10.1016/j.tet.2007.07.033
日期:2007.10
HCl-catalyzed deprotection and cyclization of benzylic alcohol 15 cleanly provided tricycle 16 by a cis-selective intramolecular Diels-Alder reaction. Acetylation of the phenol, bis epoxidation, and base-catalyzed hydrolysis and cyclization afforded tetracycle 19 with the bisabosqual skeleton, but the wrong stereochemistry at the tertiary alcohol. Selective dehydration of the tertiary alcohol to form
Synthesis of the tetracyclic core of the bisabosquals
作者:Barry B. Snider、Mercedes Lobera
DOI:10.1016/j.tetlet.2004.05.005
日期:2004.6
Epoxidation of 9b afforded tetracycle 13 with the wrong stereochemistry at the tertiaryalcohol. Selective elimination of the tertiaryalcohol to give the exocyclic methylene compound, alkene cleavage to form the ketone with OsO4 and NaIO4, and addition of MeMgBr to the ketone from the least hindered face gave tertiaryalcohol 16 with the tetracyclic core of bisabosqual A (1).
New protocol for allylic substitution with aryl and alkenyl copper reagents derived from organolithiums
作者:Yohei Kiyotsuka、Yuichi Kobayashi
DOI:10.1016/j.tetlet.2008.10.002
日期:2008.12
Substitution of allylic picolinoates with copper reagentsderivedfrom sp2-carbon-lithiums and CuBr·Me2S was established to furnish anti SN2′ products with almost perfect regioselectivity and chirality transfer. The preparations of organolithiums such as lithium–halogen exchange and ortho lithiation were coupled to the substitution to install various sp2-carbon groups, which include Ph, 2,6-Me2C6H3
建立了由sp 2-碳锂和CuBr·Me 2 S衍生的铜试剂取代烯丙基吡啶啉酸酯,以提供具有几乎完美的区域选择性和手性转移的抗S N 2'产物。将有机锂的制备方法(例如锂-卤素交换和邻位锂化)与取代反应相结合,以安装各种sp 2-碳基团,其中包括Ph,2,6-Me 2 C 6 H 3,4 -Me-2,6- (MOMO)C 6 H 2,以及顺式和反式1-庚烯基。