Ready Access to 6-Alkyl, 6-Phenyl, 5,6-Dialkyl, and 5-Alkyl-6-phenyl Substituted 1,2,3,4-Tetrahydroisoquinolines
作者:Peter Nussbaumer、Thomas Dechat
DOI:10.1007/s007060170045
日期:2001.9
Readily available bicyclic enone precursors were used in a novel strategy for the synthesis of 6-mono- and 5,6-disubstituted tetrahydroisoquinolines (alkyl and phenyl in position 6, hydrogen and methyl in position 5). After 1,2-addition of the respective organometallic reagents to the enones, the crude intermediate alcohols were subjected to a dehydratization/aromatization procedure using the in situ
易于获得的双环烯酮前体用于合成6-单-和5,6-二取代的四氢异喹啉(位置6的烷基和苯基,位置5的氢和甲基)的新型策略中。在将各种有机金属试剂1,2-添加到烯酮中之后,使用 原位 生成的三苯甲基阳离子对粗制中间体醇进行脱水/芳香化程序 。通过该程序获得的总产率在27%至86%之间。N-苄基保护的6- 叔 丁基-四氢异喹啉成功合成,而 5-甲基-6- t 发生部分脱烷基 丁基类似物。一些新的N-苄基四氢异喹啉被转化为相应的未保护的杂环。
The Fit For Purpose Development of S1P<sub>1</sub> Receptor Agonist GSK2263167 Using a Robinson Annulation and Saegusa Oxidation to Access an Advanced Phenol Intermediate
作者:Robert M. Harris、Benjamin I. Andrews、Stacy Clark、Jason W. B. Cooke、John C. S. Gray、Stephanie Q. Q. Ng
DOI:10.1021/op400162p
日期:2013.10.18
A fit for purpose approach has been adopted in order to develop a robust, scalable route to the S1P(1) receptor agonist, GSK2263167. The key steps include a Robinson ring annulation followed by a Saegusa oxidation, providing rapid access to an advanced phenol intermediate. Despite the use of stoichiometric palladium acetate for the Saegusa oxidation, near complete recovery of the palladium has been demonstrated. The remaining steps have been optimised including the removal of all chromatography. An alternative to the Saegusa oxidation is described as well as the development of a flow process to facilitate further scale-up of the amidoxime preparation using hydroxylamine at elevated temperature.