Complementary asymmetric routes to fused tricyclic (R)-2,3,4,4a,5,6-hexahydro-1H-pyrazino[1,2-a]quinolines and (R)-1,2,3,4,5,5a,6,7-octahydro-[1,4]diazepino[1,2-a]quinolines
作者:Thomas O. Schrader、Michelle Kasem、Qi Sun、Chunrui Wu、Albert Ren、Graeme Semple
DOI:10.1016/j.tetlet.2016.09.025
日期:2016.10
7-octahydro-[1,4]diazepino[1,2-a]quinolines, low MW tricyclic organic scaffolds with a high degree of molecular complexity, are described. The key transformation in route 1 is the lateral lithiation of an N-Boc-o-toluidine and dianion trap with (S)-tert-butyldimethyl(oxiran-2-ylmethoxy)silane. An intramolecular SN2 cyclization then forms the optically pure tetrahydroquinoline core. Route 2 involves the
(R)-2,3,4,4a,5,6-hexahydro-1 H -pyrazino [1,2- a ]喹啉和(R)-1,2,3,4,5的两种不同的对映选择性方法描述了5a,6,7-八氢-[1,4]二氮杂[1,2- a ]喹啉,其具有高度分子复杂性的低MW三环有机支架。路线1中的关键转变是N- Boc-邻甲苯胺和二价离子阱与(S)-叔丁基二甲基(环氧乙烷-2-基甲氧基)硅烷的侧向锂化反应。分子内小号Ñ 2环化然后形成光学纯的四氢喹啉核。路线2涉及(R)-2-(4-苄基-1-(Boc)哌嗪-2-基)乙醛或(R)-2-(4-苄基-1-(Boc)-1,4-二氮杂-2-基)乙醛与芳基锂和随后的分子内S N Ar反应形成三环。两种合成途径对于制备和鉴定靶向中枢神经系统(CNS)中表达的GPCR的配体都是有价值的。