An effective approach to access dyadic 1,3-oxazinan-2-ones 8a-8c and 4,4a,5,6-tetrahydro-[1,3]oxazino[3,4-a]quinolin-1(3H)-ones 8d-8h was developed through Sc(OTf)3-catalyzed intramolecular cyclization from tert-butoxycarbonyl to acyliminium ion 7a-7j. A variety of substituted N,O-acetals, with different ring size, proved to be suitable substrates for this transformation, and a series of (4aS,6S,7
Abstract A palladium-catalyzedasymmetric Heck–Matsuda reaction of N-Boc-1,4-dihydroquinolines and aryl diazonium tetrafluoroborates is realized in moderate to high yields and with high enantioselectivities. The method provides an efficient route to access optically active 2-arylhydroquinolines. A palladium-catalyzedasymmetric Heck–Matsuda reaction of N-Boc-1,4-dihydroquinolines and aryl diazonium
抽象的 N -Boc-1,4-二氢喹啉和芳基重氮四氟硼酸酯的钯催化不对称Heck-Matsuda反应以中等至高收率和高对映选择性实现。该方法提供了访问光学活性的2-芳基氢喹啉的有效途径。 N -Boc-1,4-二氢喹啉和芳基重氮四氟硼酸酯的钯催化不对称Heck-Matsuda反应以中等至高收率和高对映选择性实现。该方法提供了访问光学活性的2-芳基氢喹啉的有效途径。
Synthesis of 8-chloro-benzo[ c ]quinolizin-3-ones as potent and selective inhibitors of human steroid 5α-reductase 1
作者:Antonio Guarna、Ernesto G. Occhiato、Dina Scarpi、Chiara Zorn、Giovanna Danza、Alessandra Comerci、Rosa Mancina、Mario Serio
DOI:10.1016/s0960-894x(99)00698-8
日期:2000.2
The synthesis of a series of differently substituted 8-chloro-benzo[c]quinolizin-3-ones, as potent and selective human steroid 5 alpha-reductase type 1 inhibitors, has been accomplished by a four-step procedure based on the TiCl4-promoted tandem Mannich-Michael cyclization of 2-silyloxy-1,3-butadienes with N-t-Boc iminium ions from quinolin-2-ones. The presence on the benzo[c]quinolizinone nucleus of a methyl group and a double bond at positions 6 and 4-4a, respectively, as in compound Id, gave rise to one of the most potent non-steroidal 5 alpha R-1 inhibitors reported so far (IC50 = 14 nM). (C) 2000 Elsevier Science Ltd. All rights reserved.