Desilylative elimination of the quinazolinone ring from 1-(4-oxoquinazolin-3-yl)-2-silylaziridines; preparation of an N–H aziridine in high enantiomeric excess by in situ nucleophilic addition to the derived azirine
作者:Robert S. Atkinson、Michael P. Coogan、Ian S. T. Lochrie
DOI:10.1039/a606092g
日期:——
Aziridination of vinylsilanes
PhCHCHSiR3 (R = Me, Et, Ph) with
enantiopure 3-acetoxyaminoquinazolinone 11 gives the
corresponding aziridines 12 [diastereoisomer ratio (dr)
10â¶1], 18 (dr 13â¶1) and 20 (dr 2â¶1).
Desilylative elimination of the quinazolinone from these
aziridines by caesium fluoride in the presence of cyanide gives
aziridine 14 by cyanide addition to the 3-unsubstituted azirine
13, produced in situ. Acylation of aziridine 14 with
(S)-acetoxypropionyl chloride gives
N-acylaziridine 16; the good correlation between the
diastereoisomer ratios of aziridines 12, 18 and 20 and those of
the N-acylaziridine 16 produced in each case suggests
that intermediate azirine 13 is configurationally
stable.
乙烯基硅烷的氮丙啶化
PhCHCHSiR3 (R = Me, Et, Ph) 与
对映体纯 3-乙酰氧基氨基喹唑啉酮 11 给出
相应的氮丙啶 12 [非对映异构体比例 (dr)
10-1]、18(13-1 博士)和 20(2-1 博士)。
从这些物质中脱甲硅烷基消除喹唑啉酮
在氰化物存在下与氟化铯反应生成氮丙啶
氮丙啶 14 通过氰化物加成到 3-未取代的氮丙啶上
13、原地制作。氮丙啶 14 的酰化
(S)-乙酰氧基丙酰氯得到
N-酰基氮丙啶16;之间的良好相关性
氮丙啶 12、18 和 20 的非对映异构体比例
每种情况下产生的 N-酰基氮丙啶 16 表明
中间体氮丙啶 13 在构型上是
稳定的。