Highly stereoselective ylide aziridination of N-sulfonylimines with sulfonium propargylides:: A simple way to synthesize scalemic acetylenylaziridines
Highly stereoselective ylide aziridination of N-sulfonylimines with sulfonium propargylides:: A simple way to synthesize scalemic acetylenylaziridines
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DOI：
10.1021/jo9800964
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发表时间：
1998-06-26
影响因子：
3.6
通讯作者：
Lin, L
中科院分区：
文献类型：
--
作者：
Li, AH;Zhou, YG;Lin, L
在相转移或低温条件下，由二苯硫盐2生成的叶立德很容易与N-磺酰亚胺1反应，以极高的产率得到乙酰基氮杂环丙烷，但顺式/反式选择性较低。当以n-BuLi为碱在低温下生成叶立德时，得到的产物3具有完整的硅基保护基团。以Cs2CO3为碱，二甲基硫盐6、21和22表现出比二苯硫盐2更好的顺反选择性(>；98：2)。上述用樟脑衍生的硫盐12-14和20进行的不对称氮杂环化反应得到的手性氮杂环丙烷的ee值高达85%。(2R，3S)-(-)-3和(2S，3R)-(+)-3可分别从12/20或13/14制备。碲盐7产生的叶立德在室温下不能与亚胺La反应，但在低温下反应成功。在这两种条件下，8-砷叶立德不能与N-磺酰亚胺反应。
Under phase-transfer or low-temperature conditions, the ylide generated from diphenylsulfonium salt 2 readily reacts with N-sulfonylimines 1 to give acetylenylaziridines in excellent yields, but low to moderate cis/trans selectivity. When using n-BuLi as the base to generate the ylide at low termperature, product 3 with an intact silyl protecting group is obtained. t-BuOK, however, leads to desilylation product 4. With Cs2CO3 as the base, dimethylsulfonium salts 6, 21, and 22 show much better cis/trans selectivity (>98:2) than diphenylsulfonium salt 2. The asymmetric version of the above aziridination reaction using camphor-derived sulfonium salts 12-14 and 20 gives chiral aziridines with ee values up to 85%. Both (2R,3S)-(-)-3 and (2S,3R)-(+)-3 can be prepared from 12/20 or 13/14, respectively. Ylides produced from telluronium salt 7 failed to react with imine la at room temperature, but the reaction succeeded at low temperature. Arsonium ylides from 8 cannot react with N-sulfonylimines under both sets of conditions.