• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemistry: A European journal >Highly enantioselective aldol reactions between acetaldehyde and activated acyclic ketones catalyzed by chiral primary amines
【24h】

Highly enantioselective aldol reactions between acetaldehyde and activated acyclic ketones catalyzed by chiral primary amines

机译：乙醛与手性伯胺催化的活化无环酮之间的高度对映选择性醛醇缩合反应

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Highly enantioselective cross-aldol reactions between acetaldehyde and activated acyclic ketones are reported for the first time. Various acyclic ketones, such as saturated and unsaturated keto esters, reacted with acetaldehyde in the presence of a chiral primary amine and a Br?nsted acid to afford optically enriched tertiary alcohols in good yields and with excellent enantioselectivities. Trifluoromethyl ketones were tolerable under the reaction conditions, thereby affording the trifluoromethyl carbinol in good-to-excellent yields and enantioselectivities. Structural modification of the chiral amines from the same chiral source switched the stereoselectivity of the products. The utility of aldol chemistry was demonstrated in the brief synthesis of functionally enriched δ-lactones. Theoretical calculations on the transition-state structure indicated that the protonated tertiary amine could effectively activate the carbonyl group of a keto ester to promote the addition process through hydrogen-bonding interaction and, simultaneously, provide an appropriate attacking pattern for the approach of the keto ester to the enamine, which is formed from acetaldehyde and the chiral catalyst, on a particular face, resulting in high enantioselectivity.
机译：首次报道了乙醛与活化的无环酮之间的高度对映选择性的交叉羟醛反应。在手性伯胺和布朗斯台德酸的存在下，各种无环酮（例如饱和和不饱和酮酯）与乙醛反应，以良好的收率和优异的对映选择性提供光学富集的叔醇。在反应条件下可耐受三氟甲基酮，从而以良好至优异的产率和对映选择性提供三氟甲基甲醇。来自相同手性来源的手性胺的结构修饰改变了产物的立体选择性。醛醇化学的实用性在功能丰富的δ-内酯的简短合成中得到了证明。过渡态结构的理论计算表明，质子化叔胺可以通过氢键相互作用有效地活化酮酸酯的羰基，促进加成过程，同时为酮酸酯的合成提供合适的攻击方式。由乙醛和手性催化剂形成的烯胺在一个特定的表面上，产生高对映选择性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号