Charge‐activated TADDOLs: Recyclable organocatalysts for asymmetric (hetero‐)Diels–Alder reactions
Charge‐activated TADDOLs: Recyclable organocatalysts for asymmetric (hetero‐)Diels–Alder reactions
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电荷活化 TADDOL：用于不对称（杂）狄尔斯·阿尔德反应的可回收有机催化剂
DOI：
10.1002/poc.4355
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发表时间：
2022
影响因子：
1.8
通讯作者：
Kass, Steven R.
中科院分区：
文献类型：
--
作者：
Riegel, George F.;Takashige, Keiji;Lovstedt, Alex;Kass, Steven R.
合成了几种含电荷的TADDOL盐，并用作不对称Diels-Alder和杂Diels-Alder反应中的有机催化剂。发现它们的催化活性超过不带电的类似物，同时保持或改善对映选择性。TADDOL盐的增强的活性使得它们能够分别在40°C下1，3-环己二烯与甲基乙烯基酮和室温下2-苯氧基-1，3-丁二烯与乙醛酸乙酯的Diels-Alder和杂Diels-Alder反应中充当假定的氢键供体催化剂。考虑到这些电荷活化催化剂的离子性质，还证明可以回收和再利用TADDOL而无需色谱或重结晶。
Several charge‐containing TADDOL salts were synthesized and used as organocatalysts in asymmetric Diels–Alder and hetero‐Diels–Alder reactions. Their catalytic activity was found to exceed that of a noncharged analog while maintaining or improving upon the enantioselectivity. The enhanced activities of the TADDOL salts enabled them to act as presumed hydrogen bond donor catalysts in the Diels–Alder and hetero‐Diels–Alder reactions of 1,3‐cyclohexadiene with methyl vinyl ketone at 40°C and 2‐phenoxy‐1,3‐butadiene with ethyl glyoxylate at room temperature, respectively. Given the ionic nature of these charge‐activated catalysts, it also proved possible to recycle and reuse the TADDOL without chromatography or the need for a recrystallization.