An Alternative Synthesis of Cycloalkyl-Substituted CPA Catalysts and Application in Asymmetric Protonation Reactions**
An Alternative Synthesis of Cycloalkyl-Substituted CPA Catalysts and Application in Asymmetric Protonation Reactions**
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DOI：
10.1002/ejoc.202100980
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发表时间：
2021-09
影响因子：
2.8
通讯作者：
Liam A. McLean;A. Watson
中科院分区：
文献类型：
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作者：
Liam A. McLean;A. Watson
报道了环烷基取代的CPA催化剂的替代合成。Negishi偶联提供了必要的1，3，5-三（环烷基）苯的改进的产率和纯度。在使用商业有机锌试剂的限制已被确定，并详细说明了这些试剂的制备的一个强大的程序。同样，还提供了关键Kumada耦合的稳健程序。该路线通过制备三种不同的三（环烷基）芳基取代的CPA来证明，并显示了这些催化剂在不对称质子化反应中的效用。
An alternative synthesis of cycloalkyl‐substituted CPA catalysts is reported. A Negishi coupling offers improved yields and purity of the necessary 1,3,5‐tri(cycloalkyl)benzenes. Limitations in the use of commercial organozinc reagents have been identified and a robust procedure for the preparation of these reagents is detailed. Similarly, a robust procedure for the key Kumada coupling is also provided. The route is demonstrated by preparation of three different tri(cycloalkyl)aryl‐substituted CPAs and the utility of these catalysts in asymmetric protonation reactions is shown.