异硫脲催化的酯的对映选择性α-烷基化反应：通过 1,6-共轭加成到醌甲基化物。

EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK.

Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.

Molecules. 2021 Oct 20;26(21):6333. doi: 10.3390/molecules26216333.

The isothiourea-catalyzed enantioselective 1,6-conjugate addition of -nitrophenyl esters to 2,6-disubstituted -quinone methides is reported. -Nitrophenoxide, generated in situ from initial -acylation of the isothiourea by the -nitrophenyl ester, is proposed to facilitate catalyst turnover in this transformation. A range of -nitrophenyl ester products can be isolated, or derivatized in situ by addition of benzylamine to give amides at up to 99% yield. Although low diastereocontrol is observed, the diastereoisomeric ester products are separable and formed with high enantiocontrol (up to 94:6 er).

报道了异硫脲催化的对硝基苯基酯与 2,6-二取代-醌甲亚胺的对映选择性 1,6-共轭加成反应。据推测，-硝基苯氧负离子是由异硫脲初始酰化对硝基苯基酯原位生成的，它促进了这一转化中的催化剂循环。一系列对硝基苯酯产物可以被分离出来，或者通过加入苄胺原位衍生化，以高达 99%的收率得到酰胺。尽管观察到低的非对映选择性，但非对映异构体酯产物是可分离的，并且具有高的对映选择性（高达 94:6 er）。