Johannsen Tim, Golz Christopher, Alcarazo Manuel
Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammanstr. 2, Göttingen, Germany.
Angew Chem Int Ed Engl. 2020 Dec 7;59(50):22779-22784. doi: 10.1002/anie.202009303. Epub 2020 Oct 8.
A series of structurally differentiated α-cationic phospholes containing cyclopropenium, imidazolium, and iminium substituents has been synthesized by reaction of chlorophosphole 1 with the corresponding stable carbenes. Evaluation of the donor properties of these compounds reveals that their strong π-acceptor character is heavily influenced by the nature of the cationic group. The coordination chemistry of these newly prepared ligands towards Au centers is also described and their unique electronic properties exploited in catalysis. Interestingly, α-cationic phosphole containing catalysts were not only able to accelerate model cycloisomerization reactions, but also to efficiently discriminate between concurrent reaction pathways, avoiding the formation of undesired product mixtures.
通过氯代磷烯1与相应的稳定卡宾反应，合成了一系列含有环丙烯鎓、咪唑鎓和亚胺鎓取代基的结构不同的α-阳离子磷烯。对这些化合物供体性质的评估表明，它们强烈的π-受体特性受到阳离子基团性质的严重影响。还描述了这些新制备的配体与金中心的配位化学，并在催化中利用了它们独特的电子性质。有趣的是，含α-阳离子磷烯的催化剂不仅能够加速模型环异构化反应，还能够有效地区分同时存在的反应途径，避免形成不需要的产物混合物。
