Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg im Breisgau (Germany).
Angew Chem Int Ed Engl. 2015 Dec 21;54(52):15818-22. doi: 10.1002/anie.201507623. Epub 2015 Sep 29.
A Z-selective rhodium-catalyzed hydrothiolation of 1,3-disubstituted allenes and subsequent oxidation towards the corresponding allylic sulfones is described. Using the bidentate 1,4-bis(diphenylphosphino)butane (dppb) ligand, Z/E-selectivities up to >99:1 were obtained. The highly atom-economic desymmetrization reaction tolerates functionalized aromatic and aliphatic thiols. Additionally, a variety of symmetric internal allenes, as well as unsymmetrically disubstituted substrates were well tolerated, thus resulting in high regioselectivities. Starting from chiral but racemic 1,3-disubstituted allenes a dynamic kinetic resolution (DKR) could be achieved by applying (S,S)-Me-DuPhos as the chiral ligand. The desired Z-allylic sulfones were obtained in high yields and enantioselectivities up to 96 % ee.
描述了一种 Z-选择性的铑催化 1,3-二取代丙二烯的氢硫加成反应，以及随后的氧化反应，得到相应的烯丙基砜。使用双齿配体 1,4-双（二苯基膦）丁烷（dppb），可以获得高达>99:1 的 Z/E 选择性。高度原子经济性的去对称化反应可以容忍官能化的芳香族和脂肪族硫醇。此外，各种对称的内部丙二烯以及不对称取代的底物也能很好地耐受，从而实现了高区域选择性。从手性外消旋的 1,3-二取代丙二烯出发，通过使用(S,S)-Me-DuPhos 作为手性配体，可以实现动态动力学拆分（DKR）。以高收率和高达 96%ee 的对映选择性获得了所需的 Z-烯丙基砜。
