A detailed study of the dialkylation of dianions derived from dihydroisoindigo 1 with enantiopure ditriflate 2 is reported. The LHMDS-mediated process has been optimized to give C(2)-symmetric product 3 with high selectivity (C(2) selectivity 3:5 = 100:1; C(2):C(1) selectivity = 8:1). Stereoselection in the C(2) manifold is determined in both the bimolecular and intramolecular alkylation steps.
报道了用对映体纯的
三氟甲磺酸酯2对衍生自二氢
异靛蓝1的二价阴离子进行二烷基化的详细研究。L
HMDS介导的过程已得到优化,以提供具有高选择性的C(2)对称产物3(C(2)选择性3:5 = 100:1; C(2):C(1)选择性= 8:1) 。在双分子和分子内烷基化步骤中确定C(2)歧管中的立体选择。