Enantioconvergent intramolecular coupling of α-(2-bromobenzoylamino)benzylboronic esters was achieved using a copper catalyst having helically chiral macromolecular bipyridyl ligand, PQXbpy. Racemic α-(2-bromobenzoylamino)benzylboronic esters were converted into (R)-configured 3-arylisoindolinones with high enantiopurity using right-handed helical PQXbpy as a chiral ligand in a toluene/CHCl3 mixed solvent. When enantiopure (R)- and (S)-configured boronates were separately reacted under the same reaction conditions, both afforded (R)-configured products through formal stereoinvertive and stereoretentive processes, respectively. From these results, a mechanism involving deracemization of organocopper intermediates in the presence of PQXbpy is assumed. PQXbpy switched its helical sense to left-handed when a toluene/1,1,2-trichloroethane mixed solvent was used, resulting in the formation of the corresponding (S)-products from the racemic starting material.

中文翻译：

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使用连接到螺旋手性大分子支架的 C1-对称 2,2'-联吡啶基配体在 α-氨基烷基硼酸酯的硼键合 C(sp3) 原子处对映收敛的 Cu 催化的分子内 C-C 偶联

使用具有螺旋手性大分子联吡啶配体 PQXbpy 的铜催化剂实现了 α-（2-溴苯甲酰氨基）苄基硼酸酯的对映收敛分子内偶联。在甲苯/三氯甲烷混合溶剂中，使用右手螺旋 PQXbpy 作为手性配体，将外消旋 α-(2-溴苯甲酰氨基) 苄基硼酸酯转化为 (R)-构型的具有高对映纯度的 3-芳基异吲哚啉酮。当对映体纯（R）-和（S）-构型的硼酸酯在相同的反应条件下分别反应时，两者分别通过形式立体转化和立体保留过程提供（R）-构型的产物。根据这些结果，假设了一种涉及在 PQXbpy 存在下有机铜中间体去外消旋的机制。当甲苯/1,1 时，PQXbpy 将其螺旋方向切换为左旋，