An approach to access 1-substituted isoquinolones has been developed through the addition–cyclization of imines with Grignard reagents in the presence of 2,2′-dipyridyl. A number of substituted aromatic magnesium reagents were amenable to this process, and the desired products were obtained with excellent yields and outstanding diastereoselectivities (dr > 99:1). The utility of this convenient approach is demonstrated by the formal synthesis of (S)-cryptostyline II. Moreover, N-methylmorpholine (NMM) was found to be an effective additive for the formation of 3-substituted isoindolin-1-ones using one-pot addition–cyclization–deprotection of imine with Grignard reagents.

中文翻译：

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加成环化法制备手性1-取代异喹诺酮和3-取代异吲哚啉-1-酮

通过在2，2'-联吡啶存在下，用格氏试剂对亚胺进行加成环化反应，已经开发了一种获得1-取代异喹诺酮的方法。许多取代的芳族镁试剂都适用于此过程，并以优异的收率和出色的非对映选择性（dr > 99：1）获得了所需的产物。这种便利方法的实用性通过（S）-cryptostyline II的形式合成得到证明。此外，使用格氏试剂一锅加成-环化-亚胺脱保护，发现N-甲基吗啉（NMM）是形成3取代异吲哚啉-1-酮的有效添加剂。