Efficient synthetic strategies for furnishing α-carbolines have been developed by integrating various Pd-catalyzed reactions. The methods involve 1) regioselective 5- or 6- halogenation of α-carbolines which were synthesized through intramolecular Pd-catalyzed direct C-H arylation, and subsequent Pd-catalyzed cross coupling, 2) 8-triflation of α-carbolines constructed by Pd-catalyzed cyclization, followed by Pd-catalyzed cross-coupling reaction, 3) Pd-catalyzed cyclization to tetrahydro-α-carbolines and subsequent Suzuki reaction via the corresponding α-carboline 5-triflates.

中文翻译：

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集成Pd催化的交叉偶联策略，用于制备α-咔啉

通过整合各种Pd催化的反应，已经开发出用于合成α-咔啉的有效合成策略。该方法包括：1）通过分子内Pd催化的直接CH芳基化反应合成的α-咔啉的区域选择性5-或6-卤代，然后进行Pd催化的交叉偶联； 2）通过Pd催化的α-咔啉的8-三氟甲磺酸酯化。环化，然后进行Pd催化的交叉偶联反应，3）Pd催化的环化反应生成四氢-α-咔啉，随后通过相应的α-咔啉5-三氟甲磺酸酯进行Suzuki反应。