Total syntheses of a set of naturally occurring 3-oxygenated carbazole alkaloids - 6-chlorohyellazole, carazostatin, carbazomycins A and B - are described. The key-strategy underlines a highly chemo- and regioselective rhodium-catalyzed [2+2+2] cyclotrimerization between appropriately tailored yne-ynamides and 1-methoxypropyne that is stirred by the interplay of stereoelectronic and steric effects allowing the introduction of four ring substituents of the natural carbazoles within a single step and making the overall syntheses short and efficient.


中文翻译：

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铑催化的[2 + 2 + 2]环丙交酯与亚酰胺的合成：3-氧合咔唑生物碱的简明全合成的关键策略

描述了一组天然存在的3-氧化咔唑生物碱的总合成-6-氯羟唑，咔唑他汀，咔唑霉素A和B-。关键策略强调了在适当定制的炔酰胺和1-甲氧基丙炔之间的高度化学和区域选择性的铑催化的[2 + 2 + 2]环三聚，该立体三聚体通过立体电子和空间效应的相互作用而被搅拌，从而允许引入四个环取代基一步即可完成天然咔唑的制备，使整个合成过程简短高效。