An Expeditious Route to 1α,25-Dihydroxyvitamin D<sub>3</sub>and Its Analogues by an Aqueous Tandem Palladium-Catalyzed A-Ring Closure and Suzuki Coupling to the C/D Unit
作者:Pranjal Gogoi、Rita Sigüeiro、Silvina Eduardo、Antonio Mouriño
DOI:10.1002/chem.200902972
日期:2010.2.1
mild, general, and highly stereoselective Pd0‐catalyzed cascade to the triene system of the hormone 1α,25‐dihydroxyvitamin D3 and six representative analogues is reported. The intramolecular cyclization of an enol–triflate (lower fragment) followed in situ by Suzuki–Miyaura coupling with an alkenyl boronic ester (upper fragment, also efficiently prepared by Pd0‐catalyzed coupling) in equimolar amounts
每日维生素:有轻度,一般和高度立体选择性的Pd 0催化与1α,25-二羟基维生素D 3和6种代表性类似物的三烯系统级联。在质子化条件下等摩尔量的烯醇-三氟甲磺酸分子的分子内环化(下片段),然后是铃木-宫浦(Suzuki-Miyaura)与烯基硼酸酯(上片段,也可通过Pd 0催化偶联有效制备)原位合成用于生物测试的少量新维生素D类似物(请参阅计划)。