Pd-Catalyzed Carbocyclization−Negishi Cross-Coupling Cascade: A Novel Approach to 1α,25-Dihydroxyvitamin D<sub>3</sub> and Analogues
作者:Clara Gómez-Reino、Cristian Vitale、Miguel Maestro、Antonio Mouriño
DOI:10.1021/ol052489c
日期:2005.12.1
[reaction: see text] A mild palladium-catalyzed cascade has been used for the synthesis of the hormone 1alpha,25-dihydroxyvitamin D3 (calcitriol, 1a) and its analogues 1b and 1c. This one-pot process involves two consecutive transformations at room temperature: An initial palladium-catalyzed 6-exo-cyclocarbopalladation of vinyl triflates followed by a Negishi cross-coupling reaction with an alkenyl
[反应:见正文]轻度钯催化的级联反应已用于合成1α,25-二羟基维生素D3激素(骨化三醇,1a)及其类似物1b和1c。此一锅法涉及室温下的两个连续转化:乙烯基三氟甲磺酸酯的初始钯催化的6-exo-cyclocarbopladladation,然后与烯基锌的Negishi交叉偶联反应。这种新颖的策略为制备具有治疗潜力的各种新的维生素D类似物提供了新的可能性,特别是对三烯和/或环A进行了修饰。