Substrate-Controlled Regio- and Stereoselective Synthesis of Boron-Substituted 1,4-Dienes via Copper-Catalyzed Boryl–Allylation of Alkynes with Allyl Phosphates and Bis(pinacolato)diboron
作者:Huai-Yu Bin、Xiao Wei、Jing Zi、Ya-Jie Zuo、Tian-Chi Wang、Chong-Min Zhong
DOI:10.1021/acscatal.5b01441
日期:2015.11.6
versatile building blocks for the synthesis of 1,4-dienes (skipped alkenes), a common motif in bioactive natural products, because of their utility in the Suzuki–Miyaura coupling reaction and conjugate additions. A method for the synthesis of boron-substituted 1,4-dienes by means of copper-catalyzed boryl–allylation of alkynes with allyl phosphate and bis(pinacolato)diboron has been developed. The regioselectivity
硼取代的1,4-二烯是用于合成1,4-二烯(跳过的烯烃)的通用结构单元,这是生物活性天然产物中的常见基序,因为它们可用于铃木-宫浦偶联反应和偶联物的添加。已经开发了一种通过炔烃与磷酸烯丙酯和双(频哪醇)二硼烷的铜催化的硼基-烯丙基化反应来合成硼取代的1,4-二烯的方法。关于炔烃和磷酸烯丙酯的区域选择性取决于炔烃和磷酸烯丙酯的结构。对于带有至少一个芳基取代基的炔烃,向炔烃中添加硼铜主要生成β-硼基-α-芳基-α-烯基铜物种,其随后与仲烯丙基磷酸酯反应生成γ-(4 E)-选择性硼取代的1,4-二烯,并与伯烯丙基磷酸酯一起提供α-选择性硼取代的1,4-二烯。另一方面,由芳基烷基乙炔作为次要中间体形成的α-硼基-α-芳基-β-烯基铜物种和由二烷基乙炔形成的β-硼基烯基铜物种对仲烯丙基磷酸酯的区域选择性较差,并产生α-和γ-选择性硼取代的1,4-二烯的混合物。但是,它们与伯烯丙基磷酸酯的反应具有很高