Palladium-catalyzed syntheses of naturally-occurring acetylenic thiophens and related compounds
作者:Renzo Rossi、Adriano Carpita、Alessandro Lezzi
DOI:10.1016/s0040-4020(01)96897-8
日期:1984.1
BnEt3N+Cl- as phase transfer agent and 2.5NaqNaOH as base, has been also employed to prepare a large number of heterocyclic acetylene derivatives including some naturally-occurring compounds. The experimetal conditions of Method B allow also the direct production of heterocyclic acetylene derivatives (1) starting from 1-alkynyltrimethylsilanes (5) and organic halides (2).
5-(3-丁烯-1-炔基)-2,2'-噻吩基(1a)是首先从万寿菊根中分离的天然产物,具有杀线虫和光诱导的杀真菌活性,以及2-苯基-5-(3-丁烯-1-炔基)噻吩(1b)已使用两种不同方法合成。第一种方法(方法A)涉及钯催化的乙烯基溴与衍生自5-ethynyl-2,2'-bithienyl(6a)和2-ethynyl-5-phenylthiophen(6b)的Grignard试剂的交叉偶联。第二种方法(方法B)在催化量为(PPh 3)4的情况下分别利用溴化乙烯与6a和6b的偶联反应。Pd和CuI。这样的反应,这是采用BNET相转移条件下进行3 Ñ +氯-作为相转移剂和2.5NaqNaOH作为碱,也已用来制备大量的杂环乙炔衍生物,包括一些天然存在的化合物。方法B的实验金属条件还允许从1-炔基三甲基硅烷(5)和有机卤化物(2)开始直接生产杂环乙炔衍生物(1)。