The 2,6-dimercaptoazulene motif: efficient synthesis and completely regioselective metallation of its 6-mercapto terminus
作者:Kolbe J. Scheetz、Andrew D. Spaeth、Alexander S. Vorushilov、Douglas R. Powell、Victor W. Day、Mikhail V. Barybin
DOI:10.1039/c3sc51773j
日期:——
2,6-Dimercapto-1,3-diethoxycarbonylazulene, a rare example of an unsymmetrical dimercaptoarene, was efficiently synthesized via two routes from common azulenic precursors. The SH-termini of this linear nonbenzenoid dimercaptan exhibit markedly different acidities, which permitted exclusively regioselective metallation of its 6-SH end with the [PPh3PAuI] fragment to afford the only mononuclear adduct (10) of a dimercaptoarene known to date. Subsequent metallation of the 2-SH terminus of 10 with another equivalent of [PPh3PAuI] gave the corresponding dinuclear AuI complex featuring the 2,6-azulenedithiolate linker. The complex constitutes a unique unsymmetrical platform for probing the exchange of gold-bound thiolates within a single compound.
2,6-Dimercapto-1,3-diethoxycarbonylazulene 是一种罕见的非对称二巯基烯,通过两种途径从常见的偶氮前体中高效合成。这种线性非苯类二巯基化合物的 SH 端表现出明显不同的酸性,这使得其 6-SH 端与[PPh3PAuI]片段发生完全区域选择性的金属化反应,从而得到了迄今已知的唯一一种二巯基炔的单核加合物 (10)。随后,10 的 2-SH 末端与另一个等量的 [PPh3PAuI] 发生金属化反应,得到了相应的具有 2,6-偶氮二硫酸盐连接体的双核 AuI 复合物。该复合物构成了一个独特的非对称平台,可用于探测单个化合物中与金结合的硫醇盐的交换。