A phosphine‐free nickel(II)‐catalyzed method for the C(2)−H bond alkynylation of (benzo)thiazoles, (benz)imidazoles, and oxazoles is described. Well‐defined and air‐stable (Phen)NiCl₂ catalyst efficiently catalyzes the coupling of diverse azoles with alkynyl bromides without the use of a copper co‐catalyst, and the method tolerates synthetically important functional groups. Preliminary mechanistic studies on this Ni^II‐catalyzed alkynylation emphasize the homogeneous nature of the catalyst, and rule out a radical manifold for the reaction. The synthetic utility of this Ni‐catalyzed method is demonstrated by further functionalizing the alkynylated benzothiazoles to 3‐methyl‐2‐(alkynyl)benzo[d]thiazolium salts that are known DNA cleaving agents.

中文翻译：

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铜和无磷镍（II）催化方法联苯并噻唑和相关腈的C-H键炔化反应

描述了一种无膦的镍（II）催化方法，用于（苯并）噻唑，（苯并咪唑）和恶唑的C（2）-H键烷基化。定义明确且空气稳定的（Phen）NiCl ₂催化剂可有效催化多种唑类与炔基溴的偶联，而无需使用铜助催化剂，该方法可耐受合成中重要的官能团。对该Ni ^II催化的炔基化反应的初步机理研究强调了催化剂的均相性质，并排除了反应的自由基。通过将炔基化的苯并噻唑进一步官能化为已知的DNA裂解剂3-甲基-2-（炔基）苯并[ d ]噻唑鎓盐，可以证明这种Ni催化方法的合成实用性。