The first general preparative access to compounds of the 2,3-diethynyl-1,3-butadiene (DEBD) class is reported. The synthesis involves a one-pot, twofold Sonogashira-type, Pd0 -catalyzed coupling of two terminal alkynes and a carbonate derivative of a 2-butyne-1,4-diol. The synthesis is broad in scope and members of this structural family are kinetically stable enough to be handled using standard laboratory techniques at ambient temperature. They decompose primarily through heat-promoted cyclodimerizations, which are impeded by alkyl substitution and accelerated by aryl or alkenyl substitution. An iterative sequence of these unprecedented Sonogashira-type couplings generates a new type of expanded dendralene. A suitably substituted DEBD carrying two terminal alkyne groups undergoes Glaser-Eglinton cyclo-oligomerization to produce a new class of expanded radialenes, which are chiral due to restricted rotation about their 1,3-butadiene units. The structural features giving rise to atropisomerism in these compounds are distinct from those reported previously.

中文翻译：

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2,3-二乙炔基-1,3-丁二烯的合成与性能。

据报道，首次普遍制备了2,3-二乙炔基-1,3-丁二烯（DEBD）类化合物。该合成涉及两个末端炔烃和2-丁炔-1,4-二醇的碳酸酯衍生物的一锅，双重Sonogashira型，Pd0催化的偶联。合成的范围很广，该结构族的成员在动力学上足够稳定，可以在环境温度下使用标准实验室技术进行处理。它们主要通过热促进的环二聚作用而分解，其被烷基取代所阻碍并被芳基或烯基取代所加速。这些史无前例的Sonogashira型偶联的重复序列生成了新型的扩展树枝状烯。带有两个末端炔基的适当取代的DEBD进行Glaser-Eglinton环低聚反应，生成一类新的膨胀的expanded烯，由于它们在1,3-丁二烯单元周围的受限旋转，它们是手性的。在这些化合物中引起阻转异构的结构特征与先前报道的截然不同。