Assembly of (2×C2+C’2)×n Molecular Complexity Using a Sequence of Pt‐ and Pd‐Catalyzed Transformations with Calcium Carbide

Abstract

AbstractConstructing molecular complexity from simple precursors stands as a cornerstone in contemporary organic synthesis. Systems harnessing easily accessible starting materials, which offer control over stereochemistry and support a modular assembly approach, are particularly in demand. In this research, we utilized calcium carbide, presenting a sustainable pathway to generate acetylene gas – a fundamental C2 building block. We performed a Pt‐facilitated linkage of two C2‐units sourced from two calcium carbide molecules to craft a conjugated C4 core with exceptional stereoselectivity. As a benchmark, we selected the synthesis of (E,E)‐1,4‐diiodobuta‐1,3‐diene, executing it in a two‐chamber reactor. Compartmentalization of the reactions across these chambers resulted in the desired product in 85% yield. Furthermore, high‐energy polymeric substances were derived by marrying the molecular intricacy between (E,E)‐1,4‐diiodobuta‐1,3‐diene and calcium carbide, underpinning a unique C4+C2 assembly blueprint. The structure and morphology of the polymeric material were characterized by IR and NMR spectroscopy, scanning electron microscopy, and energy dispersive X‐ray spectroscopy. Overall, two complementary 2×C2‐to‐C4 and (2×C2+C’2)×n assembly schemes were developed using Pt and Pd catalysis.