Assembly of (2×C2+C`2)×n Molecular Complexity Using a Sequence of Pt‑ and Pd-Catalyzed Transformations with Calcium Carbide
Constructing 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, highenergy 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.
Reference: Eur. J. Org. Chem., 2023, e202301012.
