This project focuses on the design and synthesis of a new type of 1,3-diene, containing a functionalized hydrazino group at position 1, and on the exploration of its intermolecular Diels-Alder reactions with various electron deficient alkenes and heterodienophiles. In a subsequent step, cleavage of two protecting groups on one of the nitrogen atoms triggers a sequential fragmentation and a suprafacial 1,5-sigmatropic rearrangement of hydrogen with loss of a molecule of nitrogen. This thermodynamically driven process, which presumably passes through an allylic diazene intermediate, gives rise to a rearranged cyclohexene with a remote stereochemical relationship. The two-stage strategy is thus founded on the powerful Diels-Alder cycloaddition as a ring forming process and the facility of allylic diazene rearrangements. The unique chemistry of the 1-hydrazinodienes provides direct access to stereochemically complex cyclohexenes that would be difficult to construct by alternative synthesis strategies.
With this award, the Organic and Macromolecular Chemistry Program is supporting the research of Dr. Erik J. Sorensen of the Department of Chemistry at Princeton University. Since its initial description in 1928, the Diels-Alder reaction has evolved into one of the most important structure building processes in the field of chemical synthesis. The novel reactants targeted by Professor Sorensen and his students are easily synthesized from simple, commercially available compounds, and they enable short syntheses of complex ring systems that would be challenging to construct by alternative strategies. These studies are expected to have a strong impact on the field of chemical synthesis, providing chemists with an alternative way of perceiving and utilizing the Diels-Alder reaction in the planning and execution of organic syntheses. In addition, this reaction chemistry will potentially yield structurally diverse compounds for use in complex chemical synthesis and medicinal chemistry.
