Publications
2025
The Diels–Alder reaction of benzenes remains a significant synthetic challenge, owing to their highly stabilized aromatic cores. In this work, the dearomatization agent {WTp(NO)(PMe3)} is used to promote Diels–Alder reactions of dihapto-coordinated (η2) benzenes with alkynes. The resulting η2-barrelene complexes can be oxidized to liberate intact barrelenes. Alternatively, mild pyrolysis leads to the extraction of the corresponding tungsten-acetylene complex and concomitant formation of new arenes possessing substituents originating from the acetylene dienophiles.
We report the synthesis of Rh–Sb complexes using high valent Sb ligands, Q3SbCl2 (1, Q = 8-quinolinyl) and Q3SbF2 (2), from the low valent Rh precursor [(CO)2Rh(μ-Cl)]2 to afford the complexes [(κ4-Q3SbCl)Rh(CO)Cl][(CO)2RhCl2] (3) and (κ4-Q3SbF2)Rh(CO)Cl (4), respectively. The reaction of 1 with [(CO)2Rh(μ-Cl)]2 results in the transfer of chloride from Sb to Rh to give the ion pair 3 with a Rh–Sb bond for the cation that, according to computational analysis, has some covalent character. Replacing Sb–Cl with Sb–F bonds (i.e., compound 2) inhibited halide transfer and allowed formation of 4 with a Rh→Sb interaction that has more Z-type character than the Rh–Sb bond for complex 3. Molecular orbital and localized orbital bonding analyses are consistent with the proposed Rh→Sb interaction of 4 being more Z-type in character.