CpCo-Mediated Reactions of Cyclopropenones: Access to CpCo-Capped Benzoquinone Complexes
作者:Andreea Schuster-Haberhauer、Rolf Gleiter、Olivia Körner、Adriane Leskovar、Daniel B. Werz、Felix R. Fischer、Frank Rominger
DOI:10.1021/om701115w
日期:2008.4.1
The reaction of di(n-propyl)cyclopropenone (7), di(n-butyl)cyclopropenone (16), and bicyclo[12.1.0]pentadeca-1(14)-en-7-yn-15-one (21) with CpCo(CO)(2) and CpCo(cod) yielded CpCo-complexed benzoquinone and cyclopentadienone derivatives. When 16 was reacted with CPCO(CO)(2) and a 10-fold surplus of 4-octyne, a mixture of CpCo-capped benzoquinone 25 and cyclopentadienone 26 was isolated. The reaction of cyclopropenone 16 containing a C-13-labeled CO group with CPCO(CO)(2) yielded a CpCo-capped tetrakis(n-butyl)-p-benzoquinone with one C-13 nucleus per molecule as the main product. The mechanism of the formation of p-benzoquinone is discussed on the basis of the results of trapping and labeling experiments.
Doubly Bridged Biscyclopropenones, a New Family of Phanes
The first representatives, 10-12, of the new species of double-decked cyclopropenonophanes were synthesized by cycloaddition reactions of dichlorocarbene to alkynylenecyclopropenonophanes 7-9 followed by hydrolysis as well as in an alternative route involving hydride abstraction from dichlorotricycloalkadienes 16 and 17 to dichlorocyclopropenyliophanes and in situ hydrolysis of the latter. The X-ray analysis of [3.3]cyclopropenonophane 10 reveals a considerable tetragonalization of the bridgehead carbon atoms, indicating a significant deformation of the cyclopropenone moieties in the phane corset, According to ab initio calculations, the it orbitals of the cyclopropenones display transannular interactions of nearly the same scale as found in 7.