Reactivity of (3-chloro-2-methylenecycloalkyl)palladium Chloride Dimers: Addition of Stabilized Carbon Nucleophiles and Application to Cyclopentannulation and Cyclohexannulation
American Chemical Society
The Journal of Organic Chemistry
The titie compounds react as either “trimethylenemethane dication” synthons or “isoprenyl monocation" synthons with stabilized carbon nucleophiles in the presence of phosphine ligands. This reactivity is dependent on size of the carbocyclic ring, substituents on the ring, the amount and nature of the nucleophile, and the nature of the phosphine ligand. The product (4a) from alkylation of 2 equiv of malonate anion with (3-chloro-2- methylenecycloheptyl) palladium chloride dimer (2a) was cyclized via oxidative coupling to afford the octahydroazulene skeleton. The cyclodialkylation of 1 equiv of the dianion of dimethyl 3-ketoglutarate with 2a, followed by saponification and decarboxylation, afforded 9-ketobicyclo[5.4.0]undec-l-ene.