Nickel(0)-catalyzed Coupling Reactions of Carbonyls and Alkenes with Reducing Reagents Giving Six- and Seven-membered Benzocycloalkanols

Nickel(0)-catalyzed coupling reactions of 1,6-and 1,7-enals with triethylsilane have been utilized to synthesize six- and seven-membered silyl-protected benzocycloalkanols. When triethylborane was employed as the reducing reagent, tetralol derivatives were obtained. Results of deuterium-labeling experiments suggest the formation of oxanickelacycles as a key reaction intermediate.