“…When the mixture was stirred for 24 ha t 120 8C, the corresponding indanone product, 1,2,3,4,4a,9a-hexahydro-1,4-methanofluoren-9-one( 3), was obtained in 4% yield as determined by gas chromatography (GC) (entry 1). The use of electron-rich phosphine ligands, such as P(4-MeOC 6 H 4 ) 3 or JohnPhos instead of PPh 3 furnished 3 in 49 %a nd 20 % yield, respectively (entries 2a nd 3). The most effective electron-richl igand was PCy 3 ,w hich afforded 3 in 76 %y ield (entry 4).…”