The First Examples of a <i>Meta</i>-Benzannulation from the Reaction of Fischer Carbene Complexes with Alkynes
作者:Huan Wang、Jie Huang、William D. Wulff、Arnold L. Rheingold
DOI:10.1021/ja035428n
日期:2003.7.1
intramolecular benzannulations of carbene complexes with alkynes are examined where the alkyne is tethered to the alpha-carbon of the vinyl carbene complex. These reactions are sensitive to the length of the tether and to the nature of the solvent. With a tether length of 16 methylenes, the reaction occurs in the same fashion as the intermolecular reactions to give a p-cyclophane. With intermediate
Unexpected Regiochemistry in the Benzannulation Reaction of Fischer Carbene Complexes in the Synthesis of Cyclophanes
作者:Huan Wang、William D. Wulff、Arnold L. Rheingold
DOI:10.1021/ja0020106
日期:2000.10.1
complex 6 would undergo an intramolecular benzannulation with incorporation of the tethered terminal alkyne to givem-cyclophane8b in 58% yield.4,5 This method gives synthetically useful yields of m-cyclophanes and has been examined for tether lengths up to 17 methylenes with no dropoff in yield (60% yield forn ) 17). Them-cyclophane8b was expected from this reaction on the basis of the regiochemistry observed