Synthesis of (m-carboran-9-yl)ferrocene and (m-carboran-9-yl)cymantrene

Cross-coupling reactions of 9-iodo-m-carborane with ferrocenylzinc chloride or cymantrenylzinc chloride catalyzed by (Ph₃P)₂PdCl₂ result in the formation of (m-carbo ran-9-yl)ferrocene and (m-carboran-9-yl)cymantrene, respectively. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 542–543, March, 1998.     

Crystal and molecular structures of (9-methylfluoren-9-yl)trimethyltin and (fluoren-9-yl)trimethyltin

Conclusions An increase in the length of the Sn-C (fluorene) bond is not observed in crystals of 9-fluorenyl derivatives of tin, and the variation in the lengths of the Sn-Me bonds is similar to that found in other types of organotin compounds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2054–2057, September, 1980.     

First chemoenzymatic synthesis of (R)- and (S)-1-(9H-fluoren-9-yl)ethanol

A simple chemoenzymatic synthesis of 1-(9H-fluoren-9-yl)ethanol stereoisomers is described. The enantiomers were resolved by a kinetically controlled transesterification with vinyl acetate in the presence of commercially available lipases. High-throughput screening and subsequent exhaustive investigation of the utility of the lipases in a stereoselective process of introducing chirality have been carried out. Lipase A from Candida antarctica as a cross-linked aggregate (CAL-A-CLEA) was the most efficient enzyme for the resolution of the title compound providing (S)-1-(9H-fluoren-9-yl)ethanol and its (R)-acetate in enantiopure form (>99% ee). Under mild reaction conditions, excellent enantioselectivity (E = 407), and good isolated yields of the products were obtained.