Synthesis And Resolution Of 1,1'-Spirobiindane-7,7'-diol And Its 4,4'-Derivatives And Their Applications In Asymmetric Catalytic Alkylation

For the first time, enantiomers of C2-symmetric 1,1 -spirobiindane-7,7'-diol (SPINOL) were resolved with crude menthyl chloroformate by phase-transfer catalysis (PTC) in the presence of tetrabutylammonium bromide (TBAB). The reaction was carried out at 0℃-rt. The diastereomers of SPINOL bis-menthyl carbonate can be separated by simple crystallization using alcohol. The hydrolysis of the diastereomers was carried out via aqueous NaOH/EtOH solution. With this procedure, >99% ee of (R) and (5)-SPINOL could be obtained separately in 80.6% and 78.2% overall yields. This method was also applied to the resolution of the 4,4'- dibromo derivative (DBSPINOL) and BINOL.By combining resolution and protection of DBSPINOL with menthyl chloroformate, the enantiopure SPINOL and other 4,4'-derivatives have been synthesized effectively via (1S)-(-)-4,4'-dibromo-l,r-spirobiindane-7,7'-diyl bis-menthyl carbonate with n-BuLi following reacting with electrophiles of I2, MeI, CO2 and water. After cleavage of the menthyl dicarbonates through hydrolysis, enantiopure SPINOL, 4,4'-diiodo-l,l'-spirobiindane-7,7'-diol (DISPINOL), 4,4'-dimethyl-l,l'-spirobi-indane-7,7'-diol (DMSPINOL) and 7,7'-dihydroxy- 1,1'-spirobiindyl-4,4'-dicarboxylic acid (DCSPINOL) were obtained. Their absolute configurations were assigned to be (5) by chemicalcorrelation. DI-, DM- and DCSPINOL are new compounds.Low-temperature heat capacities of crystals of the (S)-SPINOL menthyl dicarbonates and (R)-BINOL menthyl dicarbonates were measured. Different data of heat capacity were given over the temperature range of 78 K (liquid nitrogen) to 370 K. Cp~T polynomial equations were fitted with the least square method by computer based on the above data. Similarities and differences of Cp~T curves were compared and reasons were analyzed. Decomposition temperature, enthalpy and entropy were calculated for samples decomposed in the measuring temperature range.By using the catalyst conveniently prepared in situ from Ti(O-iPr)4 and (R)-SPINOL, benzaldehyde was smoothly alkylated to secondary alcohol in high conversions and the enantioselectivity of the reaction decreased with the increase of temperature. DCM was the best solvent among the used. (S)-DBSPINOL, (S)-DMSPINOL and (S)-DISPINOL were also applied in the reaction. The addition reactions proceeded with high conversions and enantioselecties up to 88.2%.DCSPINOL were successfully immobilized to Merrifield type resin through amide bond and its application in titanium-catalyzed diethylzinc addition to aldehydes with 43% enantioselectivity.