2017 年 75 巻 5 号 p. 538-547
The crystalline sponge method is a new X-ray technique for single crystal structure analysis that does not require crystallization of target samples. We report here the application of this method to the absolute configuration determination of chiral compounds. As heavy atoms are already installed in the host framework, the Bijvoet method, which uses X-ray anomalous scattering, can be applied without incorporating heavy atoms in the samples. Target compounds are focused on (1) chiral small molecules produced by enantioselective (catalytic) reactions of current interest and (2) isolated natural products supplied by co-workers. In most on-going researches, absolute structure determination has been a bottle-neck, thus demonstrating that the crystalline sponge method considerably accelerates researches in these area. Trace amount analysis on microgram quantities enabled dramatic scale-down and cost-down in the isolation, purification, and structure determination of natural products.