Abstract
Direct asymmetric hydration of alkenes with water as a nucleophile toward chiral secondary/tertiary alcohols with chem catalysis is an unmet challenge in organic chemistry, though it is the most atom economic synthetic pathway. An obstacle was the lack of the general knowledge on how to improve the nucleophilicity of water, because water is a poor nucleophile tutorially. The mechanism to enhance the nucleophilicity of water is elucidated here and three general principles were proposed via a discussion on recent reported data.