Hydroboration–oxidation reaction

"The four-center transition state for hydroboration of alkenes discussed above implies that addition of the B-H bond to a double bond proceeds in a syn-manner."

"The facile reactions of olefins and dienes with various hydroborating agents makes a variety of organoboranes readily available. Organoboranes tolerate many functional groups and are formed in a stereospecific manner. The boron atom in these organoboranes can be readily substituted with a variety of functional groups."

"The hydration of alkenes via hydroboration-oxidation … provides a valuable tool for the synthesis of a wide variety of alcohols of predictable regio- and stereochemistry. … The mono- and dialkylboranes are themselves useful hydroborating agents for sterically less hindered alkenes."

"The rates of hydroboration of alkenes with dialkylboranes vary over a wide range."

"An important feature of the hydroboration reaction is the regioselectivity observed with unsymmetrical alkenes. Generally, boron attacks positions of highest electron density and lowest steric congestion. This working hypothesis rationalizes the regioselectivity and stereo- selectivity of most hydroboration reactions."