Lithium Triethylborohydride - Uses

Uses

Aldehydes and ketones rapidly utilizes 1 equivalent of LiTEBH to form the alcohol shown respectively in (1) and (2).

LiTEBH can be used to form the alcohol even when these compounds possess sterically hindered substituents as shown with 2,2,4,4-tetramethyl-3-pentanone in (3).

Esters and lactones rapidly take up 2 equivalents of LiTEBH, undergoing reduction to the alcohol and diol groups respectively. The example shown below involves the reduction of γ-butyrolactone to 1,4-butanediol which formed in a 94% yield in (4).

The opening of the epoxide ring with LiTEBH proceeds with exceptional regio- and stereo- selectivity, yielding only the Markovnikov alcohol. The example shown below is of 1,2-epoxybutane being reduced to give 1-methylcyclohexanol in (5).

The acetal and ketal will not be reduced by LiTEBH. LiTEBH can be used in the reductive cleavage of mesylates and tosylates. LiTEBH can selectively deprotect tertiary N-acyl groups without affecting secondary amide functionality. LiTEBH has also shown high reactivity toward ester groups by the selective reduction of the ester group of aromatic carboxylic acids to alcohols as shown in (6) and (7).

LiTEBH can also effectively reduce pyridine and isoquinolines to piperidines and tetrahydroisoquinolines respectively.
The reduction of β-hydroxysulfinyl imines with catecholborane and LiTEBH produces anti-1,3-amino alcohols shown in (8).