TBS Protection

Common Conditions (Protection):

TBS-Cl

TBS-Cl effectively protects primary and secondary alcohols (not tertiary). TBS-Cl reacts very slowly when used without basic activators (ex. imidazole or DMAP). DMF is the most common solvent.^[1]

Examples

TBS-OTf

TBS-OTf is a very powerful silylating agent, and is capable of protecting primary, secondary, and teriary alcohols. The base is usually 2,6-lutidine and the solvent DCM.^[1]

Examples

Common Conditions (Deprotection):

TBAF

Tetrabutylammonium fluoride (TBAF) is the most popular fluoride reagent for TBS deprotection. The basicity of fluoride can sometimes cause undesired side reactions.^[1]

Examples

HCl

HCl effectively removes TBS groups. MeOH is often used as the solvent. Other acid sensitive functionalities may also be affected.^[1]

Examples

Cs₂CO₃

Cs2CO3 (or K2CO3) is sometimes used to deprotect phenolic TBS ethers. Sometimes phenolic TBS ethers can be selectively deprotected in the presence of alkyl TBS ethers.^[1][2]

Examples

References:

1) Kocienski, P. J.; Protecting Groups, 3rd Edition

2) Wuts, P. G. M.; Greene, T. W.; Greene's Protective Groups in Organic Synthesis, 4th Edition