Title:A Facile, Efficient and Chemoseletive Deprotection of Silyl Ethers Using Zinc (II) Trifluoromethanesulfonate
Volume: 15
Issue: 3
Author(s): Kotthireddy Thirumal Reddy, Reddymasu Sreenivasulu, Deekala Veronica, Choragudi Chandrasekhar, Kowthalam Anitha and Rudraraju Ramesh Raju*
Affiliation:
- Department of Chemistry, Acharya Nagarjuna University, Nagarjuna Nagar-522 510, Andhra Pradesh,India
Keywords:
Facile method, RO-SiR3, chemoselective deprotection, RO-MOM, RO-PMB, RO-Bn, Zn(OTf)2.
Abstract: Background: A number of protective groups for hydroxyl functional groups have been developed
to date. Alcohols are most commonly protected as ethers and esters, where in alkyl and benzyl
ethers are strong protective groups while others, like THP, TBS, TPS and MEM/MOM ethers are acid
labile. Among all other hydroxyl protecting groups, Silyl ethers are the most frequently used protecting
groups because they are easily and efficiently installed and are stable to a variety of useful reagents
and reaction conditions. Among the silyl ethers, triethylsilyl (TES), tert-butyldimethylsilyl (TBDMS),
triisopropylsilyl (TIPS), and tert-butyldiphenylsilyl (TBDPS) moieties are the frequently used hydroxyl
protecting groups in multi step organic syntheses.
Methods: A mild, efficient and selective method for the deprotection of variety of silyl ethers developed
in high yields by using 20 mol % of Zinc (II) trifluoromethanesulfonate (Zn(OTf)2) at room temperature
in methanol as a solvent without affecting both the acid and base sensitive protecting groups was reported.
Results: To study the generality of this methodology, several silyl ethers were prepared from a variety
of substrates having different protecting groups and subjected to desilylation using Zn(OTf)2 in
MeOH.
Conclusion: In conclusion, mild and efficient protocols for the deprotection of variety of silyl ethers
using 20 mol % of Zn(OTf)2 at room temperature in MeOH have been established, in which both the
acid and base sensitive groups are unaffected.
