Joginder S. Bajwa

Selective deprotection of alkyl t-butyldimethylsilyl ethers in the presence of aryl t-butyldimethylsilyl ethers with bismuth bromide

Abstract Alkyl t -butyldimethylsilyl ethers can be selectively cleaved in the presence of aryl ethers using a catalytic amount of bismuth bromide in wet acetonitrile at ambient temperatures.

In-situ generation of Et3SiBr from BiBr3 and Et3SiH and its use in preparation of dialkyl ethers

Abstract The reported BiBr 3 –Et 3 SiH catalyzed reductive etherifications of silyl ethers with carbonyl compounds are shown to be catalyzed by the in situ formed Et 3 SiBr and verified by an independent use of the commercial reagent. As Et 3 SiBr is moisture sensitive and is not readily available, this in situ generation is still recommended as the method of choice. Utilizing this method, several alcohols were transformed under very mild conditions into dialkyl ethers via their silyl intermediates, such as TES, TBDMS, and TIPS.

Chemoselective deprotection of tertiary benzylamines and reduction of carbon–carbon double bonds in the presence of benzyl and benzyloxymethyl ethers

Abstract Catalytic transfer hydrogenation using 10% Pd–C in the presence of 1,4-cyclohexadiene as the hydrogen donor selectively debenzylates amines and reduces carbon–carbon double bonds while leaving benzyl and benzyloxymethyl ethers intact.

Etherification of alkoxydialkylsilanes with carbonyl compounds

Abstract A novel method for preparing ethers from alkoxydialkylsilanes and carbonyl compounds through reductive etherification is described. The salient feature in this method is the utilization of internal hydrogen as the hydride source for reducing the oxonium intermediate generated by using the Cl(R) 2 SiBr[BiBr 3 /Cl(R) 2 SiH] catalytic system.

Isotopic labeling as a probe in the study of a degenerate Payne Rearrangement in a tertiary epoxide system

Through the use of isotropic labeling, it has been shown that epoxide 6 undergoes Payne Rearrangement under basic protic conditions (NaOD/D2O/rt). However, no rearrangement took place when epoxide 6 was exposed to basic aprotic conditions (NaH/THF/reflux).