Influence of different protecting groups on the regioselectivity of the hydrotelluration reaction of hydroxy alkynes

The influence of protecting groups on the synthesis of regio- and stereodefined vinyl tellurides derived from the reaction of BuTeNa and propargylic- or homo-propargylic alcohols showed that TIPS silyl ether is useful as a regiodirecting group. The application of the methodology to the synthesis of a fragment of (±)-Seselidiol, a natural product, demonstrated the applicability of the new methodology

Lipase-Catalyzed Kinetic Resolution of Aryltrimethylsilyl Chiral Alcohols

Lipase-catalyzed kinetic resolution of aryltrimethylsilyl chiral alcohols through a transesterification reaction was studied. The optimal conditions found for the kinetic resolution of m- and p-aryltrimethylsilyl chiral alcohols, led to excellent results, high conversions (c = 50%), high enantiomeric ratios (E > 200) and enantiomeric excesses for the remaining (S)-alcohol and (R)-acetylated product (>99%). However, kinetic resolution of o-aryltrimethylsilyl chiral alcohols did not occur under the same conditions applied to the other isomers

Enzymatic reactions involving the heteroatoms from organic substrates

ABSTRACT Several enzymatic reactions of heteroatom-containing compounds have been explored as unnatural substrates. Considerable advances related to the search for efficient enzymatic systems able to support a broader substrate scope with high catalytic performance are described in the literature. These reports include mainly native and mutated enzymes and whole cells biocatalysis. Herein, we describe the historical background along with the progress of biocatalyzed reactions involving the heteroatom(S, Se, B, P and Si) from hetero-organic substrates