22810-55-5

Upstream product

• 269401-67-4 (S)-2-methoxy-2-phenyl-1-ethylmethanesulfonate 
• 61825-54-5 (S)-2-methoxy-2-phenylethylene para-toluenesulphonate 
• 3558-61-0 (S)-methyl 2-methoxy-2-phenylacetate 
• 21210-43-5 (S)-Methyl mandelate 
• 66051-01-2 (S)-2-methoxy-2-phenylethanol 
• 26164-26-1 (S)-2-methoxy-2-phenylacetic acid 
• 17199-29-0 (S)-Mandelic acid 

Downstream Products

• 116487-02-6 (+)-Neomenthyl 2-phenyl-2-methoxyethyl sulfide 
• 269401-47-0 (S)-2-methoxy-2-phenyl-ethylmethanethiosulfonate 

Relevant academic research and scientific papers

Silylium-Catalyzed Carbon–Carbon Coupling of Alkynylsilanes with (2-Bromo-1-methoxyethyl)arenes: Alternative Approaches

The catalytic activation of alkynylsilanes towards 2-halo-1-alkoxyalkyl arenes gives β-halo-substituted alkynes. It involves the chemoselective substitution of an alkoxide by an alkyne in the presence of a neighboring C(sp3)–Br bond in a cationic C–C bond-forming event. Two complementary protocols to accomplish this new transformation are reported. The outcome of a direct approach based on mixing the precursors with a freshly prepared solution of the active catalytic species (TMSNTf2) is compared with an alternative based on smooth release of the required silylium ions upon selective activation of the alkyne by gold(I) (JohnPhosAuNTf2). The two approaches gave satisfactory results to access this otherwise elusive alkynylation process, which furnishes 4-bromo-substituted alkynes and tolerates various functional groups.

Covalent modification of subtilisin Bacillus lentus Cysteine mutants with enantiomerically pure chiral auxiliaries causes remarkable changes in activity

Methanethiosulfonate reagents may be used to introduce virtually unlimited structural modifications in enzymes via reaction with the thiol group of cysteine. The covalent coupling of enantiomerically pure (R) and (S) chiral auxiliary methanethiosulfonate ligands to cysteine mutants of subtilisin Bacillus lentus induces spectacular changes in catalytic activity between diastereomeric enzymes. Amidase and esterase kinetic assays using a low substrate approximation were used to establish k(cat)/K(M) values for the chemically modified mutants, and up to 3-fold differences in activity were found between diastereomeric enzymes. Changing the length of the carbon chain linking the phenyl or benzyl oxazolidinone ligand to the mutant N62C by a methylene unit reverses which diastereomeric enzyme is more active. Similarly, changing from a phenyl to benzyl oxazolidinone ligand at S166C reverses which diastereomeric enzyme is more active. Chiral modifications at S166C and L217C give CMMs having both high esterase k(cat)/K(M)'s and high esterase to amidase ratios with large differences between diastereomeric enzymes. Copyright (C) 2000 Elsevier Science Ltd.