Lipase catalysis in the optical resolution of 2-amino-1-phenylethanol derivatives

Enantiomers of adrenaline-type amino alcohols by Burkholderia cepacia lipase-catalyzed asymmetric acylation

“…Thus, octopamine, as its salts with optically active acids, has been resolved by fractional crystallization, 7 while the lipase-catalyzed kinetic resolution has served as one of the most fascinating methods in the case of various ring-substituted 2-amino-1-phenylethanols. [8][9][10][11] We previously used Burkholderia cepacia lipase (lipase PS)-catalyzed asymmetric acylation of various 2-amino-1-phenylethanols with an acid anhydride in toluene/THF (3:1) as a highly effective method to pure enantiomers. 10 The addition of THF was necessary in order to improve the solubility of 2-amino-1-phenylethanols while the ring substituents were typically unreactive under the reaction conditions.…”

The first synthesis of optically active 1-substituted taurines

“…IR spectra were taken on a Brucker Vector 22 FT-IR spectrophotometer in KBr pellet. The analytical data of all known compounds are identical to those earlier reported in the literature [27][28][29].…”

Structural and Experimental Evidence for the Enantiomeric Recognition toward a Bulky sec-Alcohol by Candida antarctica Lipase B

“…A similar result using N-Cbz-protected rac-2-amino-1phenylethanol with n-PrCO 2 CH 2 CF 3 was previously reported, but the resulting ester had low enantiopurity with 65% ee at 53% conversion (E = ∼ 10). 15 CAL-A was the sole hydrolase that exhibited the opposite enantioselectivity, providing (R)-2a with 63% ee at 50% conversion in 6 h. In addition, CAL-B converted rac-1a to (S)-2a with a conversion of 12% in 48 h. We were intrigued by the unexpected reactivity of CAL-B because this reaction could only occur if the medium pocket of CAL-B was able to accept one of the large substituents (the phenyl or the N-Boc-aminomethylene) of (S)-1a, and this seemed unlikely based on the known size of CAL-B's medium pocket.…”

“…However, most of the examples required multistep processes to obtain the desired products. In addition, the hydrolase-catalyzed resolution of rac -2-amino-1-arylethanols has been reported, but the resolution process afforded unsatisfactory enantiomeric purities (65% ee) . Hence, we explored an efficient and effective hydrolase-catalyzed resolution process.…”

“…In addition, the hydrolase-catalyzed resolution of rac-2-amino-1arylethanols has been reported, but the resolution process afforded unsatisfactory enantiomeric purities (65% ee). 15 Hence, we explored an efficient and effective hydrolasecatalyzed resolution process. N-Boc-protected rac-2-amino-1phenylethanol (1a; Boc = t-butyloxycarbonyl) was chosen as a substrate for the initial screening of hydrolases.…”