Preparation of a chiral synthon for an HBV inhibitor: enzymatic asymmetric hydrolysis of (1α,2β,3α)-2-(benzyloxymethyl)cyclopent-4-ene-1,3-diol diacetate and enzymatic asymmetric acetylation of (1α,2β,3α)-2-(benzyloxymethyl)cyclopent-4-ene-1,3-diol

Patel, Ramesh N.; Banerjee, Amit; Pendri, Yadagiri; Liang, Jing; Chen, Chung‐Pin; Mueller, Richard H.

doi:10.1016/j.tetasy.2005.08.061

Cited by 21 publications

(11 citation statements)

References 34 publications

(33 reference statements)

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“…[17][18][19] Following this publication, numerous reports of the enantioselective lipase-mediated acylation of amines appeared in the 1990s and the field has since gained significant industrial academic and significance, as described in a number of recent reviews. [20][21][22][23][24][25][26][27][28][29] Herein we report the highly enantioselective CALB/Novozym 435-and amano lipase PS-catalyzed acylation of 1-(3 0 -bromophenyl)ethylamine (RS)-1 with ethyl 2-methoxyacetate as the acyl donor, to furnish the (S)-amine (S)-1 and (R)-2 00 -methoxyacetamide (R)-2 in high yield (90-96%) and high enantiopurity (ee >99%). The enantiomers of 1 and 2 were required with enantiopurities >99.5% as intermediates in the synthesis of IB kinase (IKK) modulators and other pharmaceuticals.…”

Section: Introductionmentioning

confidence: 99%

Enantioselective enzymatic acylation of 1-(3′-bromophenyl)ethylamine

Gill

Das

Patel

2007

Tetrahedron: Asymmetry

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Section: Introductionmentioning

confidence: 99%

Enantioselective enzymatic acylation of 1-(3′-bromophenyl)ethylamine

Gill

Das

Patel

2007

Tetrahedron: Asymmetry

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“…PFL has been used in many biotransformations (Gilbert, 1993;Im et al, 2003;Miyazawa et al, 2005;Patel et al, 2006;Singh and Banerjee, 2005;Wu and Tsai, 2004;Zhou and Xu, 2005;Zheng et al, 2006), and it is a good example of an enzyme suffering interfacial activation Jaeger et al, 1993;Kim et al, 1997;Palomo et al, 2003Palomo et al, , 2004Palomo et al, , 2005Schrag et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

Improved catalytic properties of immobilized lipases by the presence of very low concentrations of detergents in the reaction medium

Fernández‐Lorente

Palomo

Cabrera

et al. 2006

Biotech & Bioengineering

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The addition of a very small concentration of a detergent (in many instances under the critical micellar concentration (cmc)) has been found to greatly increase the activity of immobilized lipases, using those from Pseudomonas fluorescens (PFL) and Candida antarctica (isoform B) as model enzymes. However, the detergents may also have a negative effect on enzyme activity; in fact, for all enzyme preparations and substrates the activity/detergent concentration curve reached a maximum value and started to decrease, in many instances even under the initial value. The concentration and nature of the detergent (SDS, CTAB, Triton X-100, or X-45) that permitted the maximum hyperactivation was different depending on the substrate. The best hyperactivation values promoted by the presence of detergent were over a 20-fold factor. The presence of detergents permitted the inhibition of lipases by irreversible covalent inhibitors (e.g., 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride) (AEBSF) while the enzyme, in the absence of detergent, is not inhibited by these irreversible inhibitors. This suggested that the main effect of the detergents is to shift the conformational equilibrium of lipases toward the open form. Moreover, the presence of detergents also permitted to improve the enantioselectivity exhibited by the immobilized lipases in some cases. For example, the enantioselectivity of PFL-glyoxyl agarose increased from 40 to more than 100 in the hydrolysis of (+/-)-2-hydroxy-4-phenylbutyric acid ethyl ester by using 0.1% CTAB.

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“…lipase (Scheme 15). 128 The formed complementary mono-acetates (1R,4S,5R)-63 and (1S,4R,5S)-63 could both be converted to Intermediate 65. 129 Chemical synthesis subsequently provided entecavir.…”

Section: Scheme 10mentioning

confidence: 99%