Correction: Mechanochemical enzymatic resolution of N-benzylated-β3-amino esters

  1. Mario Pérez-Venegas1,
  2. Gloria Reyes-Rangel1,
  3. Adrián Neri2,
  4. Jaime Escalante2 and
  5. Eusebio Juaristi1,3

1Departamento de Química, Centro de Investigación y de Estudios Avanzados, Avenida I.P.N. 2508, Ciudad de México, 07360, Mexico
2Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Cuernavaca, Morelos, 62210, Mexico
3El Colegio Nacional, Luis Gonzáles Obregón 23, Centro Histórico, Ciudad de México, 06020, Mexico

  1. Corresponding author email

Guest Editor: J. G. Hernández
Beilstein J. Org. Chem. 2017, 13, 2128–2130. https://doi.org/10.3762/bjoc.13.210
Received 15 Sep 2017, Accepted 29 Sep 2017, Published 12 Oct 2017

Keywords: ball-milling; β3-amino acid; Candida antarctica lipase B; enzymatic resolution; mechanochemistry

The original published Tables 1–4 and Supporting Information File 1 contain some incorrect values. In this Correction article the whole corrected Tables are given. The positions of the correted values are described in detail in the paragraphs below.

In Table 1 in entry 5 the yield (column 3) has been corrected.

Table 1: Search of the best parameters in the enzymatic enantioselective hydrolysis of rac-1a under ball milling.

[Graphic 1]
entrya LAG additiveb yield (%)c (S)-1a/(R)-2a time (h) ee (S)-1a (%)d ee (R)-2a (%)d ce (%) Ef
1g 2M2B 51/49 0.5 99 80 55 46
2 2M2B 70/30 0.5 89 77 54 23
3 2M2B 51/49 1 99 95 51 >200
4 AcOEt 86/13 1 69 95 42 81
5 IPA 80/20 1 48 95 34 63
6 CH3CN 65/29 1 65 95 41 77
7 hexane 40/60 1 97 86 53 55
8 58/41 1 95 92 51 89
9g 58/42 1 93 86 52 45
10h 68/31 1 74 80 48 20

aReactions were carried out with 0.5 equivalents of water and 15 Hz of frequency. b0.2 mL of LAG additive was used. cDetermined after purification by flash chromatography. dDetermined by HPLC with chiral stationary phase. eCalculated from c = ees/(ees + eep). fE = ln[1 − c(1 + eep)]/ln[1 − c(1 − eep)]. g25 Hz of frequency was used. h0.25 equivalents of water were used.

In Table 2 in entry 4 the ee value of (S)-1 (column 5), and in entry 6 the yield (column 4) have been corrected.

Table 2: Substrate scope for the enzymatic resolution of N-benzylated-β3-amino esters.

[Graphic 2]
entrya rac R yield (%)b
(S)-1/(R)-2
eec (S)-1(%) [Graphic 3] eec (R)-2(%) [Graphic 4] cf (%) Eg absolute configurationh
1 1b CH3-(CH2)- 51/49 91 4.5 97 −36.5 48 >200 R
2 1c CH3-(CH2)2- 53/43 84 2.1 98 −45.2 46 >200 R
3 1d CH3-(CH2)3- 68/29 23 2.0 94 −35.3 20 40 R
4 1e CH3-(CH2)4- 74/24 16 0.2 94 −40.0 15 38 R
5 1f CH3-(CH2)5- 79/18 13 0.8 91 −39.7 13 24 R
6i 1g Ph 90/10 18 3.4 83 −35.0 18 13 S
7i 1h 4-MeO-Ph 89/10 1 −0.5 80 −31.7 1 9 S
8 1i t-Bu 89/4 4 −0.6 94 12.8 4 34 S

aReactions were carried out with 0.5 equivalents of water and 0.2 mL of 2M2B at 15 Hz during 1 h. bDetermined after purification by flash chromatography. cDetermined by HPLC with chiral stationary phase. d c = 0.33 in CH3Cl. ec = 0.33 in MeOH. fCalculated from c = ees/(ees + eep). gE = ln[1 − c(1 + eep)]/ln[1 − c(1 − eep)]. hAssigned by chemical correlation and by HPLC with chiral stationary phase. i0.75 equivalents of water were used.

In Table 3 entry 1 the ee of (S)-1a (column 4), in entry 2 the yield (column 3) and the c value (column 6), and in entry 3 the c value (column 6) have been corrected.

Table 3: Recycling capacity of immobilized CALB under HSBM conditions.

[Graphic 5]
entrya Recycling cycle yield (%)b (S)-1a/(R)-2a eec (S)-1a (%) eec (R)-2a (%) cd (%) Ee
1 51/49 99 95 51 >200
2 1 65/35 35 88 28 22
3 2 80/20 6 80 7 10
4 3 100/0 0

aReactions were carried out with 0.5 equivalents of water and 0.2 mL of 2M2B at 15 Hz during 1 h. bDetermined after purification by flash chromatography. cDetermined by HPLC with chiral stationary phase. dCalculated from c = ees/(ees + eep). eE = ln[1 − c(1 + eep)]/ln[1 − c(1 – eep)].

In Table 4 in entry 3 the yield (column 3) has been corrected.

Table 4: Scaling-up of the enzymatic hydrolysis reaction under ball-milling using substrate rac-1a.

[Graphic 6]
entrya catalyst/substrate (equiv) b yield (%)c (S)-1a/(R)-2a eed (S)-1a (%) eed (R)-2a (%) ce (%) Ef
1g 1/1 51/49 >99 95 51 >200
2 1/3 52/48 62 93 40 52
3 1/6 61/38 53 93 36 47
4 1/9 59/40 49 94 34 53

aReactions were carried out with 0.5 equivalents of water at 15 Hz during 1 h. b1 equivalent of enzyme = 40 mg; 1 equivalent of susbtrate = 82 mg. cDetermined after purification by flash chromatography. dDetermined by HPLC with chiral stationary phase. eCalculated from c = ees/(ees + eep). fE = ln[1 − c(1 + eep)]/ln[1 − c(1 − eep)]. g0.2 mL of LAG were used.

A corrected version of Supporting Information File 1 is also part of this Correction. The new Supporting Information File 1 is the complete file with the corrections marked in yellow color.

Supporting Information

Supporting Information File 1: Experimental section, NMR spectra, chromatograms and X-ray diffraction data.
Format: PDF Size: 7.0 MB Download

© 2017 Pérez-Venegas et al.; licensee Beilstein-Institut.
This is an Open Access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The license is subject to the Beilstein Journal of Organic Chemistry terms and conditions: (http://www.beilstein-journals.org/bjoc)

 
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