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

Mario Pérez-Venegas; Gloria Reyes-Rangel; Adrián Neri; Jaime Escalante; Eusebio Juaristi

doi:10.3762/bjoc.13.210

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

^¹ ,
^¹ ,
^² ,
^² and
^{^1,3}

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

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

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This correction refers to Beilstein J. Org. Chem. 2017, 13, 1728–1734. doi:10.3762/bjoc.13.167

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.

[Graphic 1] — **Table 1:** Search of the best parameters in the enzymatic enantioselective hydrolysis of *rac*-1a under ball milling.

^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 = ee_s/(ee_s + ee_p). ^fE = ln[1 − c(1 + ee_p)]/ln[1 − c(1 − ee_p)]. ^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.

[Graphic 2] — **Table 2:** Substrate scope for the enzymatic resolution of N-benzylated-β³-amino esters.

[Graphic 3] — **Table 2:** Substrate scope for the enzymatic resolution of N-benzylated-β³-amino esters.

^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. ^dc = 0.33 in CH₃Cl. ^ec = 0.33 in MeOH. ^fCalculated from c = ee_s/(ee_s + ee_p). ^gE = ln[1 − c(1 + ee_p)]/ln[1 − c(1 − ee_p)]. ^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.

[Graphic 5] — **Table 3:** Recycling capacity of immobilized CALB under HSBM conditions.

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

[Graphic 6] — **Table 4:** Scaling-up of the enzymatic hydrolysis reaction under ball-milling using substrate *rac*-1a.

^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 = ee_s/(ee_s + ee_p). ^fE = ln[1 − c(1 + ee_p)]/ln[1 − c(1 − ee_p)]. ^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.
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entry^a	LAG additive^b	yield (%)^c (S)-1a/(R)-2a	time (h)	ee (S)-1a (%)^d	ee (R)-2a (%)^d	c^e (%)	E^f

1^g	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
9^g	–	58/42	1	93	86	52	45
10^h	–	68/31	1	74	80	48	20



entry^a	rac	R	yield (%)^b (S)-1/(R)-2	ee^c (S)-1(%)		ee^c (R)-2(%)		c^{f (}%)	E^g	absolute configuration^h

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



entry^a	Recycling cycle	yield (%)^b (S)-1a/(R)-2a	ee^c (S)-1a (%)	ee^c (R)-2a (%)	c^d (%)	E^e

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	–	–	–



entry^a	catalyst/substrate (equiv) ^b	yield (%)^c (S)-1a/(R)-2a	ee^d (S)-1a (%)	ee^d (R)-2a (%)	c^e (%)	E^f

1^g	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

aromatic	the word “aromatic”
aromatic aldehyde	the word “aromatic” OR “aldehyde”
+aromatic +aldehyde	both words “aromatic” AND “aldehyde”
+aromatic -aldehyde	the word “aromatic” but NOT “aldehyde”
“aromatic aldehyde”	the exact phrase “aromatic aldehyde”
benz*	words which begin with “benz”, such as “benzene” or “benzyl”
benz*yl	words that begin with “benz” and end with “yl”, such as “benzyl” or “benzoyl”
benzyl~	words that are close to the word “benzyl”, such as “benzoyl” (i.e., fuzzy search)