| Literature DB >> 35480442 |
Songsoon Park1,2, Hyeon-Kyu Lee1,2.
Abstract
Efficient kinetic resolution (KR) occurs in asymmetric transfer hydrogenation (ATH) reactions of racemic 3-aryl-1-indanones using commercial (R,R)- or (S,S)-Ts-DENEB as a catalyst, a 1 : 5 mixture of HCO2H and Et3N as a hydrogen source and MeOH as solvent. This process at room temperature produces near equal yields of cis-3-arylindanols with high dr and ee, and unreacted 3-arylindanones with excellent ee. Stereoselective transformations of 3-arylindanols and 3-arylindanones, generated by using the ATH-KR protocol, were carried out to form (+)-indatraline and synthetically valuable (R)-6-methyl-4-phenylcoumarine, which is a key intermediate in the preparation of (R)-tolterodine, (S)-4-aryl-3,4-dihydroquinoline-2(1H)-one and (S)-4-aryl-3,4-dihydroisoquinoline-1(2H)-one. This journal is © The Royal Society of Chemistry.Entities:
Year: 2021 PMID: 35480442 PMCID: PMC9036567 DOI: 10.1039/d1ra04538e
Source DB: PubMed Journal: RSC Adv ISSN: 2046-2069 Impact factor: 3.361
Fig. 1Examples of biologically active 3-(aryl)-substituted indanes.
Scheme 1ATH reactions of 3-methoxycarbonyl-1-indanone (3) and 3-aryl-1-indanone 1s.
Scheme 2Racemization experiments of optically active 3-substituted-1-indanones.
Optimization of conditions for ATH-KR reactions of 3-arylindanone 1sa
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| Entry | Cat. | F/T ratio | Solvent | Rxn time (h) | Conv. | Indanol (2s) | Indanone (1s) | ||
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| ee (%) of | ee (%) of | ee (%) of recovered 1s | ||||||
| 1 | C1 | 5 : 2 | DCE | 6 | 53 | 93 : 7 | 99 | 47 | 97 |
| 2 | C2 | 5 : 2 | DCE | 6 | 56 | 92 : 8 | 99 | 15 | 99 |
| 3 | C3 | 5 : 2 | DCE | 6 | 56 | 92 : 8 | >99 | 40 | >99 |
| 4 | C1 | 5 : 2 | DCE | 24 | 65 | 80 : 20 | >99 | 58 | 96 |
| 5 | C2 | 5 : 2 | DCE | 24 | 77 | 76 : 24 | 98 | 29 | 91 |
| 6 | C3 | 5 : 2 | DCE | 24 | 57 | 88 : 12 | >99 | 42 | >99 |
| 7 | C3 | 1 : 1 | DCE | 6 | 53 | 83 : 17 | >99 | 51 | 57 |
| 8 | C3 | 1 : 1 | DCE | 24 | 58 | 87 : 13 | >99 | 50 | 93 |
| 9 | C3 | 1 : 5 | DCE | 6 | 53 | 89 : 11 | >99 | 53 | 83 |
| 10 | C3 | 1 : 5 | DCE | 24 | 55 | 91 : 9 | >99 | 58 | 95 |
| 11 | C3 | 1 : 5 | CH3CN | 6 | 32 | 100 : 0 | 99 | — | 48 |
| 12 | C3 | 1 : 5 | CH2Cl2 | 6 | 28 | 99 : 1 | >99 | — | 36 |
| 13 | C3 | 1 : 5 | THF | 6 | 31 | 100 : 0 | 99 | — | 46 |
| 14 | C3 | 1 : 5 | EtOAc | 6 | 44 | 99 : 1 | >99 | — | 80 |
| 15 | C3 | 1 : 5 | DMF | 6 | 46 | 100 : 0 | 99 | — | 83 |
| 16 | C3 | 1 : 5 | Neat | 6 | 50 | 95 : 5 | 99 | — | 96 |
| 17 | C3 |
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| 18 | C3 | 1 : 5 | MeOH | 20 | 50 | 100 : 0 | 99 | — | 99 |
Reaction conditions: substrate (1 eq., 0.25 mmol), Cat. (1 mol%); FA : TEA = 10 eq. : 4 eq. (5 : 2), 4 eq. : 4 eq. (1 : 1), or 3 eq. : 15 eq. (1 : 5); solvent (0.2 M); rt, under N2 atmosphere.
Determined by using 1H-NMR.
Determined by using chiral HPLC.
Scheme 3Synthesis of substituted 3-aryl-indanones 1.
ATH-KR reactions of 3-arylindanonesa
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|---|---|---|---|---|---|---|---|---|---|---|---|
| Entry | Substrate (1) | Time (h) | Conv | Indanol (2) | Recovered indanone | Entry | Substrate (1) | Time (h) | Conv | Indanol (2) | Recovered indanone |
| 1 |
| 9 | 50 |
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| 15 |
| 6 | 50 |
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| 2 |
| 6 | 50 |
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| 16 |
| 8 | 51 |
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| 3 |
| 10 | 50 |
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| 17 |
| 8 | 52 |
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| 4 |
| 10 | 50 |
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| 18 |
| 9 | 50 |
|
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| 5 |
| 6 | 50 |
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| 19 |
| 6 | 50 |
|
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| 6 |
| 10 | 50 |
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| 20 |
| 11 | 50 |
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| 7 |
| 17 | 50 |
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| 21 |
| 11 | 52 |
|
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| 8 |
| 7 | 50 |
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| 22 |
| 10 | 52 |
|
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| 9 |
| 7 | 50 |
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| 23 |
| 5 | 51 |
|
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| 10 |
| 7 | 50 |
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| 24 |
| 10 | 51 |
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| 11 |
| 8 | 50 |
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| 25 |
| 7 | 51 |
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| 12 |
| 7 | 50 |
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| 26 |
| 8 | 50 |
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| 13 |
| 7 | 49 |
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| 27 |
| 6 | 50 |
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| 14 |
| 7 | 51 |
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Reaction conditions: substrate 1 (1 eq., 0.5 mmol), (R,R)-Ts-DENEB catalyst (1 mol%), FA : TEA (3 eq. : 15 eq.), MeOH (0.2 M, 2.5 mL), rt (23 °C) under N2 atmosphere.
Determined by using 1H NMR.
Yields correspond to isolated yields, % ee's were determined by chiral HPLC. Absolute stereochemistry was determined by comparison with optical rotation of known compounds.
2 mol% of (R,R)-Ts-DENEB catalyst was used.
(S,S)-Ts-DENEB catalyst (1 mol%) was used.
Fig. 2Proposed asymmetric induction model[41] in the ATH-KR of racemic-1a to (R,R)-2a and (S)-1a.
Scheme 4Synthetic applications.