Chiral Silver Alkoxide Catalyzed Asymmetric Mannich-Type Reaction of Alkenyl Esters with Isatin Imines

Akira Yanagisawa; Kyonosuke Gomi; Ririko Uga; Ryusei Suga

doi:10.1055/a-2551-4541

Synlett, Table of Contents

Synlett 2025; 36(11): 1524-1529
DOI: 10.1055/a-2551-4541

letter

Chiral Silver Alkoxide Catalyzed Asymmetric Mannich-Type Reaction of Alkenyl Esters with Isatin Imines

Akira Yanagisawa∗

,

Kyonosuke Gomi

,

Ririko Uga

,

Ryusei Suga

Abstract

All articles of this category

Abstract

A catalytic enantioselective Mannich-type reaction of alkenyl esters with isatin imines was achieved by using a Tol-BINAP·AgSbF₆ complex as the chiral precatalyst and N,N-diisopropylethylamine as the base precatalyst in the presence of methanol. Optically active 3-alkylated 3-amino-2-oxindoles having up to 98% ee were diastereoselectively obtained in moderate to high yields not only from acyclic alkenyl esters but also from cyclic esters through the in situ generated chiral silver enolates.

Key words

alkenyl ester - asymmetric catalysis - isatin imine - Mannich-type reaction - silver

Full Text

References

References and Notes
1 Kitamura H, Kato A, Esaki T. Eur. J. Pharmacol. 2001; 418: 225
2 Hara N, Nakamura S, Sano M, Tamura R, Funahashi Y, Shibata N. Chem. Eur. J. 2012; 18: 9276

For reviews on the reactions of isatin imines, see:

3a Singh GS, Desta ZY. Chem. Rev. 2012; 112: 6104
3b Chauhan P, Chimni SS. Tetrahedron: Asymmetry 2013; 24: 343
3c Ziarani GM, Moradi R, Lashgari N. Tetrahedron: Asymmetry 2015; 26: 517
3d Yu J.-S, Zhou F, Liu Y.-L, Zhou J. Synlett 2015; 26: 2491
3e Kaur J, Chimni SS. Org. Biomol. Chem. 2018; 16: 3328
3f Ziarani GM, Moradi R, Lashgari N. Tetrahedron 2018; 74: 1323
3g Brandão P, Burke AJ. Tetrahedron 2018; 74: 4927
3h Egorov IN, Santra S, Kopchuk DS, Kovalev IS, Zyryanov GV, Majee A, Ranu BC, Rusinov VL, Chupakhin ON. Adv. Synth. Catal. 2020; 362: 4293
3i Hou X.-Q, Du D.-M. Adv. Synth. Catal. 2020; 362: 4487
3j Yasukawa N, Nakamura S. Chem. Commun. 2023; 59: 8343

For examples using chiral thiourea organocatalysts, see:

4a Yan W, Wang D, Feng J, Li P, Zhao D, Wang R. Org. Lett. 2012; 14: 2512
4b Li T.-Z, Wang X.-B, Sha F, Wu X.-Y. J. Org. Chem. 2014; 79: 4332
4c Liu T, Liu W, Li X, Peng F, Shao Z. J. Org. Chem. 2015; 80: 4950
4d Engl OD, Fritz SP, Wennemers H. Angew. Chem. Int. Ed. 2015; 54: 8193
4e Gajulapalli VP. R, Jafari E, Kundu DS, Mahajan S, Peuronen A, Rissanen K, Enders D. Synthesis 2017; 49: 4986
4f Sivamuthuraman K, Kesavan V. J. Org. Chem. 2018; 83: 8936
4g Xu H, Kang T.-C, Sha F, Wu X.-Y. Org. Biomol. Chem. 2018; 16: 5780
4h Liu Y, Wang J, Wei Z, Cao J, Liang D, Lin Y, Duan H. Org. Biomol. Chem. 2018; 16: 8927
4i Chang Z, Ye C, Fu J, Chigumbu P, Zeng X, Wang Y, Jiang C, Han X. Adv. Synth. Catal. 2019; 361: 5516
4j Franc M, Urban M, Císařová I, Veselý J. Org. Biomol. Chem. 2019; 17: 7309
4k Rodríguez-Ferrer P, Sanz-Novo M, Maestro A, Andrés JM, Pedrosa R. Adv. Synth. Catal. 2019; 361: 3645
4l Zhu W.-R, Liu K, Weng J, Huang W.-H, Huang W.-J, Chen Q, Lin N, Lu G. Org. Lett. 2020; 22: 5014
4m Kaur J, Kaur BP, Islam N, Chauhan P, Chimni SS. Eur. J. Org. Chem. 2021; 5193

For examples using chiral squaramide organocatalysts, see:

5a Wang X.-B, Li T.-Z, Sha F, Wu X.-Y. Eur. J. Org. Chem. 2014; 739
5b Kaur J, Kumari A, Bhardwaj VK, Chimni SS. Adv. Synth. Catal. 2017; 359: 1725
5c İşibol D, Karahan S, Tanyeli C. Tetrahedron Lett. 2018; 59: 541
5d Ričko S, Meden A, Ciber L, Štefane B, Požgan F, Svete J, Grošelj U. Adv. Synth. Catal. 2018; 360: 1072
5e Zhao B.-L, Du D.-M. Org. Lett. 2018; 20: 3797
5f Li B.-Y, Du D.-M. Adv. Synth. Catal. 2018; 360: 3164
5g Huang Q, Zhang L, Cheng Y, Li P, Li W. Adv. Synth. Catal. 2018; 360: 3266
5h Wu G, Xu H, Liu Z, Liu Y, Yang X, Zhang X, Huang Y. Org. Lett. 2019; 21: 7708
5i Karahan S, Tanyeli C. Org. Biomol. Chem. 2020; 18: 479
5j Li Z, Peng J, He C, Xu J, Ren H. J. Org. Chem. 2020; 85: 3894
5k Urban M, Nigríni M, Císařová I, Veselý J. J. Org. Chem. 2021; 86: 18139
5l Torán R, Puchán D, Sanz-Marco A, Vila C, Pedro JR, Blay G. Org. Biomol. Chem. 2022; 20: 8395

For examples using other chiral organocatalysts, see:

6a Guo Q.-X, Liu Y.-W, Li X.-C, Zhong L.-Z, Peng Y.-G. J. Org. Chem. 2012; 77: 3589
6b Tang Z, Shi Y, Mao H, Zhu X, Li W, Cheng Y, Zheng W.-H, Zhu C. Org. Biomol. Chem. 2014; 12: 6085
6c Wang Y, Shi F, Yao X.-X, Sun M, Dong L, Tu S.-J. Chem. Eur. J. 2014; 20: 15047
6d Bai M, Cui B.-D, Zuo J, Zhao J.-Q, You Y, Chen Y.-Z, Xu X.-Y, Zhang X.-M, Yuan W.-C. Tetrahedron 2015; 71: 949
6e Zhu Y, Zhang E, Luo C, Li X, Cheng J.-P. Tetrahedron 2015; 71: 4090
6f Dai J, Xiong D, Yuan T, Liu J, Chen T, Shao Z. Angew. Chem. Int. Ed. 2017; 56: 12697
6g Hajra S, Laskar S, Jana B. Chem. Eur. J. 2019; 25: 14688
6h Li G, Liu M, Zou S, Feng X, Lin L. Org. Lett. 2020; 22: 8708
6i Zhao M, Zhao Z, Wei Z, Cao J, Liang D, Lin Y, Duan H. J. Org. Chem. 2024; 89: 4474

7a Liu X, Zhang J, Zhao L, Ma S, Yang D, Yan W, Wang R. J. Org. Chem. 2015; 80: 12651
7b Lin H, Zhou Z, Cai J, Han B, Gong L, Meggers E. J. Org. Chem. 2017; 82: 6457
7c Sawa M, Miyazaki S, Yonesaki R, Morimoto H, Ohshima T. Org. Lett. 2018; 20: 5393
7d Yu J.-S, Noda H, Kumagai N, Shibasaki M. Synlett 2019; 30: 488
7e Fan Y, Lu J, Sha F, Li Q, Wu X.-Y. J. Org. Chem. 2019; 84: 11639
7f Shen Y.-B, Qian H.-L, Yang L, Zhou S, Rao H.-W, Wang Z.-H, You Y, Zhang Y.-P, Yin J.-Q, Zhao J.-Q, Zhang W, Yuan W.-C. Org. Lett. 2024; 26: 1699

8 Yanagisawa A, Lin Y, Miyake R, Yoshida K. Org. Lett. 2014; 16: 86

9a Gil J, Medio-Simon M, Mancha G, Asensio G. Eur. J. Org. Chem. 2005; 1561
9b Claraz A, Leroy J, Oudeyer S, Levacher V. J. Org. Chem. 2011; 76: 6457

In our previous study on the chiral silver(I)-catalyzed asymmetric allylation of aldehydes, we showed that a considerable amount of an inert 2:1 complex of BINAP/silver(I) salt was formed, accompanied by a reactive 1:1 complex, when BINAP was added to an equimolar amount of the silver salt in MeOH. In the reaction, a 0.6:1 mixture of BINAP/silver(I) salt was found to produce the desired 1:1 complex without the formation of the 2:1 complex:

10a Yanagisawa A, Kageyama H, Nakatsuka Y, Asakawa K, Matsumoto Y, Yamamoto H. Angew. Chem. Int. Ed. 1999; 38: 3701
10b Yanagisawa A, Nakatsuka Y, Asakawa K, Kageyama H, Yamamoto H. Synlett 2001; 69
10c Yanagisawa A, Nakatsuka Y, Asakawa K, Wadamoto M, Kageyama H, Yamamoto H. Bull. Chem. Soc. Jpn. 2001; 74: 1477

11 Asymmetric Mannich-Type Reaction Catalyzed by (R)-Tol-BINAP·AgSbF₆ and (i-Pr)₂NEt; Typical Procedure: Synthesis of 1-Benzyl-3-((4-bromophenyl)amino)-3-(1-oxo-1-phenylpropan-2-yl)indolin-2-one (3aa) A mixture of AgSbF₆ (27.5 mg, 0.08 mmol), (R)-Tol-BINAP (27.2 mg, 0.04 mmol), and isatin imine 2a (195.6 mg, 0.5 mmol) was dissolved in anhydrous THF (6 mL) under an argon atmosphere and with direct light excluded, and stirred at room temperature for 20 min. To the resulting solution were added CH₃OH (40.6 μL, 1.0 mmol) and (i-Pr)₂NEt (17 μL, 0.10 mmol) successively at –40 °C. The mixture was stirred at that temperature for 5 min, then alkenyl trifluoroacetate 1a (142.0 μL, 0.75 mmol) was added dropwise to the resulting solution at –40 °C. After stirring for 1.5 h at that temperature, the mixture was treated with MeOH (3 mL). The mixture was then filtered through a glass filter funnel filled with Celite^®, washed with EtOAc, and the combined filtrate and washes were concentrated in vacuo. The residual crude product was purified by column chromatography on silica gel to give the corresponding β-amino ketone 3aa (255.7 mg, 97% yield). The diastereomeric ratio was determined to be 92:8 by ¹H NMR analysis. The enantiomeric ratio of the major isomer was determined to be 86% ee by HPLC analysis using a chiral column [Daicel Chiralpak AD-3, hexane–i-PrOH (4:1), flow rate = 1.0 mL/min] t ₁ = 17.9 min (minor), t ₂ = 117.6 min (major). The enantiomeric ratio of the minor isomer was determined to be 4% ee by HPLC analysis using a chiral column [Daicel Chiralpak AD-3, hexane–i-PrOH (4:1), flow rate = 1.0 mL/min] t ₁ = 35.7 min (major), t ₂ = 64.0 min (minor). [α]²¹.⁴ _D +44.2 (c 1.0, CHCl₃, 86% ee); mp 48–53 °C. ¹H NMR (392 MHz, CDCl₃): δ = 7.90 (d, J = 7.1 Hz, 2 H), 7.53–7.62 (m, 2 H), 7.46 (t, J = 8.2 Hz, 2 H), 7.26–7.28 (m, 4 H), 7.14 (m, 2 H), 7.06 (t, J = 7.9 Hz, 1 H), 6.98 (d, J = 8.6 Hz, 2 H), 6.84 (d, J = 8.6 Hz, 1 H), 6.13 (dt, J = 9.0, 2.5 Hz, 2 H), 5.59 (s, 1 H), 4.94 (d, J = 15.3 Hz, 1 H), 4.77 (d, J = 15.7 Hz, 1 H), 3.93 (q, J = 7.4 Hz, 1 H), 1.34 (d, J = 7.0 Hz, 3 H). ¹³C NMR (99 MHz, CDCl₃): δ = 202.5, 176.8, 144.3, 142.4, 137.3, 135.5, 133.5, 131.6 (2C), 129.6, 128.8 (2C), 128.7 (2C), 128.2 (2C), 127.80, 127.75 (2C), 127.6, 126.2, 122.9, 118.9 (2C), 112.2, 109.7, 67.5, 45.1, 44.1, 13.0. IR (neat): 3341, 1715, 1593, 1486, 1465, 1343, 1259, 1211, 1173, 1075, 1001, 974 cm^–1. MS (ESI): m/z [M]⁺ calcd for [C₃₀H₂₅O₂N₂Br]⁺: 524.1094; found: 524.1084.
12 The use of a small amount of MeOH decreased the rate of methanolysis of silver amide 5, resulting low yield of the desired product 3, while an excess amount of MeOH accelerated protonation of the chiral silver enolate 4 and reduced the yield of 3.

Two examples of the synthesis of achiral silver alkoxides have been reported, see:

13a Edworthy IS, Rodden M, Mungur SA, Davis KM, Blake AJ, Wilson C, Schröder M, Arnold PL. J. Organomet. Chem. 2005; 690: 5710
13b Reisinger A, Himmel D, Krossing I. Angew. Chem. Int. Ed. 2006; 45: 6997

14 The relative and absolute stereochemistry of the Mannich products has not yet been determined.

Supplementary Material

Supporting Information