RSS-Feed abonnieren
Bitte kopieren Sie die angezeigte URL und fügen sie dann in Ihren RSS-Reader ein.
https://www.thieme-connect.de/rss/thieme/de/10.1055-s-00000083.xml
Synlett 2015; 26(11): 1638-1641
DOI: 10.1055/s-0034-1381012
DOI: 10.1055/s-0034-1381012
letter
Chiral Imidazolinium Salts with TIPS Groups for the Palladium-Catalyzed α-Arylation and as Chiral Solvating Agents
Weitere Informationen
Publikationsverlauf
Received: 07. März 2015
Accepted after revision: 16. Juni 2015
Publikationsdatum:
18. Juni 2015 (online)
![](https://www.thieme-connect.de/media/synlett/201511/lookinside/thumbnails/st-2015-b0165-l_10-1055_s-0034-1381012-1.jpg)
Dedicated to Peter Vollhardt on the occasion of his 69th birthday
Abstract
The synthesis of imidazolinium salts from low-cost amino alcohols incorporating different sterically demanding silyl groups is described. The new salts were analyzed and investigated as carbene precursors in a palladium-catalyzed asymmetric intramolecular α-arylation of an amide. The easily accessible carbene precursors gave enantiomeric excesses of up to 72% with nearly quantitative yields. The salts were also successfully applied as chiral solvating agents with the potassium salt of Mosher’s carboxylate and can therefore contribute to the field of chiral recognition.
Supporting Information
- Supporting information for this article is available online at http://dx.doi.org/10.1055/s-0034-1381012.
- Supporting Information
-
References and Notes
- 1 Current address: COMSATS Institute of Information Technology, Defence Road, Off Raiwind Road, Lahore, Pakistan.
-
2 Herrmann WA. Angew. Chem. Int. Ed. 2002; 41: 1290
-
3 Bourissou D, Guerret O, Gabbai FP, Bertrand G. Chem. Rev. 2000; 100: 39
- 4 Perry MC, Burgess K. Tetrahedron: Asymmetry 2003; 14: 951
- 5 Cesar V, Bellemin-Laponnaz S, Gade LH. Chem. Soc. Rev. 2004; 33: 619
- 6 Kantchev EA. B, O’Brien CJ, Organ MG. Angew. Chem. Int. Ed. 2007; 46: 2768
- 7 N-Heterocyclic Carbenes in Synthesis . Nolan SP. Wiley-VCH; Weinheim: 2006
-
8 Benhamou L, Chardon E, Lavigne G, Bellemin-Laponnaz S, César V. Chem. Rev. 2011; 111: 2705
-
9 Lee S, Hartwig JF. J. Org. Chem. 2001; 66: 3402
- 10 Baskakov D, Herrmann WA, Herdtweck E, Hoffmann SD. Organometallics 2007; 26: 626
- 11 Glorius F, Altenhoff G, Goddard R, Lehmann C. Chem. Commun. 2002; 2704
-
12 Ma YD, Song C, Ma CQ, Sun ZJ, Chai Q, Andrus MB. Angew. Chem. Int. Ed. 2003; 42: 5871
- 13 Fürstner A, Alcarazo M, Krause H, Lehmann CW. J. Am. Chem. Soc. 2007; 129: 12676
- 14 Jurcik V, Gilani MA, Wilhelm R. Eur. J. Org. Chem. 2006; 5103
- 15 Gilani MA, Wilhelm R. Tetrahedron: Asymmetry 2008; 19: 2346
-
16 Larsen AO, Leu W, Oberhuber CN, Campbell JE, Hoveyda AH. J. Am. Chem. Soc. 2004; 126: 11130
- 17 Arnold PL, Scarisbrick AC, Blake AJ, Wilson C. Chem. Commun. 2001; 2340
- 18 Martin D, Kehrli S, d’Augustin M, Clavier H, Mauduit M, Alexakis A. J. Am. Chem. Soc. 2006; 128: 8416
-
19 Arao T, Kondo K, Aoyama T. Tetrahedron Lett. 2006; 47: 1417
-
20 Kündig EP, Seidel TM, Jia YX, Bernardinelli G. Angew. Chem. Int. Ed. 2007; 46: 8484
-
21 Luan XJ, Mariz R, Robert C, Gatti M, Blumentritt S, Linden A, Dorta R. Org. Lett. 2008; 10: 5569
-
22 Würtz S, Lohre C, Fröhlich R, Bergander K, Glorius F. J. Am. Chem. Soc. 2009; 131: 8344
- 23 Jia Y.-X, Katayev D, Bernardinelli G, Seidel TM, Kündig EP. Chem. Eur. J. 2010; 16: 6300
-
24 Liu L, Ishida N, Ashida S, Murakami M. Org. Lett. 2011; 13: 1666
-
25 Spallek MJ, Riedel D, Rominger F, Hashmi AS. K, Trapp O. Organometallics 2012; 31: 1127
- 26 Winkel A, Reddy PV. G, Wilhelm R. Synthesis 2008; 999
- 27 General Procedure for the Preparation of Imidazolinium SaltsA protected bishydroxy amine (1 mmol) was placed into a pressure vessel. NH4BF4 (1 mmol, 1.04 g) was added, and the vessel was flushed with nitrogen. Triethyl orthoformate (1 mmol, 1.65 mL) was added, and the vessel was sealed. The mixture was heated to 120 °C for the indicated time. Thereafter, the crude solid was either recrystallized from dry EtOH or purified via column chromatography (CH2Cl2–MeOH, 20:1). Compound 9 was prepared from 1, NH4BF4, and triethyl orthoformate as a yellow solid (0.65 mmol, 0.422 g, 65%); mp 82 °C. [α]D 22 –30 (c 0.52, MeOH). IR (KBr): νmax = 3423, 2946, 2868, 1646, 1464, 1261, 1098, 882, 818, 706, 682 cm–1. 1H NMR (200 MHz, CDCl3): δ = 7.42–7.24 (m, 11 H, ArH, NCHN), 4.72 (d, J = 3.6 Hz, 2 H, CHOTIPS), 4.00–3.15 [m, 6 H, NCH, N(CH2 )2N], 0.96–0.85 (m, 48 H, TIPSH, NCHCH3 ). 13C NMR (50 MHz, CDCl3): δ = 156.8, 139.1, 128.9, 128.5, 127.2, 77.9, 61.2, 48.5, 18.1, 18.0, 15.0, 12.2. ESI-MS: m/z = 651.5 (100) [M+]. ESI-HRMS: m/z calcd for C39H67N2O2Si2 [M]+: 651.4741; found: 651.4745.
- 28 Arnold PL, Casely IJ, Turner ZR, Carmichael CD. Chem. Eur. J. 2008; 14: 10415