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 2013; 24(5): 635-639
DOI: 10.1055/s-0032-1318306
DOI: 10.1055/s-0032-1318306
letter
α-Selective Allylation of Azo Compounds Using Allylic Barium Reagents
Weitere Informationen
Publikationsverlauf
Received: 26. Dezember 2012
Accepted after revision: 01. Februar 2013
Publikationsdatum:
27. Februar 2013 (online)
![](https://www.thieme-connect.de/media/synlett/201305/lookinside/thumbnails/10.1055-s-0032-1318306-1.jpg)
Abstract
The addition of allylic barium reagents to azo compounds was achieved with high α-regioselectivity. The double-bond geometry of allylic barium reagents was retained throughout the reaction at –78 °C and E- or Z-enriched allylic hydrazines were selectively obtained from the corresponding allylic barium reagents. An allylic hydrazine was efficiently converted into an allylic amine by reductive N–N bond cleavage.
-
References and Notes
- 1a Sell MS, Rieke RD. Synth. Commun. 1995; 25: 4107
- 1b Rieke RD, Sell MS, Klein WR, Chen T.-A, Brown JD, Hanson MV In Active Metals. Preparation, Characterization, Applications . Fürstner A. VCH; Weinheim: 1996: 1
- 1c Rieke RD, Hanson MV. Tetrahedron 1997; 53: 1925
- 2a Yanagisawa A, Habaue S, Yamamoto H. J. Am. Chem. Soc. 1991; 113: 8955
- 2b Yanagisawa A, Habaue S, Yasue K, Yamamoto H. J. Am. Chem. Soc. 1994; 116: 6130
- 2c Yanagisawa A, Yamamoto H In Active Metals. Preparation, Characterization, Applications . Fürstner A. VCH; Weinheim: 1996: 61
- 2d Yanagisawa A In Science of Synthesis . Vol. 7. Yamamoto H. Thieme; Stuttgart: 2004: 695
- 2e Yanagisawa A In Main Group Metals in Organic Synthesis . Vol. 1. Yamamoto H, Oshima K. Wiley-VCH; Weinheim: 2004: 175
- 2f Miyoshi N, Kamiura K, Oka H, Kita A, Kuwata R, Ikehara D, Wada M. Bull. Chem. Soc. Jpn. 2004; 77: 341
- 2g Miyoshi N, Ikehara D, Kohno T, Matsui A, Wada M. Chem. Lett. 2005; 34: 760
- 2h Miyoshi N In Science of Synthesis . Vol. 7. Yamamoto H. Thieme; Stuttgart: 2004: 685
- 2i Miyoshi N, Ikehara D, Matsuo T, Kohno T, Matsui A, Wada M. J. Synth. Org. Chem., Jpn. 2006; 64: 845
- 3 Yanagisawa A, Koide T, Yoshida K. Synlett 2010; 1515
- 4a Rutjes FP. J. T, Hiemstra H, Mooiweer HH, Speckamp WN. Tetrahedron Lett. 1988; 29: 6975
- 4b Yamamoto Y, Yumoto M, Yamada J. Tetrahedron Lett. 1991; 32: 3079
- 4c Kano N, Yamamura M, Kawashima T. J. Am. Chem. Soc. 2004; 126: 6250
- 4d Yamamura M, Kano N, Kawashima T. J. Organomet. Chem. 2007; 692: 313
- 4e De Matteis V, van Delft FL, Tiebes J, Rutjes FP. J. T. Synlett 2008; 351
- 4f Klimenko IP, Medvedev AF, Korolev VA, Kolomnikova GD, Tomilov YV, Bubnov YN. J. Organomet. Chem. 2009; 694: 2106
- 5a Rabjohn N. J. Am. Chem. Soc. 1948; 70: 1181
- 5b Brimble MA, Heathcock CH. J. Org. Chem. 1993; 58: 5261
- 5c Künneth R, Feldmer C, Knoch F, Kisch H. Chem. Eur. J. 1995; 1: 441
- 5d Magnus P, Garizi N, Seibert KA, Ornholt A. Org. Lett. 2009; 11: 5646
- 6 Brown MJ, Clarkson GJ, Inglis GG, Shipman M. Org. Lett. 2011; 13: 1686
- 7 For a review of reductive N–N bond cleavage of hydrazines, see: Gilchrist TL. In Comprehensive Organic Synthesis . Vol. 8. Trost BM, Fleming I. Pergamon; Oxford: 1991: 388
- 8 Zhang Y, Tang Q, Luo M. Org. Biomol. Chem. 2011; 9: 4977
- 9 Kaupp M, Schleyer P.v.R. J. Am. Chem. Soc. 1992; 114: 491
- 10 Carreira and co-workers have reported that the cobalt-catalyzed hydrohydrazination of dienes provided allylic hydrazines with good regioselectivity, see: Waser J, González-Gómez JC, Nambu H, Huber P, Carreira EM. Org. Lett. 2005; 7: 4249
- 11 α-Selective Allylation: Synthesis of (E)-1-(3,7-Dimethylocta-2,6-dien-1-yl)-1,2-diphenylhydrazine (Scheme 2 and Table 2, Entry 2); Typical Procedure: To a solution of biphenyl (370 mg, 2.4 mmol) in anhydrous THF (5 mL) was added freshly cut lithium (16.7 mg, 2.4 mmol). Stirring the mixture at r.t. for 2 h gave a dark-blue lithium biphenylide solution. Anhydrous BaI2 (470 mg, 1.2 mmol) was placed in a separate flask, and this was covered with anhydrous THF (5 mL) and stirred at r.t. for 20 min. To the solution of BaI2 in THF was added at r.t. a solution of lithium biphenylide in THF under an argon stream. The reaction mixture was stirred at r.t. for 20 min, then to the resulting dark-brown suspension of reactive barium (1.2 mmol) in THF (10 mL) was added a solution of geranyl chloride (0.185 mL, 1.0 mmol) in THF (2 mL) at –78 °C by syringe pump (6 mL/h). After stirring for 20 min, the mixture was treated with a solution of azobenzene (91.1 mg, 0.5 mmol) in THF (2 mL) at –78 °C (slow addition at 6 mL/h) and stirred for 10 min at this temperature. To the mixture was added sat. aq NH4Cl (5 mL), and the aqueous layer was extracted with Et2O (3 × 10 mL). The combined organic extracts were washed with sodium thiosulfate (10% w/v) and brine, dried over Na2SO4, and concentrated in vacuo after filtration. The residual crude product was purified by column chromatography on silica gel (hexane–EtOAc, 20:1 then 80:1) to afford the allylic hydrazine. The chemical yield was determined to be 77% by 1H NMR spectroscopic analysis using 1,4-bis(trimethylsilyl)benzene as an internal standard, and the α/γ and E/Z ratios were determined to be >99:1 and 99:1, respectively, by 1H NMR and HPLC analyses. 1H NMR (500 MHz, CDCl3): δ = 7.26–7.20 (m, 2 H, ArH), 7.01 (dd, J = 7.7, 1.0 Hz, 2 H, ArH), 6.84–6.79 (m, 4 H, ArH), 5.57 (br s, 1 H, NH), 5.28 (dt, J = 1.5, 6.8 Hz, 1 H, CH), 5.03 (tt, J = 8.0, 1.4 Hz, 1 H, CH), 4.10 (br s, 2 H, CH), 2.11–2.00 (m, 4 H, CH), 1.68 (d, J = 0.8 Hz, 3 H, CH), 1.59 (s, 3 H, CH), 1.58 (d, J = 0.85 Hz, 3 H, CH); 13C NMR (125 MHz, CDCl3): δ = 150.2, 147.8, 141.3, 131.8, 129.3 (2C), 129.1 (2C), 123.9, 119.7, 118.7, 117.8, 113.5 (2C), 112.9 (2C), 48.1, 39.6, 26.3, 25.7, 17.7, 16.2; IR (neat): 3321, 2965, 2922, 1600, 1495, 1596, 1254, 749, 692 cm–1; HRMS (ESI): m/z [M + H]+ calcd for [C22H29N2]+: 321.2325; found: 321.2322.
For reviews, see:
For reactions of allylic barium reagents, see:
For reviews, see:
For related strontium reagents, see: