Synlett 2005(6): 1000-1002  
DOI: 10.1055/s-2005-864822
LETTER
© Georg Thieme Verlag Stuttgart · New York

Single-Step Stereoselective Synthesis of (E)- and (Z)-Allylamines from Acetyl Derivatives of Baylis-Hillman Adducts [1]

Biswanath Das*, Gurram Mahender, Nikhil Chowdhury, Joydeep Banerjee
Organic Chemistry Division - I, Indian Institute of Chemical Technology, Hyderabad - 500 007, India
Fax: +91(40)7160512; e-Mail: biswanathdas@yahoo.com;
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Publikationsverlauf

Received 22 November 2004
Publikationsdatum:
23. März 2005 (online)

Abstract

Stereoselective synthesis of (E)- and (Z)-allylamines has been achieved in a single-step by treatment of the acetyl derivatives of Baylis-Hillman adducts with ammonium acetate in anhydrous methanol at room temperature. The reaction proceeded under neutral conditions to form the corresponding allylamines in high yields and stereoselectivity.

1

Part 56 in the series, ‘Studies on Novel Synthetic Methodologies’. IICT Communication No. 050216

1

Part 56 in the series, ‘Studies on Novel Synthetic Methodologies’. IICT Communication No. 050216

8

General Procedure for the Preparation of Allylamines.
To a solution of 1 or 2 (1 mmol) in anhyd MeOH (10 mL), NH4OAc (8 equiv) was added in one portion under a nitrogen atmosphere. The mixture was stirred at r.t. and monitored by TLC. After completion, the solution was concentrated and dissolved in CH2Cl2 (10 mL). The solution was washed with brine (3 × 10 mL) followed by H2O (3 × 10 mL) and the combined aqueous washings extracted with CH2Cl2 (3 × 10 mL). The total CH2Cl2 portion was concentrated and subjected to column chromatography over silica gel using EtOAc-hexane (1:4) as eluent to afford pure allylamine (3 or 4). The spectroscopic and analytical data of some representative allylamines (major product) are given below.
Compound 3b: IR (KBr): νmax = 3452, 1722, 1526, 1482 cm-1. 1H NMR (200 MHz, CDCl3): δ = 7.92 (1 H, s), 7.46 (1 H, dd, J = 8.0, 2.0 Hz), 7.34 (1 H, dd, J = 8.0, 2.0 Hz), 7.22 (1 H, td, J = 8.0, 2.0 Hz), 7.12 (1 H, td, J = 8.0, 2.0 Hz), 3.74 (3 H, s), 3.10 (2 H, s). 13C NMR (50 MHz, CDCl3): δ = 168.4, 139.7, 134.0, 133.5, 131.6, 131.2, 129.8, 129.4, 126.6, 52.0, 49.6. EIMS: m/z = 225, 227 [M+]. Anal. Calcd for C11H12ClNO2 (%): C, 58.54; H, 5.32; N, 6.21. Found: C, 58.62; H, 5.29; N, 6.28.
Compound 3d: IR (KBr): νmax = 3462, 1723, 1585, 1505 cm-1. 1H NMR (200 MHz, CDCl3): δ = 8.40 (1 H, t, J = 2.0 Hz), 8.18 (1 H, dt, J = 8.0, 2.0 Hz), 7.82 (1 H, dt, J = 8.0, 2.0 Hz), 7.80 (1 H, s), 7.54 (1 H, t, J = 8.0 Hz), 3.83 (3 H, s), 3.54 (2 H, s). 13C NMR (50 MHz, CDCl3): δ = 167.8, 148.3, 140.0, 136.4, 135.6, 129.6, 135.3, 124.3, 123.4, 52.2, 50.1. MS (EI): m/z = 236 [M+]. Anal. Calcd for C11H12N2O4 (%): C, 55.93; H, 5.08; N, 11.86. Found: C, 55.88; H, 5.01; N, 11.84.
Compound 3e: IR (KBr): νmax = 3440, 1732, 1560, 1522 cm-1. 1H NMR (200 MHz, CDCl3): δ = 6.89 (1 H, t, J = 7.0 Hz), 3.64 (3 H, s), 3.08 (2 H, s), 2.09 (2 H, t, J = 7.0 Hz), 1.72 (1 H, m), 0.92 (6 H, d, J = 7.0 Hz). MS (EI): m/z = 171 [M+]. Anal. Calcd for C9H17NO2 (%): C, 63.17; H, 15.74; N, 12.96. Found: C, 63.24; H, 15.81; N, 12.85.
Compound 4a: IR (KBr): νmax = 3453, 2354, 1620, 1532 cm-1. 1H NMR (200 MHz, CDCl3): δ = 7.72-7.67 (2 H, m), 7.40-7.28 (3 H, m), 7.07 (1 H, s), 3.56 (2 H, s). 13C NMR (50 MHz, CDCl3): δ = 137.2, 130.5, 129.9, 129.4, 128.6, 128.3, 126.2, 118.8, 116.5, 52.0. MS (EI): m/z = 158 [M+]. Anal. Calcd for C10H10N (%): C, 83.33; H, 6.94; N, 19.44. Found: C, 83.41; H, 6.88; N, 19.40.
Compound 4c: IR (KBr): νmax = 3442, 2352, 1522, 1485 cm-1. 1H NMR (200 MHz, CDCl3): δ = 7.72 (2 H, d, J = 8.0 Hz), 7.43 (2 H, d, J = 8.0 Hz), 7.10 (1 H, s), 3.62 (2 H, s). MS (EI): m/z = 192, 194 [M+]. Anal. Calcd for C10H9ClN2 (%): C, 62.34; H, 4.68; N, 14.55. Found: C, 62.41; H, 4.71; N, 14.51.