Synlett 2009(7): 1103-1106  
DOI: 10.1055/s-0028-1088158
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Regio- and Stereoselective Au(I)-Catalyzed Intermolecular Hydroalkoxylation of Aryl Allenes

Dong-Mei Cui*a, Ke-Rui Yua, Chen Zhang*b
a College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, P. R. of China
Fax: +86(571)88208459; e-Mail: cuidongmei@zjut.edu.cn;
b School of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, P. R. of China
Further Information

Publication History

Received 27 October 2008
Publication Date:
20 March 2009 (online)

Abstract

In the presence of a catalytic amount of Ph3PAuNO3 and H2SO4, the hydroalkoxylation of allenes with alcohols has been shown to proceed smoothly and give allylic ethers in good yields and high regio- and stereoselectivity.

9

Typical Experimental Procedure
To a reactor containing allene (0.5 mmol), Ph3PAuNO3 (0.01 mmol), and alcohol (0.6 mmol) was added H2SO4 (0.025 mmol). The mixture was then sealed and stirred at 40 ˚C for 4 h. It was quenched with sat. soln of NaHCO3 and then extracted with EtOAc (3 × 10 mL). The organic layer was washed with brine, dried over Na2SO4, and concentrated in vacuo. The residue was purified by flash chromatography to give the pure product.
( E )-1-Butyl-4-(3-methoxyprop-1-enyl)benzene (3i)
¹H NMR (500 MHz, CDCl3): δ = 7.30 (d, J = 8.5 Hz, 2 H), 7.12 (d, J = 8.5 Hz, 2 H), 6.57 (d, J = 16.0 Hz, 1 H), 6.23 (dt, J = 16.0, 6.0 Hz, 1 H), 4.07 (dd, J = 6.0, 1.5 Hz, 2 H), 3.37 (s, 3 H), 2.58 (t, J = 7.5 Hz, 2 H), 1.60-1.56 (m, 2 H), 1.37-1.32 (m, 2 H), 0.92 (t, J = 7.5 Hz, 3 H). ¹³C NMR (125 MHz, CDCl3): δ = 142.6, 134.1, 132.5, 128.6, 126.4, 124.9, 73.2, 57.9, 35.4, 33.5, 22.3, 13.9. IR: ν = 2950, 2929, 2958, 1635, 1512, 1456, 1384, 1191, 1119, 968, 847, 553 cm. HRMS: m/z calcd for C14H20O [M + 1+]; 205.1592; found: 205.1591.
( E )-1-Butyl-4-(3-ethoxyprop-1-enyl)benzene (3j)
¹H NMR (500 MHz, CDCl3): δ = 7.80 (d, J = 8.0 Hz, 2 H), 7.12 (d, J = 8.0 Hz, 2 H), 6.57 (d, J = 16.0 Hz, 1 H), 6.26 (dt, J = 16.0, 6.0 Hz, 1 H), 4.12 (dd, J = 6.0, 1.5 Hz, 2 H), 3.54 (q, J = 7.0 Hz, 2 H), 2.59 (t, J = 7.5 Hz, 2 H), 1.60-1.55 (m, 2 H), 1.39-1.30 (m, 2 H), 1.24 (t, J = 7.0 Hz, 3 H), 0.92 (t, J = 7.5 Hz, 3 H). ¹³C NMR (125 MHz, CDCl3): δ = 142.5, 134.2, 132.3, 128.6, 126.4, 125.3, 71.4, 65.6, 35.4, 33.6, 22.4, 15.3, 14.0. IR: ν = 2928, 1636, 1508, 1384, 1095, 526 cm. HRMS: m/z calcd for C15H22O [M+]: 218.1671; found: 218.1680. ( E )-1-Butyl-4-(3-isopropoxyprop-1-enyl)benzene (3k)
¹H NMR (500 MHz, CDCl3): δ = 7.29 (d, J = 8.0 Hz, 2 H), 7.11 (d, J = 8.0 Hz, 2 H), 6.55 (d, J = 16.0 Hz, 1 H), 6.26 (dt, J = 16.0, 6.5 Hz, 1 H), 4.12 (dd, J = 6.5, 1.5 Hz, 2 H), 3.71-3.63 (m, 1 H), 2.58 (t, J = 7.5 Hz, 2 H), 1.63-1.55 (m, 2 H), 1.37-1.30 (m, 2 H), 1.20 (d, J = 6.0 Hz, 6 H), 0.92 (t, J = 7.5 Hz, 3 H). ¹³C NMR (125 MHz, CDCl3): δ = 142.5, 134.4, 131.9, 128.7, 126.5, 126.0, 70.9, 69.0, 35.5, 33.7, 22.5, 22.3, 14.1. IR: ν = 2932, 1614, 1558, 1515, 1456, 1384, 1247, 1156, 1137, 1029, 810, 749, 551 cm. HRMS: m/z calcd for C16H24O [M+]: 232.1827; found: 232.1830. ( E )-1-(3- tert -Butoxyprop-1-enyl)-4-butylbenzene (3l)
¹H NMR (500 MHz, CDCl3): δ = 7.29 (d, J = 8.0 Hz, 2 H), 7.10 (d, J = 8.0 Hz, 2 H), 6.57 (d, J = 16.0 Hz, 1 H), 6.25 (dt, J = 16.0, 6.0 Hz, 1 H), 4.06 (dd, J = 6.0, 1.5 Hz, 2 H), 2.58 (t, J = 7.5 Hz, 2 H), 1.61-1.54 (m, 2 H), 1.36-1.31 (m, 2 H), 1.25 (s, 9 H), 0.92 (t, J = 7.5 Hz, 3 H). ¹³C NMR (125 MHz, CDCl3): δ = 142.2, 134.5, 131.2, 128.5, 126.6, 126.3, 73.3, 63.0, 35.4, 33.6, 27.7, 22.4, 14.0. IR: ν = 2958, 2929, 2858, 1681, 1625, 1512, 1457, 1384, 1194, 1122, 969, 525 cm. HRMS: m/z calcd for C17H26O [M+]: 246.1984; found: 246.1989.
( E )-1-(3-Methoxyprop-1-enyl)-4-pentylbenzene (3m)
¹H NMR (500 MHz, CDCl3): δ = 7.30 (d, J = 8.5 Hz, 2 H), 7.12 (d, J = 8.5 Hz, 2 H), 6.57 (d, J = 16.0 Hz, 1 H), 6.23 (dt, J = 16.0, 6.0 Hz, 1 H), 4.06 (dd, J = 6.0, 1.5 Hz, 2 H), 3.37 (s, 3 H), 2.57 (t, J = 7.5 Hz, 2 H), 1.63-1.56 (m, 2 H), 1.34-1.29 (m, 4 H), 0.88 (t, J = 7.0 Hz, 3 H). ¹³C NMR (125 MHz, CDCl3): δ = 142.6, 134.1, 132.5, 128.6, 126.4, 124.9, 73.2, 57.8, 35.6, 31.5, 31.1, 22.5, 14.0. IR: ν = 2927,2855, 1634, 1384, 1124, 544 cm. HRMS: m/z calcd for C15H22O [M+]: 218.1671; found: 218.1665.
( E )-1-(3-Ethoxyprop-1-enyl)-4-pentylbenzene (3n)
¹H NMR (500 MHz, CDCl3): δ = 7.29 (d, J = 8.0 Hz, 2 H), 7.10 (d, J = 8.0 Hz, 2 H), 6.57 (d, J = 16.0 Hz, 1 H), 6.25 (dt, J = 16.0, 6.0 Hz, 1 H), 4.11 (dd, J = 6.0, 1.5 Hz, 2 H), 3.53 (q, J = 7.0 Hz, 2 H), 2.57 (t, J = 7.5 Hz, 2 H), 1.63-1.56 (m, 2 H), 1.33-1.30 (m, 4 H), 1.24 (t, J = 7.0 Hz, 3 H), 0.88 (t, J = 7.0 Hz, 3 H). ¹³C NMR (125 MHz, CDCl3): δ = 142.5, 134.2, 132.2, 128.6, 126.4, 125.3, 71.3, 65.6, 35.6, 31.5, 31.1, 22.5, 15.2, 14.0. IR: ν = 2950, 2927, 2855, 1652, 1558, 1506, 1456, 1384, 1100, 968, 539 cm. HRMS: m/z calcd for C16H24O [M+]: 232.1831; found: 232.1827.

( E )-1-(3-Isopropoxyprop-1-enyl)-4-pentylbenzene (3o)
¹H NMR (500 MHz, CDCl3): δ = 7.29 (d, J = 8.0 Hz, 2 H), 7.11 (d, J = 8.0 Hz, 2 H), 6.57 (d, J = 15.5 Hz, 1 H), 6.25 (dt, J = 15.5, 6.0 Hz, 1 H), 4.12 (dd, J = 6.0, 1.5 Hz, 2 H), 3.71-3.65 (m, 1 H), 2.57 (t, J = 7.5 Hz, 2 H), 1.63-1.56 (m, 2 H), 1.34-1.29 (m, 4 H), 1.20 (d, J = 6.0 Hz, 6 H), 0.88 (t, J = 7.0 Hz, 3 H). ¹³C NMR (125 MHz, CDCl3): δ = 142.4, 134.3, 131.8, 128.5, 126.4, 125.8, 70.8, 68.8, 35.6, 31.5, 31.1, 22.5, 22.1, 14.0. IR: ν = 2950, 2927, 2856, 1633, 1384, 1123, 1070, 965, 544 cm. HRMS: m/z calcd for C17H26O [M+]: 246.1984; found: 246.1981.
( E )-1-(3-Isopropoxyprop-1-enyl)-4-methoxybenzene (3r)
¹H NMR (500 MHz, CDCl3): δ = 7.33-7.31 (m, 2 H), 6.85-6.83 (m, 2 H), 6.54 (d, J = 15.5 Hz, 1 H), 6.17 (dt, J = 15.5, 6.0 Hz,1 H), 4.11 (dd, J = 6.0, 1.5 Hz, 2 H), 3.80 (s, 3 H), 3.71-3.65 (m, 1 H), 1.20 (d, J = 6.0 Hz, 6 H). ¹³C NMR (125 MHz, CDCl3): δ = 159.2, 131.5, 129.7, 127.6, 124.6, 113.9, 70.8, 68.9, 55.3, 22.2. IR: ν = 2872, 1634, 1558, 1491, 1407, 1384, 1088, 1038, 1013, 937, 804, 485 cm. HRMS: m/z calcd for C13H18O [M + 1+]: 207.1385; found: 207.1385.


( E )-1-(3-Ethoxyprop-1-enyl)-3-fluorobenzene (3u)
¹H NMR (500 MHz, CDCl3): δ = 7.28-7.24 (m, 1 H), 7.15-7.13 (m, 1 H), 7.10-7.06 (m, 1 H), 6.94-6.90 (m, 1 H), 6.58 (d, J = 16.0 Hz, 1 H), 6.30 (dt, J = 16.0, 6.0 Hz, 1 H), 4.14 (dd, J = 6.0, 1.5 Hz, 2 H), 3.56 (q, J = 7.0 Hz, 2 H), 1.25 (t, J = 7.0 Hz, 3 H). ¹³C NMR (125 MHz, CDCl3): δ = 163.1 (d, J = 243.8 Hz), 139.2 (d, J = 8.8 Hz), 130.8, 129.9 (d, J = 8.8 Hz), 127.8, 122.3, 114.3 (d, J = 21.3 Hz), 112.9 (d, J = 21.3 Hz), 70.9, 65.9, 15.2. IR: ν = 2995, 1770, 1759, 1635, 1834, 1246, 1058, 913, 743, 526 cm. HRMS: m/z calcd for C11H13FO [M+]: 180.0950; found: 180.0946. ( E )-1-Bromo-3,4-dimethoxy-2-(3-methoxybut-1-enyl)-benzene (3v) ¹H NMR (500MHz, CDCl3): δ = 7.29 (d, J = 8.5 Hz, 2 H), 6.70 (d, J = 8.5 Hz, 2 H), 6.48 (d, J = 16.0 Hz, 1 H), 6.14 (dd, J = 16.0, 7.5 Hz, 1 H), 3.95-3.90 (m, 1 H), 3.86 (s, 3 H), 3.75 (s, 3 H), 3.38 (s, 3 H), 1.36 (dd, J = 6.5, 2.5 Hz, 3 H). ¹³C NMR (125 MHz, CDCl3): δ = 152.6, 148.1, 138.8, 131.2, 128.1, 125.9, 114.6, 112.1, 78.7, 60.1, 56.2, 56.0, 21.6. IR: ν = 2928, 1636, 1508, 1384, 1095, 526 cm. HRMS: m/z calcd for C13H17BrO3 [M+]: 300.0361; found: 300.0341.