Page 7 of 10
The Journal of Organic Chemistry
2H), 6.89 (d, J = 8.4 Hz, 2H), 3.82 (s, 3H), 1.33 (s, 12H). 13C NMR
(d, J = 8.4 Hz, 2H), 7.34 (d, J = 8.4 Hz, 2H), 1.34 (s, 12H). 13C
1
2
3
4
5
6
7
8
(100 MHz, CDCl3) δ 162.2, 136.5, 113.3, 83.6, 55.1, 24.9.16
NMR (100 MHz, CDCl3) δ 137.7, 136.3, 128.2, 84.2, 25.0. 5a
2-(3-Methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
(4l). This compound was prepared according to General Procedure
1 for 12 h and was purified on silica gel chromatography
(petroleum ether/CH2Cl2/EtOAc = 100:1:1) to afford a colorless
oil, 72.3 mg, 62%. 1H NMR (400 MHz, CDCl3) δ 7.40 (d, J = 7.6
Hz, 1H), 7.33–7.25 (m, 2H), 7.00 (dd, J = 8.4, 2.4 Hz, 1H), 3.83 (s,
3H), 1.34 (s, 12H). 13C NMR (100 MHz, CDCl3) δ 159.2, 129.1,
127.3, 118.9, 118.0, 84.0, 55.4, 25.0. 18
4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)phenol
(4d).
This compound was prepared according to General Procedure 1 for
24 h and was purified on silica gel chromatography (petroleum
ether/CH2Cl2/EtOAc = 20:1:1) to afford a yellow solid, 77.5 mg,
70%, mp 110−111 °C. 1H NMR (400 MHz, CDCl3) δ 7.70 (d, J =
8.4 Hz, 2H), 6.82 (d, J = 8.4 Hz, 2H), 5.68 (brs, 1H), 1.33 (s, 12H).
13C NMR (100 MHz, CDCl3) δ 158.5, 136.7, 114.9, 83.7, 24.6.5a
N,N-Dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)aniline (4e). This compound was prepared according to General
Procedure 1 for 24 h and was purified on silica gel chromatography
(petroleum ether/CH2Cl2/EtOAc = 100:1:1) to afford a white solid,
67.5 mg, 55%, mp 119−120 °C. 1H NMR (400 MHz, CDCl3) δ 7.69
(d, J = 8.4 Hz, 2H), 6.69 (d, J = 8.4 Hz, 2H), 2.98 (s, 6H), 1.32 (s,
12H). 13C NMR (100 MHz, CDCl3) δ 152.6, 136.2, 111.3, 83.2,
40.1, 24.8.5a
Tert-butyl
4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
9
yl)benzoate (4m). This compound was prepared according to
General Procedure 1 for 24 h and was purified on silica gel
chromatography (petroleum ether/CH2Cl2/EtOAc = 100:1:1) to
afford a yellow oil, 73.7 mg, 48%. 1H NMR (400 MHz, CDCl3) δ
7.95 (d, J = 7.6 Hz, 2H), 7.83(d, J = 7.6 Hz, 2H), 1.59 (s, 9H), 1.35
(s, 12H). 13C NMR (100 MHz, CDCl3) δ 165.8, 134.5, 134.2, 128.4,
84.1, 81.1, 28.2, 24.9.5a
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
2-([1,1'-Biphenyl]-4-yl)-4,4,5,5-tetramethyl-1,3,2-
dioxaborolane (4f). This compound was prepared according to
General Procedure 1 for 12 h and was purified on silica gel
chromatography (petroleum ether/CH2Cl2/EtOAc = 100:1:1) to
4,4,5,5-Tetramethyl-2-(4-(trifluoromethyl)phenyl)-1,3,2-
dioxaborolane (4n). This compound was prepared according to
General Procedure 1 for 12 h and was purified on silica gel
chromatography (petroleum ether/CH2Cl2/EtOAc = 100:1:1) to
afford a yellow solid, 42.5 mg, 31%, mp 72−73 °C. 1H NMR (400
MHz, CDCl3) δ 7.91 (d, J = 7.6 Hz. 2H), 7.61 (d, J = 7.6 Hz, 2H),
1.36 (s, 12H). 13C NMR (100 MHz, CDCl3) δ 135.0, 133.0, 132.7,
129.4, 126.1, 124.3 (q, J = 3.8 Hz), 122.8, 84.3, 24.8.16
(4,4,5,5-tetramethyl-2-(p-tolyl)-1,3,2-dioxaborolane (4o). This
compound was prepared according to General Procedure 1 for 12 h
and was purified on silica gel chromatography (petroleum
ether/CH2Cl2/EtOAc = 100:1:1) to afford a yellow oil, 75.3 mg,
69%. 1H NMR (400 MHz, CDCl3) δ 7.70 (d, J = 8.0, 2H), 7.18 (d,
J = 8.0, 2H), 2.36 (s, 3H), 1.33 (s, 12H). 13C NMR (100 MHz,
CDCl3) δ 141.4, 134.8, 128.6, 83.6, 24.9, 21.7.5a
2-(4-Butoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
(4p). This compound was prepared according to General Procedure
1 for 12 h and was purified on silica gel chromatography
(petroleum ether/CH2Cl2/EtOAc = 100:1:1) to afford a colorless
oil, 75.7 mg, 55%. 1H NMR (400 MHz, CDCl3) δ 7.74 (d, J = 8.4
Hz, 2H), 6.89 (d, J = 8.0 Hz, 2H), 3.99 (t, J = 6.8 Hz, 2H), 1.80-
1.73 (m, 2H), 1.54-1.44 (m, 2H), 1.33 (s, 12H), 0.97 (t, J = 7.6 Hz,
3H). 13C NMR (100 MHz, CDCl3) δ 161.9, 136.6, 114.0, 83.6, 67.6,
31.4, 25.0, 19.4, 14.0.16
4,4,5,5-Tetramethyl-2-(naphthalen-2-yl)-1,3,2-dioxaborolane
(4r). This compound was prepared according to General Procedure
1 for 12 h and was purified on silica gel chromatography
(petroleum ether/CH2Cl2/EtOAc = 100:1:1) to afford a white solid,
59.5 mg, 47%, mp 55−56 °C. 1H NMR (400 MHz, CDCl3) δ 8.38
(s, 1H), 7.89 (d, J = 8.0 Hz, 1H), 7.86–7.83 (m, 3H), 7.53-7.46 (m,
2H), 1. 40 (s, 12H). 13C NMR (100 MHz, CDCl3) δ 136.4, 135.2,
133.0, 130.6, 128.8, 127.9, 127.1 (two peaks), 125.9, 84.1, 25.1. 18
General procedure for dehalogenation of Aryl Halides
(General Procedure 2). tBuOK (1.0 moml, 112 mg) was weighed
directly into a Schlenk tube and dried under high vacuum for 15
min. Then DMF (1 mL), 1, and PhCHO(52 μL) were added and
stirred at 90 °C and the reaction was monitored by TLC. The
reaction mixture was purified on silica gel chromatography
(EtOAc/petroleum ether as eluent) to give the product.
1
afford a yellow solid, 93.1 mg, 67%, mp 111−112 °C. H NMR
(400 MHz, CDCl3) δ 7.89 (d, J = 8.0 Hz, 2H), 7.61 (dd, J = 8.0, 1.6
Hz, 4H), 7.45-7.42 (m, 2H), 7.37-7.33(m, 1H), 1.36 (s, 12H). 13C
NMR (100 MHz, CDCl3) δ 143.9, 141.1, 135.3, 128.8, 127.6,
127.3, 126.5, 83.8, 24.9.16
4,4,5,5-Tetramethyl-2-(naphthalen-1-yl)-1,3,2-dioxaborolane
(4g). This compound was prepared according to General Procedure
1 for 12 h and was purified on silica gel chromatography
(petroleum ether/CH2Cl2/EtOAc = 100:1:1) to afford a yellow
solid, 92.5 mg, 73%, mp 52−53 °C. 1H NMR (400 MHz, CDCl3) δ
8.76 (d, J = 8.0 Hz, 1H), 8.08 (dd, J = 6.8, 1.2 Hz, 1H), 7.93 (d, J
= 8.0 Hz, 1H), 7.83 (d, J = 8.0 Hz, 1H), 7.55-7.51 (m, 1H), 7.47
(dd, J = 15.8, 7.0 Hz, 2H), 1.42 (s, 12H). 13C NMR (100 MHz,
CDCl3) δ 137.0, 135.7, 133.2, 131.6, 128.4 (two peak), 126.3,
125.5, 125.0, 83.7, 25.0.17
(1-Methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-
indole (4h). This compound was prepared according to General
Procedure 1 for 30 h and was purified on silica gel chromatography
(petroleum ether/CH2Cl2/EtOAc = 100:1:1) to afford a yellow
1
solid, 62 mg, 48%, mp 98−99 °C. H NMR (400 MHz, CDCl3) δ
8.16 (s, 1H), 7.66 (d, J = 8.0 Hz, 1H), 7.32 (d, J = 8.0 Hz, 1H), 7.03
(d, J = 3.0 Hz, 1H), 6.50 (d, J = 3.0 Hz, 1H). 3.79 (s, 3H), 1.37 (s,
12H). 13C NMR (100 MHz, CDCl3) δ 138.6, 128.9, 128.8, 128.2,
127.6, 108.6, 101.7, 83.4, 32.8, 25.0.5a
2-(4-Fluorophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
(4i). This compound was prepared according to General Procedure
1 for 12 h and was purified on silica gel chromatography
(petroleum ether/CH2Cl2/EtOAc = 100:1:1) to afford a yellow oil,
78.6 mg, 71%. 1H NMR (400 MHz, CDCl3) δ 7.80 (dd, J = 8.4, 6.4
Hz, 2H), 7.05 (t, J = 9.0 Hz, 2H), 1.34 (s, 12H). 13C NMR (100
MHz, CDCl3) δ 166.4, 163.8, 137.0 (d, J = 7.8 Hz), 114.8 (d, J =
20 Hz), 83.9, 24.7.5a
2-(4-(tert-Butyl)phenyl)-4,4,5,5-tetramethyl-1,3,2-
dioxaborolane (4j). This compound was prepared according to
General Procedure 1 for 12 h and was purified on silica gel
chromatography (petroleum ether/CH2Cl2/EtOAc = 100:1:1) to
afford a colorless oil, 81.7 mg, 63%. 1H NMR (400 MHz, CDCl3)
δ 7.78 (d, J = 8.4 Hz, 2H), 7.42 (d, J = 8.4 Hz, 2H), 1.35 (s, 12H),
1.34 (s, 9H). 13C NMR (100 MHz, CDCl3) δ 154.6, 134.9, 124.8,
83.7, 35.0, 31.3, 25.0. 18
2-(4-Chlorophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
(4k). This compound was prepared according to General Procedure
1 for 12 h and was purified on silica gel chromatography
(petroleum ether/CH2Cl2/EtOAc = 100:1:1) to afford a white solid,
38.3 mg, 32%, mp 50−51 °C. 1H NMR (400 MHz, CDCl3) δ 7.73
5a, 5c, 5d, 5g, 5i-5r were prepared according to General
Procedure 2. Yields were determined by GC using mesitylene (69
μL) as internal standard. The structure was confirmed by standard
benzene sample by GC.
N,N-Dimethylaniline (5e). This compound was prepared
according to General Procedure 2 for 2 h and was purified on silica
gel chromatography (petroleum ether/CH2Cl2/EtOAc = 20:1:1) to
1
afford a yellow oil, 55 mg, 91%. H NMR (400 MHz, CDCl3) δ
7.26-7.22 (m, 2H), 6.26-6.70 (m, 3H), 2,93 (s, 6H). 13C NMR (100
MHz, CDCl3) δ 150.7, 129.1, 116.7, 112.7, 40.7. 8c
ACS Paragon Plus Environment