Cyclopalladated Ferrocenylimine as Efficient Catalyst for the Syntheses of Arylboronate Esters
1
698C; 76% yield. H NMR (400 MHz, CDCl3): d=5 (s, 12
H), 7.61 ( d, 2H, J=7.9 Hz), 7.91 (d, 2H, J=7.9 Hz).
4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-benzoic
acid methyl ester (Table 3, entry 5) (3af):[12] White solid; mp
116.4, 121.1, 146.2, 163.9; HR-MS (ESI): m/z=236.1459,
calcd. for C12H18BNO3 ([M+H]+): 236.1458.
4,4,5,5-Tetramethyl-2-(4-methylphenyl)-1,3,2-dioxaboro-
lane (Table 4, entry 4) (3ba):[16] Yellow oil; 85% yield.
1H NMR (400 MHz, CDCl3): d=1.33 (s, 12H), 2.36 (s, 3H),
7.18 (d, 2H, J=7.7 Hz), 7.70 (d, 2H, J=7.7 Hz).
1
78–798C; 85% yield. H NMR (400 MHz, CDCl3): d=1.35
(s, 12H), 3.92 (s, 3H), 7.87 (d, 2H, J=8.1 Hz), 8.02 (d, 2H,
J=8.1 Hz).
2-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-benzena-
mine (Table 4, entry 7) (3bb):[13] White solid; mp 67–688C;
1-[4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-phenyl]-
1
ethanone (Table 3, entry 6) (3ag):[12] White solid; mp 59–
58% yield. H NMR (400 MHz, CDCl3): d=1.32 (s, 12H),
1
4.72 (br s, 2H), 6.59 (d, 1H, J=8.1 Hz), 6.66 (m, 1H), 7.20
(m, 1H), 7.59 (dd, 1H, J=1.4 Hz, 7.3 Hz).
608C; >99% yield. H NMR (400 MHz, CDCl3): d=1.36 (s,
12H), 2.61 (s, 3H), 7.89 (d, 2H, J=8.2 Hz), 7.93 ( d, 2H, J=
8.2 Hz).
2-(3-Methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaboro-
lane (Table 3, entry 7) (3ah):[11] Colorless oil; 90% yield.
1H NMR (400 MHz, CDCl3): d=1.33 (s, 12H), 3.81 (s, 3H),
7.00 (dd, 1H, J=2.7 Hz, 8.2 Hz) 7.28 (t, 1H, J=7.8 Hz),
7.32 (s, 1H), 7.40 (d, 1H, J=6.8 Hz).
3-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-benzena-
mine (Table 4, entry 8) (3bc):[16] White solid; mp 88–898C;
1
91% yield. H NMR (400 MHz, CDCl3): d=1.32 (s, 12H),
3.65 (br s, 2H), 6.78 (dd, 1H, J=1.3 Hz, 9.8 Hz), 7.12–7.21
(m, 3H).
4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-2-pyridine-
carbonitrile (Table 4, entry 10) (3bd): White solid; mp 60–
1-[3-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-phenyl]-
1
ethanone (Table 3, entry 8) (3ai):[4b] White solid, mp 47–
618C; 75% yield. H NMR (400 MHz, CDCl3): d=1.36 (s,
1
12H), 7.84 (dt, 1H, J=3.8 Hz), 8.03 (s, 1H), 8.74 (t, 1H, J=
4.1 Hz); 13C NMR (100 MHz, CDCl3): d=24.7, 85.2, 117.2,
131.8, 133.3, 133.5, 150.4; HR-MS (ESI): m/z=231.1305,
calcd. for C12H16BN2O2 ([M+H]+): 231.1305.
488C; 94% yield. H NMR (400 MHz, CDCl3): d=1.36 (s,
12H), 2.64 (s, 3H), 7.47 (t, 1H, J=7.6 Hz), 7.99 (d, 1H, J=
7.6 Hz), 8.06 (m, 1H), 8.36 (s, 1H).
4,4,5,5-Tetramethyl-2-(2-nitrophenyl)-1,3,2-dioxaborolane
(Table 3, entry 9) (3aj):[14] Yellow oil; 72% yield. H NMR
1
(400 MHz, CDCl3): d=1.45 (s, 12H), 7.56 (m, 2H), 7.66 (m,
1H), 8.18 (d, 1H, J=7.9 Hz).
Acknowledgements
2-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-benzoni-
trile (Table 3, entry 10) (3ak):[13] Yellow solid; mp 79–808C;
We are grateful to the NSF of China (20772114, 20972139),
the NSF of Henan (082300423201) and Tetranov Biopharm,
Inc. for the financial support of this research. We thank Dr.
Weiguo Zhu and Mr. Jianxun Kang for their excellent analyt-
ical support.
1
78% yield. H NMR (400 MHz, CDCl3): d=1.40 (s, 12H),
7.57 (m, 2H), 7.71 (d, 1H, J=7.6 Hz), 7.91 (d, 1H, J=
7.6 Hz).
4,4,5,5-Tetramethyl-2-(1-naphthalenyl)-1,3,2-dioxaboro-
lane (Table 3, entry 11) (3al):[11] Yellow solid; mp 54–558C;
1
66% yield. H NMR (400 MHz, CDCl3): d=1.43 (s, 12H),
7.46–7.54 (m, 3H), 7.84 (d, 1H, J=7.7 Hz), 7.94 (d, 1H, J=
8.1 Hz), 8.08 (d, 1H, J=6.8 Hz), 8.77 (d, 1H, J=8.3 Hz).
4,4,5,5-Tetramethyl-2-(phenylmethyl)-1,3,2-dioxaborolane
References
[1] For reviews on the applications of arylboronic acids
and esters, see: a) N. Miyaura, A. Suzuki, Chem. Rev.
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2002, 219, 11–59; c) A. F. Littke, G. C. Fu, Angew.
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Preparation and Applications in Organic Synthesis and
Medicine, (Ed.: D. G. Hall), Wiley-VCH: Weinheim,
2005; 1–99.
1
(Table 3, entry 12) (3am):[15] Yellow oil; 85% yield. H NMR
(400 MHz, CDCl3): d=1.25 (s, 12H), 2.31 (s, 2H), 7.13 (m,
1H), 7.19–7.28 (m, 4H).
4,4,5,5-Tetramethyl-2-(3-thienyl)-1,3,2-dioxaborolane
(Table 3, entry 13) (3an):[4e] Yellow solid; mp 79–808C; 54%
yield. 1H NMR (400 MHz, CDCl3): d=1.33 (s, 12H), 7.34
(dt, 1H, J=2.6, 4.8), 7.41 (dt, 1H, J=0.7 Hz, 4.8 Hz), 7.92
(dt, 1H, J=1.7 Hz, 2.5 Hz).
4,4,5,5-Tetramethyl-2-(2-thienyl)-1,3,2-dioxaborolane
[2] J. Yan, H. Fang, B. H. Wang, Med. Res. Rev. 2005, 25,
490–520.
1
(Table 3, entry 14) (3ao):[11] Yellow oil; 46% yield. H NMR
(400 MHz, CDCl3): d=1.35 (s, 12H), 7.19 (dd, 1H, J=
3.5 Hz, 4.2 Hz), 7.64 (m, 2H).
[3] For reviews on transition metal-catalyzed carbon-boron
bond formation, see: a) T. Ishiyama, N. Miyaura, J. Or-
ganomet. Chem. 2000, 611, 392–402; b) T. Ishiyama, N.
Miyaura, J. Organomet. Chem. 2003, 680, 3–11; c) T.
Ishiyama, N. Miyaura, Chem. Rec. 2004, 3, 271–280.
[4] a) T. Ishiyama, M. Murata, N. Miyaura, J. Org. Chem.
1995, 60, 7508–7510; b) M. Murata, S. Watanabe, Y.
Masuda, J. Org. Chem. 2000, 65, 164–168; c) T. Ishiya-
ma, K. Ishida, N. Miyaura, Tetrahedron 2001, 57, 9813–
9816; d) M. Murata, T. Sambommatsu, S. Watanabe, Y.
Masuda, Synlett 2006, 12, 1867–1870; e) K. L. Billings-
ley, T. E. Barder, S. L. Buchwald, Angew. Chem. 2007,
119, 5455–5459; Angew. Chem. Int. Ed. 2007, 46, 5359–
5363; f) K. L. Billingsley, S. L. Buchwald, J. Org. Chem.
2008, 73, 5589–5591; g) H. A. Duong, S. Chua, P. B.
N,N-Dimethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)-2-pyridinamine (Table 3, entry 15) (3ap): White solid;
1
mp 89–908C; 74% yield. H NMR (400 MHz, CDCl3): d=
1.31 (s, 12H), 3.11 (s, 6H), 6.46 (d, 1H, J=8.5 Hz), 7.78 (dd,
J=1.9 Hz, 8.6 Hz), 8.53 (d, 1H, J=1.4 Hz); 13C NMR
(100 MHz, CDCl3): d=24.7, 37.8, 83.2, 104.7, 143.0, 155.1,
160.5; HR-MS (ESI): m/z=249.1773, calcd.
for
C13H21BN2O2 ([M+H]+): 249.1774.
2-Methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-
pyridine (Table 3, entry 16) (3aq): Yellow oil; 91% yield.
1H NMR (400 MHz, CDCl3): d=1.34 (s, 1H), 3.92 (s, 3H),
7.12 (s, 1H), 7.18 (d, 1H, J=4.9 Hz), 8.18 (d, 1H, J=
4.9 Hz); 13C NMR (100 MHz, CDCl3): d=24.7, 53.2, 84.3,
Adv. Synth. Catal. 2010, 352, 2002 – 2010
ꢁ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2009