E
K. Dong et al.
Letter
Synlett
References and Notes
(8) (a) Ireland, R. E.; Mueller, R. H.; Willard, A. K. J. Am. Chem. Soc.
1976, 98, 2868. (b) Fataftah, Z. A.; Kopka, I. E.; Rathke, M. W.
J. Am. Chem. Soc. 1980, 102, 3959. (c) Corey, E. J.; Gross, A. W.
Tetrahedron Lett. 1984, 25, 495.
(1) For reviews, see: (a) Xu, X.; Doyle, M. P. Acc. Chem. Res. 2014, 47,
1396. (b) Deng, Y.; Cheng, Q.-Q.; Doyle, M. P. Synlett 2017, 28,
1695. (c) Cheng, Q.-Q.; Deng, Y.; Lankelma, M.; Doyle, M. P.
Chem. Soc. Rev. 2017, 46, 5425. (d) Yin, Z.; He, Y.; Chiu, P. Chem.
Soc. Rev. 2018, 47, 8881. (e) Marichev, K. O.; Doyle, M. P. Org.
Biomol. Chem. 2019, 17, 4183.
(2) For recent research articles, see: (a) Li, S.-J.; Fang, D.-C. Organo-
metallics 2018, 37, 1373. (b) Marichev, K. O.; Adly, F. G.;
Carranco, A. M.; Garcia, E. C.; Arman, H.; Doyle, M. P. ACS Catal.
2018, 8, 10392.
(3) (a) Deng, Y.; Massey, L. A.; Zavalij, P.; Doyle, M. P. Angew. Chem.
Int. Ed. 2017, 56, 7479. (b) Deng, Y.; Massey, L. A.; Rodriguez
Núñez, Y. A.; Arman, H.; Doyle, M. P. Angew. Chem. Int. Ed. 2017,
56, 12292. (c) Xu, X.; Zavalij, P. Y.; Hu, W.; Doyle, M. P. J. Org.
Chem. 2013, 78, 1583. (d) Xu, X.; Zavalij, P. J.; Doyle, M. P. Chem.
Commun. 2013, 49, 10287. (e) Qian, Y.; Xu, X.; Wang, X.; Zavalij,
P. J.; Hu, W.; Doyle, M. P. Angew. Chem. Int. Ed. 2012, 51, 5900.
(f) Xu, X.; Zavalij, P. J.; Doyle, M. P. Angew. Chem. Int. Ed. 2012,
51, 9829.
(4) (a) Shved, A. S.; Tabolin, A. A.; Novikov, R. A.; Nelyubina, Y. V.;
Timofeev, V. P.; Ioffe, S. L. Eur. J. Org. Chem. 2016, 5569. (b) Zhu,
C.; Xu, G. Sun J. 2016, 55, 11867. (c) Nocquet, P.-A.; Opatz, T. Eur.
J. Org. Chem. 2016, 1156. (d) Xu, X.; Wang, X.; Zavalij, P. Y.;
Doyle, M. P. Org. Lett. 2015, 17, 790.
(9) General Procedure for the Preparation of (Z)-Enoldiazoace-
tates 3: A 10 mL oven-dried vial equipped with a magnetic stir-
ring bar was charged with diazoacetate 2 (0.50 mmol) and the
system was filled with nitrogen. THF (2.0 mL) was then added,
and the reaction solution was cooled to –78 °C (dry ice/acetone
bath). LiHMDS (0.60 mL, 1.0 M in the hexanes) was introduced
dropwise in 2 min, followed by the addition of TIPSOTf (168.5
mg, 0.55 mmol) at –78 °C. The resulting solution was stirred at
–78 °C until the reaction was complete (monitored by TLC,
about 5–15 min). THF was then removed under reduced pres-
sure, and the residue was purified by column chromatography
on silica gel which was pretreated with triethylamine
(5 vol.%)/hexanes (eluent: pure hexanes) to give the desired
products 3 in high yields and excellent stereoselectivity.
Methyl
(Z)-2-Diazo-3-[(triisopropylsilyl)oxy]hex-3-enoate
(3a): Orange oil; Yield: 138 mg (88%). 1H NMR (500 MHz,
CDCl3): = 5.07 (t, J = 7.2 Hz, 1 H), 3.80 (s, 3 H), 2.15–2.22
(comp, 2 H), 1.24–1.16 (comp, 3 H), 1.12 (d, J = 6.6 Hz, 18 H),
1.01 (t, J = 7.4 Hz, 3 H), 13C NMR (125 MHz, CDCl3): = 165.8,
133.4, 116.3, 52.1, 19.7, 18.0, 14.1, 13.5; HRMS (ESI): m/z [M + H]+
calcd for C16H31N2O3Si: 327.2098; found: 327.2093.
Methyl (Z)-2-Diazo-3-[(triisopropylsilyl)oxy]pent-3-enoate
(3b): Orange oil; Yield: 111 mg (71%). 1H NMR (500 MHz,
CDCl3): = 5.13 (q, J = 7.0 Hz, 1 H), 3.77 (s, 3 H), 1.70 (d, J = 7.0
Hz, 3 H), 1.20–1.13 (comp, 3 H), 1.10 (d, J = 6.7 Hz, 18 H); 13C
NMR (125 MHz, CDCl3): = 165.8, 134.7, 108.7, 52.1, 18.0, 13.5,
(5) (a) Wang, X.; Zhou, Y.; Qiu, L.; Yao, R.; Zheng, Y.; Zhang, C.; Bao,
X.; Xu, X. Adv. Synth. Catal. 2016, 358, 1571. (b) Deng, Y.; Jing, C.;
Doyle, M. P. Chem. Commun. 2015, 51, 12924.
(6) (a) Fleming, I. Organic silicon chemistry., In: Comprehensive
organic chemistry, Vol. 3; Barton, D. H. R.; Ollis, W. D., Ed.; Per-
gamon: Oxford, 1979, 541. (b) Brownbridge, P. Synthesis 1983,
1. (c) Weber, W. P. Preparation of Silyl Enol Ethers, In: Silicon
Reagents for Organic Synthesis. Reactivity and Structure Concepts
in Organic Chemistry, Vol. 14; Springer: Berlin/Heidelberg, 1983.
(d) Fleming, I. A primer in organmilicon biochemistry, In: Silicon
Biochemistry (Ciba Foundation Symposium No. 121); Wiley: New
York, 1986, 112. (e) Walshe, N. D. A.; Goodwin, G. B. T.; Smith, G.
C.; Woodward, F. E. Org. Synth. 1987, 65, 1.
11.9; HRMS (ESI): m/z [M
+
H]+ calcd for C15H29N2O3Si:
313.1942; found: 313.1935.
Methyl (Z)-2-Diazo-5-phenyl-3-[(triisopropylsilyl)oxy]pent-
3-enoate (3c): Orange oil, Yield 165 mg (85%). 1H NMR (500
MHz, CDCl3): = 7.29 (t, J = 7.5 Hz, 2 H), 7.23 (d, J = 7.1 Hz, 2 H),
7.19 (t, J = 7.2 Hz, 1 H), 5.31 (t, J = 7.4 Hz, 1 H), 3.78 (s, 3 H), 3.54
(d, J = 7.4 Hz, 2 H), 1.26–1.18 (comp, 3 H), 1.13 (d, J = 6.9 Hz, 18
H); 13C NMR (125 MHz, CDCl3) = 165.6, 141.0, 134.6, 128.5,
128.5, 126.1, 112.6, 52.1, 32.5, 18.0, 13.5; HRMS (ESI): m/z [M + H]+
calcd for C21H33N2O3Si: 389.2255; found: 389.2251.
(7) Lienhard, G. E.; Wang, T.-C. J. Am. Chem. Soc. 1969, 91, 1146.
For more examples, see the Supporting Information.
(10) Jing, C.; Cheng, Q.-Q.; Deng, Y.; Arman, H.; Doyle, M. P. Org. Lett.
2016, 18, 4550.
© 2019. Thieme. All rights reserved. — Synlett 2019, 30, A–E