Detrifluoroacetylative Generation of Halogenated Enolates: Practical Access to Perhalogenated Ketones and Alkenes

Kaluvu Balaraman; Max Moskowitz; Yang Liu; Christian Wolf

doi:10.1055/s-0035-1561433

Synthesis, Table of Contents

Synthesis 2016; 48(15): 2376-2384
DOI: 10.1055/s-0035-1561433

feature

Detrifluoroacetylative Generation of Halogenated Enolates: Practical Access to Perhalogenated Ketones and Alkenes

Kaluvu Balaraman

Georgetown University, Chemistry Department, Washington, DC, USA Email: cw27@georgetown.edu

,

Max Moskowitz

Georgetown University, Chemistry Department, Washington, DC, USA Email: cw27@georgetown.edu

,

Yang Liu

Georgetown University, Chemistry Department, Washington, DC, USA Email: cw27@georgetown.edu

,

Christian Wolf*

Georgetown University, Chemistry Department, Washington, DC, USA Email: cw27@georgetown.edu

› Author Affiliations

Abstract

All articles of this category

Abstract

Sequential chlorination/fluorination of aromatic trifluoroacetylated ketones gives 1-aryl 2-chloro-2,4,4,4-tetrafluorobutan-1,3-dione hydrates that are used for the synthesis of ketones and alkenes exhibiting a terminal bromochlorofluoromethyl group. The hydrates undergo detrifluoroacetylative cleavage and subsequent bromination in the presence of a copper(II) bisoxazoline catalyst, K₂CO₃, and NBS at room temperature. The corresponding bromochlorofluoromethyl ketones can be applied in Wittig and Horner–Wadsworth–Emmons reactions and dibromoalkenylations.

Key words

fluorine - halogenation - olefination - Wittig reaction - halogens

Full Text

References

References

1a Smith BR, Eastman CM, Njardarson JT. J. Med. Chem. 2014; 57: 9764
1b Wang J, Sanchez-Rosello M, Acena JL, del Pozo C, Sorochinsky AE, Fustero S, Soloshonok VA, Liu H. Chem. Rev. 2014; 114: 2432

2 Zhou Y, Wang J, Gu Z, Wang S, Zhu W, Acena JL, Soloshonok VA, Izawa K, Liu H. Chem. Rev. 2016; 116: 422

3a Hargreaves MK, Barrett GC, Hall DM, Modarai B. J. Chem. Soc. C 1971; 279
3b Hargreaves MK, Modarai B. J. Chem. Soc. C 1971; 1013
3c Doyle TR, Vogl O. J. Am. Chem. Soc. 1989; 111: 8510
3d Doyle TR, Vogl O. Monatsh. Chem. 1990; 121: 31

4a Yang Z.-Y. J. Org. Chem. 2003; 68: 4410
4b Zhao Y, Gao B, Hu J. J. Am. Chem. Soc. 2012; 134: 5790

5a Kvicala J, Stambasky J, Skalicky M, Paleta O. J. Fluorine Chem. 2005; 126: 1390
5b Petko KI, Kot SY, Yagupolskii LM. J. Fluorine Chem. 2008; 129: 1119
5c Matsnev AV, Qing S.-Y, Stanton MA, Berger KA, Haufe G, Thrasher JS. Org. Lett. 2014; 16: 2402
5d Shiosaki M, Inoue M. J. Fluorine Chem. 2015; 175: 160

6 Mei H, Nie C, Acena JL, Soloshonok VA, Roeschenthaler G.-V, Han J. Eur. J. Org. Chem. 2015; 6401
7 Prager JH, Ogden PH. J. Org. Chem. 1968; 33: 2100
8 Han C, Kim EH, Colby DA. J. Am. Chem. Soc. 2011; 133: 5802
9 Prakash GK. S, Zhang Z, Wang F, Munoz S, Olah GA. J. Org. Chem. 2013; 78: 3300

10a Han C, Kim EH, Colby DA. Synlett 2012; 1559
10b Riofski MV, Hart AD, Colby DA. Org. Lett. 2013; 15: 208

11 Li W, Zhu X, Mao H, Tang Z, Cheng Y, Zhu C. Chem. Commun. 2014; 50: 7521

12a Xie C, Wu L, Mei H, Soloshonok VA, Han J, Pan Y. Tetrahedron Lett. 2014; 55: 5908
12b Xie C, Wu L, Zhou J, Mei H, Soloshonok VA, Han J, Pan Y. J. Fluorine Chem. 2015; 172: 13
12c Xie C, Wu L, Mei H, Soloshonok VA, Han J, Pan Y. Org. Biomol. Chem. 2014; 12: 7836
12d Xie C, Wu L, Han J, Soloshonok VA, Pan Y. Angew. Chem. Int. Ed. 2015; 54: 6019
12e Xie C, Dai Y, Mei H, Han J, Soloshonok VA, Pan Y. Chem. Commun. 2015; 51: 9149

13 Wu C, Li G, Sun W, Zhang M, Hong L, Wang R. Org. Lett. 2014; 16: 1960

14a Saidalimu I, Fang X, He XP, Liang J, Yang XY, Wu FH. Angew. Chem. Int. Ed. 2013; 52: 5566
14b Saidalimu I, Fang X, Lv W, Yang X, He X, Zhang J, Wu FH. Adv. Synth. Catal. 2013; 355: 857

15a Zhang P, Wolf W. J. Org. Chem. 2012; 77: 8840
15b Zhang P, Wolf W. Angew. Chem. Int. Ed. 2013; 52: 7869

16 John JP, Colby DA. J. Org. Chem. 2011; 76: 9163
17 Pravst I, Zupan M, Stavber S. Tetrahedron 2008; 64: 5191
18 The reaction was carried out with 5 equiv of LiBr, 2.5 equiv of K₂CO₃, and 2 equiv of NBS using THF as solvent at r.t. Complete conversion of 5 was observed within 1 h.
19 The trapping of chlorofluoro-substituted enolates such as 7 with NIS or I₂ is also possible, but the corresponding chlorofluoroiodomethyl ketones are considerably less stable than 8 and its analogues.
20 Ramirez F, Desai NB, McKelvie N. J. Am. Chem. Soc. 1962; 84: 1745
21 The Z-isomer was not detected.

22a Burton DJ, Koppes WM. J. Org. Chem. 1975; 40: 3026
22b Eguchi T, Aoyama T, Kakinuma K. Tetrahedron Lett. 1992; 33: 5545

Supplementary Material

Supporting Information