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DOI: 10.1055/s-0034-1378382
Applications of Allenylsilanes in Organic Synthesis
Publication History
Publication Date:
28 July 2014 (online)
Introduction
Allenylsilanes 2 are versatile reagents widely used in organic synthesis.[1] Generally, allenylsilanes react as propargyl anion equivalents in Lewis acid mediated[2] or thermal[3] nucleophilic addition to electrophiles such as carbonyls, imines, Selectfluor, and N-bromosuccinimide, etc.[1] [4] [5] The regiospecific addition of allenylsilanes provides a β-vinyl cation, which is stabilized by a C–Si bond, which is called β effect. The C–Si bond in allenylsilanes is oriented cis-coplanar to the p-orbital of the carbocation and provides direct stabilization.[5] Allenylsilanes undergo [3+2] annulations with α,β-unsaturated carbonyls, carbonyl compounds, imines, and nitrosyl cations to form cyclo-pentenones, dihydrofurans, dihydropyrroles, and isoxazoles, respectively.[1] [4] [5]
The efficient methods for the synthesis of allenylsilanes 2 are copper-mediated 1,3-substitution reactions of carbon nucleophiles to propargylic substrates 1 having a leaving group at the propargylic position.[6] [7]
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References
- 1a Marshall JA. J. Org. Chem. 2007; 72: 8153
- 1b Bower JF, Kim IS, Patman RL, Krische MJ. Angew. Chem. Int. Ed. 2009; 48: 34
-
1c Yu S, Ma S. Angew. Chem. Int. Ed. 2012; 51: 3074
- 2a Felzmann W, Castagnolo D, Rosenbeiger D, Mulzer J. J. Org. Chem. 2007; 72: 2182
- 2b Brawn RA, Panek JS. Org. Lett. 2009; 11: 4362
- 3 Sabbasani VR, Lee D. Org. Lett. 2013; 15: 3954
- 4 Fuchs PL. Handbook of Reagents for Organic Synthesis: Reagents for Silicon-Mediated Organic Synthesis. John Wiley & Sons; Chichester: 2011
- 5 Curtis-Long MJ, Aye Y. Chem. Eur. J. 2009; 15: 5402
- 6 Li H, Müller D, Guénée L, Alexakis A. Org. Lett. 2012; 14: 5880
- 7a Brummond KM, DeForrest JE. Synthesis 2007; 795
- 7b Ding C.-H, Hou X.-L. Chem. Rev. 2011; 111: 1914
-
7c Yu S, Ma S. Chem. Commun. 2011; 47: 5384
- 8 Adachi Y, Kamei N, Yokoshima S, Fukuyama T. Org. Lett. 2011; 13: 4446
- 9 Guinchard X, Roulland E. Org. Lett. 2009; 11: 4700
- 10 Maity P, Lepore SD. J. Am. Chem. Soc. 2009; 131: 4196
- 11 Brawn RA, Panek JS. Org. Lett. 2009; 11: 473
- 12 Dudnik AS, Xia Y, Li Y, Gevorgyan V. J. Am. Chem. Soc. 2010; 132: 7645
- 13 Williams DR, Shah AA, Mazumder S, Baik M.-H. Chem. Sci. 2013; 4: 238
- 14 Hwu JR, Swain SP. Chem. Eur. J. 2013; 19: 6556