Abstract
The β-elimination of an organophosphoryl group from an
iminyl radical is observed for the first time. On the basis of this finding,
radical cyanation of alkyl iodides is achieved by using diethylphosphoryl
cyanide.
Key words
radical - cyanide - elimination - alkyl
halides
References and Notes
<A NAME="RU09508ST-1A">1a </A>
Clive DLJ.
Kang S.
Tetrahedron
Lett.
2000,
41:
1315
<A NAME="RU09508ST-1B">1b </A>
Clive DLJ.
Kang S.
J.
Org. Chem.
2001,
66:
6083
<A NAME="RU09508ST-2">2 </A>
Ouvry G.
Quiclet-Sire B.
Zard SZ.
Angew.
Chem. Int. Ed.
2006,
45:
5002
<A NAME="RU09508ST-3A">3a </A>
Leca D.
Fensterbank L.
Lacote E.
Malacria M.
Angew.
Chem. Int. Ed.
2004,
43:
4220
<A NAME="RU09508ST-3B">3b </A>
Leca D.
Fensterbank L.
Lacote E.
Malacria M.
Chem. Soc. Rev.
2005,
34:
858
<A NAME="RU09508ST-4A">4a </A>
Kim S.
Cho CH.
Lim CJ.
J. Am. Chem. Soc.
2003,
125:
9574
<A NAME="RU09508ST-4B">4b </A>
Cho CH.
Kim S.
Yamane M.
Miyauchi H.
Narasaka K.
Bull. Chem.
Soc. Jpn.
2005,
78:
1665
<A NAME="RU09508ST-4C">4c </A>
Cho CH.
Kim S.
Can. J. Chem.
2005,
83:
917
<A NAME="RU09508ST-5A">5a </A>
Scott AI.
Kang K.
J.
Am. Chem. Soc.
1977,
99:
1997
<A NAME="RU09508ST-5B">5b </A>
Wollowitz S.
Halpern J.
J. Am. Chem. Soc.
1988,
110:
3112
<A NAME="RU09508ST-5C">5c </A>
Dowd P.
Wilk B.
Wilk BK.
J.
Am. Chem. Soc.
1992,
114:
7949
<A NAME="RU09508ST-5D">5d </A>
Kim S.
Jon SY.
Chem. Commun.
1996,
1335
<A NAME="RU09508ST-6A">6a </A>
Curran DP.
Diederichsen U.
Palovich M.
J. Am. Chem. Soc.
1997,
119:
4797
<A NAME="RU09508ST-6B">6b </A>
Curran DP.
Palovich M.
Synlett
1992,
631
<A NAME="RU09508ST-6C">6c </A>
Curran DP.
Liu H.
J. Org. Chem.
1991,
56:
3463
<A NAME="RU09508ST-6D">6d </A>
Kiyooka S.
Kaneko Y.
Matsue H.
Hamada M.
Fujiyama R.
J.
Org. Chem.
1990,
55:
5562
<A NAME="RU09508ST-7">7 </A>
Kim S.
Cheong JH.
Chem. Commun.
1998,
1143
<A NAME="RU09508ST-8A">8a </A>
Scott FL.
Riordan R.
Morton PD.
J. Org. Chem.
1962,
27:
4255
<A NAME="RU09508ST-8B">8b </A>
Shioiri T.
Ninomiya K.
Yamada S.
J.
Am. Chem. Soc.
1972,
94:
6203
<A NAME="RU09508ST-8C">8c </A>
Yamada S.
Ninomiya K.
Shioiri T.
Tetrahedron
Lett.
1973,
14:
2343
<A NAME="RU09508ST-9A">9a </A>
Ollivier C.
Renaud P.
J.
Am. Chem. Soc.
2000,
122:
6496
<A NAME="RU09508ST-9B">9b </A>
Ollivier C.
Renaud P.
J. Am. Chem. Soc.
2001,
123:
4717
<A NAME="RU09508ST-9C">9c </A>
Masterson DS.
Porter NA.
Org.
Lett.
2002,
4:
4253
<A NAME="RU09508ST-9D">9d </A>
Panchaud P.
Chabaud L.
Landais Y.
Ollivier C.
Renaud P.
Zigmantas S.
Chem. Eur. J.
2004,
10:
3606
<A NAME="RU09508ST-10A">10a </A>
Renaud P.
Ollivier C.
Panchaud P.
Angew. Chem. Int. Ed.
2002,
69:
3460
<A NAME="RU09508ST-10B">10b </A>
Panchaud P.
Ollivier C.
Renaud P.
Zigmantas S.
J. Org. Chem.
2004,
69:
2755
<A NAME="RU09508ST-11A">11a </A>
Fang J.-M.
Chen M.-Y.
Tetrahedron
Lett.
1987,
28:
2853
<A NAME="RU09508ST-11B">11b </A>
Barton DHR.
Jaszberenyi JC.
Theodorakis EA.
Tetrahedron
1992,
48:
2613
<A NAME="RU09508ST-11C">11c </A>
Kim S.
Song HJ.
Synlett
2002,
2110
<A NAME="RU09508ST-11D">11d </A>
Kim S.
Lim CJ.
Angew. Chem. Int. Ed.
2002,
41:
3265
<A NAME="RU09508ST-11E">11e </A>
Schaffner A.
Darnency V.
Renaud P.
Angew.
Chem. Int. Ed.
2006,
45:
5847
<A NAME="RU09508ST-12">12 </A>
Saunders BC.
Stacey GT.
Wild F.
Wiling IGE.
J.
Chem. Soc.
1948,
699
<A NAME="RU09508ST-13A">13a </A>
Shi E.
Pei C.
Synth.
Commun.
2005,
35:
669
<A NAME="RU09508ST-13B">13b </A>
Shi E.
Pei C.
Synthesis
2004,
2995
<A NAME="RU09508ST-13C">13c </A>
Shi E.
Pei C.
Synth. Commun.
2004,
34:
1285
<A NAME="RU09508ST-13D">13d </A>
Shi E.
Pei C.
Phosphorus, Sulfur Silicon Relat.
Elem.
2003,
178:
1093
<A NAME="RU09508ST-14">14 </A>
Coskran KJ.
Jones CE.
Inorg. Chem.
1971,
10:
1536
For reviews, see:
<A NAME="RU09508ST-15A">15a </A>
Baguley PA.
Walton JC.
Angew. Chem.
Int. Ed.
1998,
37:
3072
<A NAME="RU09508ST-15B">15b </A>
Studer A.
Amrein S.
Synthesis
2002,
835
<A NAME="RU09508ST-15C">15c </A>
Quiclet-Sire B.
Zard SZ.
Chem. Eur. J.
2006,
12:
6002
<A NAME="RU09508ST-16A">16a </A>
Barton DHR.
Jang DO.
Jaszberenyi JC.
Tetrahedron
Lett.
1992,
33:
5709
<A NAME="RU09508ST-16B">16b </A>
Barton DHR.
Jang DO.
Jaszberenyi JC.
J. Org. Chem.
1993,
58:
6838
<A NAME="RU09508ST-16C">16c </A>
Graham SR.
Murphy JA.
Coates D.
Tetrahedron Lett.
1999,
40:
2415
<A NAME="RU09508ST-16D">16d </A>
Martin CG.
Murphy JA.
Smith CR.
Tetrahedron Lett.
2000,
41:
1833
<A NAME="RU09508ST-16E">16e </A>
Jang DO.
Cho DH.
Chung C.-M.
Synlett
2001,
1923
<A NAME="RU09508ST-17">17 </A>
Typical Procedure
for Radical Cyanation
Photochemical
Conditions A
A dry benzene solution (2 mL) of 4-phenoxybutyl
iodide (2 , 55 mg, 0.2 mmol), diethylphosphoryl
cyanide (3 , 90 µL, 0.6 mmol),
and hexamethylditin (79 mg, 0.24 mmol) in a quartz tube was degassed
with nitrogen for 10 min and then irradiated at 300 nm in Rayonet
photochemical reactor for 12 h. The solvent was evaporated under
reduced pressure, and the residue was separated by a silica gel
column chromatography using EtOAc and n -hexane
(1:5) as eluant to give 4-phenoxybutyl cyanide (28 mg, 80%).¹¹d MW (C11 H13 NO):
175.23. ¹ H NMR (400 MHz, CDCl3 ): δ = 1.85-1.95
(m, 4 H), 2.41-2.45 (t, J = 6.7
Hz, 2 H), 3.98-4.00 (t, J = 5.7
Hz, 2 H), 6.85-6.92 (d, J = 5.6
Hz, 2 H), 6.93-6.95 (t, J = 7.3
Hz, 1 H), 7.23-7.28 (m, 2 H). ¹³ C
NMR (100 MHz, CDCl3 ): δ = 16.6,
22.0, 27.8, 66.0, 113.9, 119.0, 120.4, 129.0, 158.2. IR (polymer):
2927, 1601, 1586, 1497, 1474, 1247, 757, 693 cm-¹ .
HRMS: m/z calcd for C11 H13 NO [M+ ]:
175.0997; found: 175.0998.
Thermal
Conditions B
A solution of 2 (110
mg, 0.4 mmol), 3 (180 µL, 1.2
mmol), and DLP (31 mg, 0.08 mmol) in chlorobenzene (4 mL) was degassed
with nitrogen for 10 min, and then the solution was heated at 110 ˚C
under nitrogen for 24 h. The solvent was evaporated under reduced
pressure, and the residue was separated by a silica gel column chromatography
using EtOAc and n -hexane (1:5) as eluant
to give 4-phenoxybutyl cyanide (35 mg, 50%) with recovery
of 2 (22 mg, 20%).