Abstract
We have studied the carbon radical addition to imine derivatives as an effective carbon-carbon
bond forming method for the synthesis of a variety of amines. The reaction of oxime
ethers proceeded smoothly in the presence of BF3·OEt2 to give the alkylated products in high yields via the free radical-mediated carbon-carbon
bond forming process. Intermolecular radical addition to oxime ethers was effectively
improved by using alkyl iodides and triethylborane, which acts multiply as a Lewis
acid, a radical initiator and a terminator. The asymmetric synthesis of α-amino acids
based on a diastereoselective radical addition to glyoxylic imine derivatives was
achieved. Highly diastereoselective alkyl radical addition to Oppolzer’s camphorsultam
derivatives of oxime ether provided a convenient method for preparing the enantiomerically
pure α,β-dialkyl-β-amino acids. We have demonstrated that imine derivatives such as
oxime ethers, hydrazones, and nitrones are excellent radical acceptors for the radical
reactions in aqueous medium. The radical addition to imine derivatives in aqueous
medium was also studied by using indium or zinc as a single-electron transfer radical
initiator. We have found that triethylborane can be applied to solid-phase radical
reactions. The solid-phase tandem carbon-carbon bond forming reaction of oxime ethers
connected with an α,β-unsaturated carbonyl group proceeded effectively to give the
azacycles or chiral oxacycles after cleavage from the resin.
-
1 Introduction
-
2 Intermolecular Radical Addition to Imine Derivatives
-
2.1 Addition to Oxime Ethers
-
2.2 Reactivity of Imine Derivatives
-
2.3 Iodine Atom-Transfer Reaction
-
3 Stereocontrol in Radical Addition to Imine Derivatives
-
3.1 Addition to Chiral Glyoxylic Oxime Ether
-
3.2 Addition to Chiral Unactivated Oxime Ether
-
3.3 Addition to Chiral Nitrone
-
4 Radical Reaction of Imine Derivatives in Aqueous Media
-
4.1 One-Pot Reaction
-
4.2 Triethylborane-Mediated Reaction in Aqueous Media
-
4.3 Zinc-Mediated Reaction in Aqueous Media
-
5 Solid-Phase Radical Reaction
-
5.1 Intermolecular Radical Reaction
-
5.2 Intramolecular Radical Reaction
-
5.3 Tandem Radical Addition-Cyclization
-
5.4 Solid-Phase Radical Reaction in Aqueous Media
-
6 Conclusion
Key words
radical - imine - oxime ether - amino acid - water - solid-phase - hydrazone - nitrone
References
<A NAME="RA34003ST-1A">1a</A>
Fossey J.
Lefort D.
Sorba J.
Free Radicals in Organic Chemistry
John Wiley & Sons;
New York:
1995.
<A NAME="RA34003ST-1B">1b</A>
Ryu I.
Sonoda N.
Curran DP.
Chem. Rev.
1996,
96:
177
<A NAME="RA34003ST-1C">1c</A>
Snider BB.
Chem. Rev.
1996,
96:
339
<A NAME="RA34003ST-1D">1d</A>
Giese B.
Kopping B.
Göbel T.
Dickhaut J.
Thoma G.
Kulicke KJ.
Trach F.
Org. React.
1996,
48:
301
<A NAME="RA34003ST-1E">1e</A>
Renaud P.
Gerster M.
Angew. Chem. Int. Ed.
1998,
37:
2562
<A NAME="RA34003ST-1F">1f</A>
Sibi MP.
Porter NA.
Acc. Chem. Res.
1999,
32:
163
<A NAME="RA34003ST-1G">1g</A>
Bowman WR.
Bridge CF.
Brookes P.
J. Chem. Soc., Perkin Trans. 1
2000,
1
<A NAME="RA34003ST-1H">1h</A>
Radicals in Organic Synthesis
Vol. 1 and 2:
Renaud P.
Sibi MP.
Wiley-VCH;
Weinheim:
2001.
For reviews see:
<A NAME="RA34003ST-2A">2a</A>
Hanamoto T.
Inanaga J.
Tetrahedron Lett.
1991,
32:
3555
<A NAME="RA34003ST-2B">2b</A>
Russell GA.
Yao C.-F.
Rajaratnam R.
Kim BH.
J. Am. Chem. Soc.
1991,
113:
373
<A NAME="RA34003ST-2C">2c</A>
Russell GA.
Wang L.
Rajaratnam R.
J. Org. Chem.
1996,
61:
8988
<A NAME="RA34003ST-2D">2d</A>
Bhat B.
Swayze EE.
Wheeler P.
Dimock S.
Perbost M.
Sanghvi YS.
J. Org. Chem.
1996,
61:
8186
<A NAME="RA34003ST-2E">2e</A>
Bloch R.
Chem. Rev.
1998,
98:
1407
<A NAME="RA34003ST-3A">3a</A>
Risch N.
Arend N.
Methods of Organic Chemistry, Houben-Weyl, Stereoselective Synthesis
E21, Vol. 3:
Helmchen G.
Hoffmann RW.
Mulzer J.
Schaumann E.
Thieme;
Stuttugart:
1996.
p.1833-2009
<A NAME="RA34003ST-3B">3b</A>
Volkmann RA.
Comprehensive Organic Synthesis
Vol. 1:
Trost BM.
Pergamon Press;
Oxford:
1991.
p.355-396
<A NAME="RA34003ST-3C">3c</A>
Enders D.
Reinhold U.
Tetrahedron: Asymmetry
1997,
8:
1895
<A NAME="RA34003ST-3D">3d</A>
Denmark SE.
Nicaise OJ.-C.
Chem. Commun.
1997,
999
For reviews and selected examples see:
<A NAME="RA34003ST-4A">4a</A>
Fallis AG.
Brinza IM.
Tetrahedron
1997,
53:
17543
<A NAME="RA34003ST-4B">4b</A>
Naito T.
Heterocycles
1999,
50:
505
<A NAME="RA34003ST-4C">4c</A>
Parker KA.
Fokas D.
J. Org. Chem.
1994,
59:
3927
<A NAME="RA34003ST-4D">4d</A>
Della EW.
Knill AM.
Aust. J. Chem.
1994,
47:
1833
<A NAME="RA34003ST-4E">4e</A>
Hollingworth GJ.
Pattenden G.
Schulz DJ.
Aust. J. Chem.
1995,
48:
381
<A NAME="RA34003ST-4F">4f</A>
Chiara JL.
Marco-Contelles J.
Khiar N.
Gallego P.
Destabel C.
Bernabé M.
J. Org. Chem.
1995,
60:
6010
<A NAME="RA34003ST-4G">4g</A>
Santagostino M.
Kilburn JD.
Tetrahedron Lett.
1995,
36:
1365
<A NAME="RA34003ST-4H">4h</A>
Keck GE.
Wager TT.
J. Org. Chem.
1996,
61:
8366
<A NAME="RA34003ST-4I">4i</A>
Marco-Contelles J.
Gallego P.
Rodríguez-Fernández M.
Khiar N.
Destabel C.
Bernabé M.
Martínez-Grau A.
Chiara JL.
J. Org. Chem.
1997,
62:
7397
<A NAME="RA34003ST-4J">4j</A>
Clive DLJ.
Zhang J.
Chem. Commun.
1997,
549
<A NAME="RA34003ST-4K">4k</A>
Iserloh U.
Curran DP.
J. Org. Chem.
1998,
63:
4711
<A NAME="RA34003ST-4L">4l</A>
Boiron A.
Zillig P.
Faber D.
Giese B.
J. Org. Chem.
1998,
63:
5877
For reviews see:
<A NAME="RA34003ST-5A">5a</A>
Friestad GK.
Tetrahedron
2001,
57:
5461
<A NAME="RA34003ST-5B">5b</A>
Miyabe H.
Naito T.
J. Synth. Org. Chem. Jpn.
2001,
59:
35
<A NAME="RA34003ST-5C">5c</A>
Miyabe H.
Yakugaku Zasshi
2003,
123:
285
<A NAME="RA34003ST-6">6</A>
Hart DJ.
Seely FL.
J. Am. Chem. Soc.
1988,
110:
1631
<A NAME="RA34003ST-7A">7a</A>
Kim S.
Lee IY.
Yoon J.-Y.
Oh DH.
J. Am. Chem. Soc.
1996,
118:
5138
<A NAME="RA34003ST-7B">7b</A>
Kim S.
Yoon J.-Y.
J. Am. Chem. Soc.
1997,
119:
5982
<A NAME="RA34003ST-7C">7c</A>
Kim S.
Yoon J.-Y.
Lee IY.
Synlett
1997,
475
<A NAME="RA34003ST-7D">7d</A>
Kim S.
Cheong JH.
Chem. Commun.
1998,
1143
<A NAME="RA34003ST-7E">7e</A>
Ryu I.
Kuriyama H.
Minakata S.
Komatsu M.
Yoon J.-Y.
Kim S.
J. Am. Chem. Soc.
1999,
121:
12190
<A NAME="RA34003ST-8A">8a</A>
Miyabe H.
Shibata R.
Ushiro C.
Naito T.
Tetrahedron Lett.
1998,
39:
631
<A NAME="RA34003ST-8B">8b</A>
Miyabe H.
Shibata R.
Sangawa M.
Ushiro C.
Naito T.
Tetrahedron
1998,
54:
11431
<A NAME="RA34003ST-9">9</A>
Miyabe H.
Ushiro C.
Naito T.
Chem. Commun.
1997,
1789
<A NAME="RA34003ST-10A">10a</A>
Bertrand MP.
Feray L.
Nouguier R.
Stella L.
Synlett
1998,
780
<A NAME="RA34003ST-10B">10b</A>
Bertrand MP.
Feray L.
Nouguier R.
Perfetti P.
Synlett
1999,
1148
<A NAME="RA34003ST-10C">10c</A>
Bertrand MP.
Feray L.
Nouguier R.
Perfetti P.
J. Org. Chem.
1999,
64:
9189
<A NAME="RA34003ST-11A">11a</A>
Friestad GK.
Qin J.
J. Am. Chem. Soc.
2000,
122:
8329
<A NAME="RA34003ST-11B">11b</A>
Friestad GK.
Qin J.
J. Am. Chem. Soc.
2001,
123:
9922
<A NAME="RA34003ST-11C">11c</A>
Friestad GK.
Shen Y.
Ruggles EL.
Angew. Chem. Int. Ed.
2003,
42:
5061
<A NAME="RA34003ST-12A">12a</A> For a review see:
Miyabe H.
Miyata O.
Naito T.
J. Synth. Org. Chem. Jpn.
2002,
60:
1087
<A NAME="RA34003ST-12B">12b</A>
Naito T.
Tajiri K.
Harimoto T.
Ninomiya I.
Kiguchi T.
Tetrahedron Lett.
1994,
35:
2205
<A NAME="RA34003ST-12C">12c</A>
Miyabe H.
Torieda M.
Kiguchi T.
Naito T.
Synlett
1997,
580
<A NAME="RA34003ST-12D">12d</A>
Miyabe H.
Torieda M.
Inoue K.
Tajiri K.
Kiguchi T.
Naito T.
J. Org. Chem.
1998,
63:
4397
<A NAME="RA34003ST-12E">12e</A>
Miyabe H.
Kanehira S.
Kume K.
Kandori H.
Naito T.
Tetrahedron
1998,
54:
5883
<A NAME="RA34003ST-12F">12f</A>
Miyata O.
Muroya K.
Koide J.
Naito T.
Synlett
1998,
271
<A NAME="RA34003ST-12G">12g</A>
Naito T.
Nakagawa K.
Nakamura T.
Kasei A.
Ninomiya I.
Kiguchi T.
J. Org. Chem.
1999,
64:
2003
<A NAME="RA34003ST-12H">12h</A>
Naito T.
Fukumoto D.
Takebayashi K.
Kiguchi T.
Heterocycles
1999,
51:
489
<A NAME="RA34003ST-12I">12i</A>
Kiguchi T.
Tajiri K.
Ninomiya I.
Naito T.
Tetrahedron
2000,
56:
5833
<A NAME="RA34003ST-12J">12j</A>
Miyabe H.
Nishiki A.
Naito T.
Chem. Pharm. Bull.
2003,
51:
100
<A NAME="RA34003ST-13">13</A> For examples employing Lewis acid in radical reactions:
Sibi MP.
Ji J.
Angew. Chem., Int. Ed. Engl.
1997,
36:
274 ; and references cited therein
<A NAME="RA34003ST-14">14</A>
Ueda M.
Miyabe H.
Namba M.
Nakabayashi T.
Naito T.
Tetrahedron Lett.
2002,
43:
4369
For selected examples see:
<A NAME="RA34003ST-15A">15a</A>
Hagiwara E.
Fujii A.
Sodeoka M.
J. Am. Chem. Soc.
1998,
120:
2474
<A NAME="RA34003ST-15B">15b</A>
Ferraris D.
Young B.
Dudding T.
Lectka T.
J. Am. Chem. Soc.
1998,
120:
4548
<A NAME="RA34003ST-15C">15c</A>
Davis FA.
McCoull W.
J. Org. Chem.
1999,
64:
3396
<A NAME="RA34003ST-16A">16a</A>
Fiaud J.-C.
Kagan HB.
Tetrahedron Lett.
1970,
1813
<A NAME="RA34003ST-16B">16b</A>
Fiaud J.-C.
Kagan HB.
Tetrahedron Lett.
1971,
1019
<A NAME="RA34003ST-16C">16c</A>
Yamamoto Y.
Ito W.
Tetrahedron
1988,
44:
5415
<A NAME="RA34003ST-16D">16d</A>
Kolasa T.
Sharma SK.
Miller MJ.
Tetrahedron
1988,
44:
5431
<A NAME="RA34003ST-17A">17a</A>
Hanessian S.
Yang R.-Y.
Tetrahedron Lett.
1996,
37:
5273
<A NAME="RA34003ST-17B">17b</A>
Hanessian S.
Yang R.-Y.
Tetrahedron Lett.
1996,
37:
8997
<A NAME="RA34003ST-17C">17c</A>
Hanessian S.
Lu P.-P.
Sancéau J.-Y.
Chemla P.
Gohda K.
Fonne-Pfister R.
Prade L.
Cowan-Jacob SW.
Angew. Chem. Int. Ed.
1999,
38:
3160
<A NAME="RA34003ST-18A">18a</A>
Hallett DJ.
Thomas EJ.
J. Chem. Soc., Chem. Commun.
1995,
657
<A NAME="RA34003ST-18B">18b</A>
Hallett DJ.
Thomas EJ.
Tetrahedron: Asymmetry
1995,
6:
2575
<A NAME="RA34003ST-18C">18c</A>
Bradley GW.
Hallett DJ.
Thomas EJ.
Tetrahedron: Asymmetry
1995,
6:
2579
<A NAME="RA34003ST-19A">19a</A>
Yamamoto Y.
Ito W.
Maruyama K.
J. Chem. Soc., Chem. Commun.
1985,
1131
<A NAME="RA34003ST-19B">19b</A>
Yamamoto Y.
Nishii S.
Maruyama K.
Komatsu T.
Ito W.
J. Am. Chem. Soc.
1986,
108:
7778
<A NAME="RA34003ST-19C">19c</A>
Petasis NA.
Zavialov IA.
J. Am. Chem. Soc.
1997,
119:
445
<A NAME="RA34003ST-19D">19d</A>
Petasis NA.
Goodman A.
Zavialov IA.
Tetrahedron
1997,
53:
16463
<A NAME="RA34003ST-20">20</A>
Miyabe H.
Ushiro C.
Ueda M.
Yamakawa K.
Naito T.
J. Org. Chem.
2000,
65:
176
<A NAME="RA34003ST-21">21</A>
Miyabe H.
Ueda M.
Naito T.
Chem. Commun.
2000,
2059
<A NAME="RA34003ST-22A">22a</A>
Miyabe H.
Ueda M.
Yoshioka N.
Naito T.
Synlett
1999,
465
<A NAME="RA34003ST-22B">22b</A>
Miyabe H.
Ueda M.
Yoshioka N.
Yamakawa K.
Naito T.
Tetrahedron
2000,
56:
2413
<A NAME="RA34003ST-23A">23a</A>
Kita Y.
Sato A.
Yamaguchi T.
Oka M.
Gotanda K.
Matsugi M.
Tetrahedron Lett.
1997,
38:
3549
<A NAME="RA34003ST-23B">23b</A>
Kita Y.
Gotanda K.
Murata K.
Suemura M.
Sato A.
Yamaguchi T.
Oka M.
Matsugi M.
Org. Proc. Res. Dev.
1998,
2:
250
<A NAME="RA34003ST-24">24</A>
Miyabe H.
Yamakawa K.
Yoshioka N.
Naito T.
Tetrahedron
1999,
55:
11209
<A NAME="RA34003ST-25">25</A>
Ryu I.
Araki F.
Minakata S.
Komatsu M.
Tetrahedron Lett.
1998,
39:
6335
<A NAME="RA34003ST-26A">26a</A>
Jezewski A.
Chajewska K.
Wielogórski Z.
Jurczak J.
Tetrahedron: Asymmetry
1997,
8:
1741
<A NAME="RA34003ST-26B">26b</A>
Bauer T.
Tetrahedron: Asymmetry
1996,
7:
981
<A NAME="RA34003ST-26C">26c</A>
Bauer T.
Chapuis C.
Jezewski A.
Kozak J.
Jurczak J.
Tetrahedron: Asymmetry
1996,
7:
1391
<A NAME="RA34003ST-27A">27a</A>
Miyabe H.
Fujii K.
Naito T.
Org. Lett.
1999,
1:
569
<A NAME="RA34003ST-27B">27b</A>
Miyabe H.
Fujii K.
Naito T.
Org. Biomol. Chem.
2003,
1:
381
<A NAME="RA34003ST-28A">28a</A>
Becker DA.
J. Am. Chem. Soc.
1996,
118:
905
<A NAME="RA34003ST-28B">28b</A>
Park Y.-T.
Kim K.-W.
J. Org. Chem.
1998,
63:
4494
Silylnitronates and nitroalkyl anions have been used as radical acceptors:
<A NAME="RA34003ST-29A">29a</A>
Branchaud BP.
Yu G.-X.
Tetrahedron Lett.
1991,
32:
3639
<A NAME="RA34003ST-29B">29b</A>
Kim S.
Yoon J.-Y.
Lim CJ.
Synlett
2000,
1151
<A NAME="RA34003ST-30">30</A>
Ueda M.
Miyabe H.
Teramachi M.
Miyata O.
Naito T.
Chem. Commun.
2003,
426
<A NAME="RA34003ST-31">31</A> For an example of the reaction of nitrones with triethylborane see:
Hollis WG.
Smith PL.
Hood DK.
Cook SM.
J. Org. Chem.
1994,
59:
3485
<A NAME="RA34003ST-32">32</A>
Garner PP.
Parker DT.
Gajewski JJ.
Lubineau A.
Angé J.
Queneau Y.
Beletskaya IP.
Cheprakov AV.
Fringuelli F.
Piermatti O.
Pizzo F.
Kobayashi S.
Organic Synthesis in Water
Grieco PA.
Blackie Academic & Professional;
London:
1998.
For reviews see:
<A NAME="RA34003ST-33A">33a</A>
Li CJ.
Chem. Rev.
1993,
93:
2023
<A NAME="RA34003ST-33B">33b</A>
Lubineau A.
Angé J.
Queneau Y.
Synthesis
1994,
741
<A NAME="RA34003ST-33C">33c</A>
Li CJ.
Tetrahedron
1996,
52:
5643
Triethylborane-mediated radical reactions in aqueous media see:
<A NAME="RA34003ST-34A">34a</A>
Yamazaki O.
Togo H.
Nogami G.
Yokoyama M.
Bull. Chem. Soc. Jpn.
1997,
71:
2519
<A NAME="RA34003ST-34B">34b</A>
Yorimitsu H.
Nakamura T.
Shinokubo H.
Oshima K.
J. Org. Chem.
1998,
63:
8604
<A NAME="RA34003ST-34C">34c</A>
Nakamura T.
Yorimitsu H.
Shinokubo H.
Oshima K.
Synlett
1998,
1351
<A NAME="RA34003ST-34D">34d</A>
Kita Y.
Nambu H.
Ramesh NG.
Anikumar G.
Matsugi M.
Org. Lett.
2001,
3:
1157
<A NAME="RA34003ST-35A">35a</A>
Posner GH.
Chem. Rev.
1986,
86:
831
<A NAME="RA34003ST-35B">35b</A>
Tempest PA.
Brown SD.
Armstrong RW.
Angew. Chem., Int. Ed. Engl.
1996,
35:
640
For reviews see:
<A NAME="RA34003ST-36A">36a</A>
Balkenhohl F.
von dem Bussche-Hünnefeld C.
Lansky A.
Zechel C.
Angew. Chem., Int. Ed. Engl.
1996,
35:
2288
<A NAME="RA34003ST-36B">36b</A>
Thompson LA.
Ellman JA.
Chem. Rev.
1996,
96:
555
<A NAME="RA34003ST-36C">36c</A>
Acc. Chem. Res.
1996,
29:
112-170 ; all of issue 3
<A NAME="RA34003ST-36D">36d</A>
Chem. Rev.
1997,
97:
347-510 ; all of issue 2
<A NAME="RA34003ST-36E">36e</A>
Hermkens PHH.
Ottenheijm HCJ.
Rees DC.
Tetrahedron
1997,
53:
5643
<A NAME="RA34003ST-36F">36f</A>
Brown RCD.
J. Chem. Soc., Perkin Trans. 1
1998,
3293
<A NAME="RA34003ST-37">37</A>
Miyabe H.
Yoshioka N.
Ueda M.
Naito T.
J. Chem. Soc., Perkin Trans. 1
1998,
3659
<A NAME="RA34003ST-38">38</A>
Miyabe H.
Ueda M.
Naito T.
J. Org. Chem.
2000,
65:
5043
For some recent examples see:
<A NAME="RA34003ST-39A">39a</A>
Backhaus D.
Tetrahedron Lett.
2000,
41:
2087
<A NAME="RA34003ST-39B">39b</A>
Lu W.
Chan TH.
J. Org. Chem.
2000,
65:
8589
<A NAME="RA34003ST-39C">39c</A>
Jeevanandam A.
Ling YC.
Tetrahedron Lett.
2001,
42:
4361
<A NAME="RA34003ST-39D">39d</A>
Lavilla B.
Coll O.
Bosch J.
Orozco M.
Luque FJ.
Eur. J. Org. Chem.
2001,
3719
<A NAME="RA34003ST-39E">39e</A>
Márquez F.
Montoro R.
Llebaria A.
Lago E.
Molins E.
Delgado A.
J. Org. Chem.
2002,
67:
308
<A NAME="RA34003ST-39F">39f</A>
Yadav JS.
Srinivas C.
Tetrahedron Lett.
2002,
43:
3837
<A NAME="RA34003ST-39G">39g</A>
Estevam IHS.
Bieber LW.
Tetrahedron Lett.
2003,
44:
667
<A NAME="RA34003ST-40A">40a</A>
Mattes H.
Benezra C.
Tetrahedron Lett.
1985,
26:
5697
<A NAME="RA34003ST-40B">40b</A>
Petrier C.
Dupuy C.
Luche JL.
Tetrahedron Lett.
1986,
27:
3149
<A NAME="RA34003ST-40C">40c</A>
Giese B.
Damm W.
Roth M.
Zehnder M.
Synlett
1992,
441
<A NAME="RA34003ST-40D">40d</A>
Erdmann P.
Schäfer J.
Springer R.
Zeitz H.-G.
Giese B.
Helv. Chim. Acta
1992,
75:
638
<A NAME="RA34003ST-40E">40e</A>
Bieber LW.
Malvestiti I.
Storch EC.
J. Org. Chem.
1997,
62:
9061
<A NAME="RA34003ST-40F">40f</A>
Huang T.
Keh CCK.
Li CJ.
Chem. Commun.
2002,
2440
<A NAME="RA34003ST-40G">40g</A>
Suàrez RM.
Sestelo JP.
Sarandeses LA.
Synlett
2002,
1435
<A NAME="RA34003ST-41">41</A>
Ueda M.
Miyabe H.
Nishimura A.
Sugino H.
Naito T.
Tetrahedron: Asymmetry
2003,
14:
2857
<A NAME="RA34003ST-42A">42a</A>
Miyabe H.
Ueda M.
Nishimura A.
Naito T.
Org. Lett.
2002,
4:
131
<A NAME="RA34003ST-42B">42b</A>
Miyabe H.
Nishimura A.
Ueda M.
Naito T.
Chem. Commun.
2002,
1454
<A NAME="RA34003ST-42C">42c</A>
Ueda M.
Miyabe H.
Nishimura A.
Miyata O.
Takemoto Y.
Naito T.
Org. Lett.
2003,
5:
2835
<A NAME="RA34003ST-43">43</A>
Routledge A.
Abell C.
Balasubramanian S.
Synlett
1997,
61
<A NAME="RA34003ST-44A">44a</A>
Du X.
Armstrong RW.
J. Org. Chem.
1997,
62:
5678
<A NAME="RA34003ST-44B">44b</A>
Du X.
Armstrong RW.
Tetrahedron Lett.
1998,
39:
2281
<A NAME="RA34003ST-45A">45a</A>
Berteina S.
De Mesmaeker A.
Tetrahedron Lett.
1998,
39:
5759
<A NAME="RA34003ST-45B">45b</A>
Berteina S.
Wendeborn S.
De Mesmaeker A.
Synlett
1998,
1231
<A NAME="RA34003ST-46">46</A>
Watanabe Y.
Ishikawa S.
Takao G.
Tour T.
Tetrahedron Lett.
1999,
40:
4535
<A NAME="RA34003ST-47">47</A>
Caddick S.
Hamza D.
Wadman SN.
Tetrahedron Lett.
1999,
40:
7285
<A NAME="RA34003ST-48">48</A>
Zhu X.
Ganesan A.
J. Comb. Chem.
1999,
1:
157
<A NAME="RA34003ST-49">49</A>
Enholm EJ.
Gallagher ME.
Jiang S.
Batson WA.
Org. Lett.
2002,
2:
1443
<A NAME="RA34003ST-50">50</A>
Sibi MP.
Chandramouli SV.
Tetrahedron Lett.
1997,
38:
8929
For reviews see:
<A NAME="RA34003ST-51A">51a</A>
Miyabe H.
Yakugaku Zasshi
2000,
120:
667
<A NAME="RA34003ST-51B">51b</A>
Naito T.
Miyabe H.
J. Synth. Org. Chem. Jpn.
2002,
60:
484
<A NAME="RA34003ST-52A">52a</A>
Miyabe H.
Fujishima Y.
Naito T.
J. Org. Chem.
1999,
64:
2174
<A NAME="RA34003ST-52B">52b</A>
Miyabe H.
Nishimura A.
Fujishima Y.
Naito T.
Tetrahedron
2003,
59:
1901
<A NAME="RA34003ST-53">53</A>
Wang and TentaGel OH resins purchased from Novabiochem were used in all experiments.
Unpublished results. For the discussions see:
<A NAME="RA34003ST-54A">54a</A>
Fitch WL.
Detre G.
Holmes CP.
Shoolery JN.
Keifer PA.
J. Org. Chem.
1994,
59:
7955
<A NAME="RA34003ST-54B">54b</A>
Keifer PA.
J. Org. Chem.
1996,
61:
1558
<A NAME="RA34003ST-55A">55a</A>
Miyabe H.
Konishi C.
Naito T.
Org. Lett.
2000,
2:
1443
<A NAME="RA34003ST-55B">55b</A>
Miyabe H.
Konishi C.
Naito T.
Chem. Pharm. Bull.
2003,
51:
540
<A NAME="RA34003ST-56">56</A>
Miyabe H.
Tanaka H.
Naito T.
Tetrahedron Lett.
1999,
40:
8387
<A NAME="RA34003ST-57">57</A>
Miyabe H.
Fujii K.
Tanaka H.
Naito T.
Chem. Commun.
2001,
831
<A NAME="RA34003ST-58">58</A> For study on the intramolecular reactions of alkoxycarbonyl-stabilized radicals
with electron rich alkene acceptor see:
Russell GA.
Li C.
Tetrahedron Lett.
1996,
37:
2557
<A NAME="RA34003ST-59A">59a</A>
Miyabe H.
Fujii K.
Goto T.
Naito T.
Org. Lett.
2000,
2:
4071
<A NAME="RA34003ST-59B">59b</A>
Miyabe H.
Ueda M.
Fujii K.
Nishimura A.
Naito T.
J. Org. Chem.
2003,
68:
5618
The reaction between Et3B and the radical in α-position to an ester is less effective than the corresponding
reaction of the radical deriving from ketones and aldehydes. For the discussions see:
<A NAME="RA34003ST-60A">60a</A>
Ollivier C.
Renaud P.
Angew. Chem. Int. Ed.
2000,
39:
925
<A NAME="RA34003ST-60B">60b</A>
Brown HC.
Negishi E.
J. Am. Chem. Soc.
1971,
93:
3777
<A NAME="RA34003ST-60C">60c</A>
Beraud V.
Gnanou Y.
Walton JC.
Maillard B.
Tetrahedron Lett.
2000,
41:
1195
