References
<A NAME="RS06002ST-1">1</A>
Mortreux A.
Blanchard M.
J. Chem. Soc, Chem. Commun.
1974,
786
For recent references, see:
<A NAME="RS06002ST-2A">2a</A>
Brizius G.
Bunz UHF.
Org. Lett.
2002,
4:
2829
<A NAME="RS06002ST-2B">2b</A>
Brizius G.
Kroth S.
Bunz UHF.
Macromolecules
2002,
35:
5317
<A NAME="RS06002ST-2C">2c</A> For reviews, see:
Bunz UHF.
Acc. Chem. Res.
2001,
34:
998
<A NAME="RS06002ST-2D">2d</A> See also:
Bunz UHF.
Kloppenburg L.
Angew.
Chem. Int. Ed.
1999,
38:
478
<A NAME="RS06002ST-2E">2e</A> For a pertinent example,
see:
Ge P.-H.
Fu W.
Herrmann WA.
Herdtweck E.
Campana C.
Adams RA.
Bunz UHF.
Angew. Chem.
Int. Ed.
2000,
39:
3607
For selected references, see:
<A NAME="RS06002ST-3A">3a</A>
Fürstner A.
Mathes C.
Grela K.
Chem.
Commun.
2002,
1057
<A NAME="RS06002ST-3B">3b</A>
Fürstner A.
Stelzer F.
Rumbo A.
Krause H.
Chem.-Eur.
J.
2002,
8:
1856
<A NAME="RS06002ST-3C">3c</A>
Fürstner A.
Mathes C.
Lehmann CW.
Chem.-Eur. J.
2001,
7:
5299
<A NAME="RS06002ST-3D">3d</A>
Fürstner A.
Grela K.
Mathes C.
Lehmann CW.
J. Am. Chem. Soc.
2000,
122:
11799
<A NAME="RS06002ST-3E">3e</A>
Fürstner A.
Guth O.
Rumbo A.
Seidel G.
J. Am. Chem. Soc.
1999,
121:
11108
<A NAME="RS06002ST-3F">3f</A>
Fürstner A.
Mathes C.
Lehmann CW.
J. Am. Chem. Soc.
1999,
121:
9453
<A NAME="RS06002ST-3G">3g</A>
Fürstner A.
Seidel G.
Angew. Chem.
Int. Ed.
1998,
37:
1734
For reviews, see:
<A NAME="RS06002ST-4A">4a</A>
Haley MM.
Synlett
1998,
557
<A NAME="RS06002ST-4B">4b</A>
Haley MM.
Pak JJ.
Brand SC.
Top. Curr. Chem.
1999,
202:
81
<A NAME="RS06002ST-4C">4c</A>
Haley MM.
Wan WB. In Advances in Strained and Interesting Organic
Molecules
Vol. 8:
Halton B.
JAI
Press;
New York:
2000.
p.1
<A NAME="RS06002ST-4D">4d</A>
Kennedy RD.
Lloyd D.
McNab H.
J.
Chem. Soc., Perkin Trans. 1
2002,
1601
<A NAME="RS06002ST-4E">4e</A>
Balaban AT.
Banciu M.
Ciorba V.
Annulenes, Benzo-, Hetero-, Homo-Derivatives and Their Valence Isomers
Vol.
2:
CRC Press;
Boca Raton:
1987.
p.146
<A NAME="RS06002ST-5">5</A>
Youngs WJ.
Tessier CA.
Bradshaw JD.
Chem. Rev.
1999,
99:
3153
For a review, see:
<A NAME="RS06002ST-6A">6a</A>
Bunz UHF.
Rubin Y.
Tobe Y.
Chem. Soc. Rev.
1999,
28:
107
<A NAME="RS06002ST-6B">6b</A> See also, inter alia:
Narita N.
Nagai S.
Suzuki S.
Phys. Rev. B: Condensed Matter Mater. Phys.
2002,
64:
245408
<A NAME="RS06002ST-6C">6c</A>
Kehoe JM.
Kiley JH.
English JJ.
Johnson CA.
Petersen RC.
Haley MM.
Org. Lett.
2000,
2:
969
<A NAME="RS06002ST-6D">6d</A>
Grima JN.
Evans KE.
Chem.
Commun.
2000,
1531
<A NAME="RS06002ST-7A">7a</A>
Boese R.
Matzger AJ.
Vollhardt KPC.
J. Am. Chem.
Soc.
1997,
119:
2052
<A NAME="RS06002ST-7B">7b</A>
Dosa PI.
Erben C.
Iyer VS.
Vollhardt KPC.
Wasser IM.
J. Am. Chem. Soc.
1999,
121:
10430
For selected recent references,
see:
<A NAME="RS06002ST-8A">8a</A>
Pak JJ.
Weakley TJR.
Haley MM.
Lau DYK.
Stoddart JF.
Synthesis
2002,
1256
<A NAME="RS06002ST-8B">8b</A>
Tobe Y.
Utsumi N.
Kawabata K.
Nagano A.
Adachi K.
Araki S.
Sonoda M.
Hirose K.
Naemura K.
J. Am. Chem.
Soc.
2002,
124:
5350
<A NAME="RS06002ST-8C">8c</A>
Hosokawa Y.
Kawase T.
Oda M.
Chem.
Commun.
2001,
1948
<A NAME="RS06002ST-8D">8d</A>
Nakamura K.
Okubo H.
Yamaguchi M.
Org.
Lett.
2001,
3:
1097
<A NAME="RS06002ST-8E">8e</A>
Höger S.
Enkelmann V.
Bonrad K.
Tschierske C.
Angew.
Chem. Int. Ed.
2000,
39:
2268
<A NAME="RS06002ST-8F">8f</A> See also:
Moore JS.
Acc. Chem. Res.
1997,
30:
402
<A NAME="RS06002ST-8G">8g</A>
Zhang J.
Pesak DJ.
Ludwick JL.
Moore JS.
J.
Am. Chem. Soc.
1994,
116:
4227
<A NAME="RS06002ST-8H">8h</A>
Pickholz M.
Stafström S.
Chem. Phys.
2001,
270:
245
See, inter alia:
<A NAME="RS06002ST-9A">9a</A>
Sarkar A.
Pak JJ.
Rayfield GW.
Haley MM.
J.
Mater. Chem.
2001,
11:
2943
<A NAME="RS06002ST-9B">9b</A>
Wan WB.
Haley MM.
J. Org. Chem.
2001,
66:
3893
<A NAME="RS06002ST-10">10</A>
Eickmeier C.
Junga H.
Matzger AJ.
Scherhag F.
Shim M.
Vollhardt KPC.
Angew.
Chem., Int. Ed. Engl.
1997,
36:
2103
Most of the starting iodoarenes
are either commercially available (5a, 5h, 5k) or have
been described previously:
<A NAME="RS06002ST-11A">11a</A>
5b, 5d:
Kryska A.
Skulski L.
J. Chem. Res., Synop.
1999,
590
<A NAME="RS06002ST-11B">11b</A>
5c:
Lacour J.
Monchaud D.
Bernardinelli G.
Favarger F.
Org.
Lett.
2001,
3:
1407
<A NAME="RS06002ST-11C">11c</A>
5g:
Nakayama J.
Sakai A.
Hoshino M.
J. Org. Chem.
1984,
49:
5084
<A NAME="RS06002ST-11D">11d</A>
5i:
Mattern DL.
J. Org. Chem.
1983,
48:
4772
<A NAME="RS06002ST-11E">11e</A>
5j:
Goldfinger MB.
Crawford KB.
Swager TM.
J.
Am. Chem. Soc.
1997,
119:
4578
<A NAME="RS06002ST-11F">11f</A>
1,2-Dibromo-4,5-diiodobenzene
(5e) was prepared using the general procedure
described for 5j. Compound 5e:
White needles (33%), mp 173-175 °C. 1H
NMR (400 MHz, CDCl3): δ = 8.03
(s, 2 H). 13C NMR (100 MHz, CDCl3): δ = 142.5, 125.4,
106.9. MS (EI, 70 eV): m/z (%) = 488
(100) [M+], 361 (32), 234
(17), 153 (8), 74 (20). IR (CS2): 2925, 1408, 1282, 1005,
877 cm-1. HRMS: Calcd for C6H2Br2I2:
487.6592. Found: 487.6596. Anal. Calcd for C6H2Br2I2:
C,
14.78; H, 0.41. Found: C, 14.55; H, 0.43.
1,4-Dibromo-2,3-diiodobenzene
(
5f): The first two steps followed
the general procedure in ref.
[11g]
.
Chloral hydrate (9.93 g, 60.0 mmol), 2,5-dibromoaniline (12.6 g,
50.0 mmol), hydroxylamine hydrochloride (5.21 g, 75.0 mmol), and
Na2SO4 (60.0 g) were suspended in a mixture
of H2O (300 mL) and EtOH (300 mL). The mixture was stirred
and kept at reflux for 12 h. It was then concentrated by evaporation
of the ethanol and poured onto crushed ice, which caused precipitation
of a white solid. After 5 h at 0 °C, the suspension
was filtered, and the crystals were air dried to yield 13.5 g (84%)
of crude 2,5-dibromoisonitroso-acetanilide. This amount was then
cyclized by heating at 100 °C in 86% H2SO4 for
15 min. The resulting dark red suspension was poured onto crushed
ice to yield 5.98 g (47%) of 3,6-dibromoisatine as bright
orange crystals, which were subsequently subjected to basic hydrolysis
in aq H2O2to yield 2.72 g (47%) of
off-white crystals of 3,6-dibromoanthranilic acid.
[11h]
Finally,
3,6-dibromoanthranilic acid was converted to 1,4-dibromo-2,3-diiodobenzene
by employing the aprotic diazotization procedure in ref.
[11i]
After column
chromatography(hexanes) the product was obtained as white crystals,
2.61 g (58%), mp 97-99 °C. 1H
NMR (400 MHz, CDCl3): δ = 7.49
(s, 2 H). 13C NMR (100 MHz, CDCl3): δ = 132.8,
127.8, 117.4. MS (EI, 70 eV): m/z (%) = 488
(100) [M+], 361 (29), 234
(21), 153 (18), 74 (24). IR (CHCl3): 2920,
1396, 1150, 1002, 810 cm-1. HRMS: Calcd for
C6H2Br2I2: 487.6592.
Found: 487.6596. Anal. Calcd for C6H2Br2I2:
C, 14.78; H, 0.41. Found: C, 14.74; H, 0.04.
<A NAME="RS06002ST-11G">11g</A>
Garden SJ.
Torres JC.
Ferreira AA.
Silva RB.
Pinto AC.
Tetrahedron Lett.
1997,
38:
1501
<A NAME="RS06002ST-11H">11h</A>
Lisowski V.
Robba M.
Rault S.
J.
Org. Chem.
2000,
65:
4193
<A NAME="RS06002ST-11I">11i</A>
Nakayama J.
Sakai A.
Hoshino M.
J.
Org. Chem.
1984,
49:
5084
<A NAME="RS06002ST-12">12</A>
General Procedure
for Propynylations: To a 150 mL Schlenk flask, equipped with
a Teflon-coated magnetic stirring bar, were added the diiodoarene
(1.67 mmol), PdCl2(PPh3)2 (177
mg, 0.25 mmol), CuI (32 mg, 0.17 mmol), and Et3N (7.50
mL). The flask was then evacuated and filled with propyne gas up
to 1.5 atm (approx. 10 mmol, 3 equiv) of pressure. Depending on
the system, the reaction mixture was stirred for 22-96
h, at either room or elevated temperatures (Table
[1]
). The reaction mixture
was then diluted with ether, washed with two portions of aq NH4Cl, and
dried over MgSO4. Solvent was removed in vacuo and the
resulting crude product purified by Kugelrohr distillation, sublimation,
or chromatography.
<A NAME="RS06002ST-13A">13a</A>
Sonogashira K. In Metal-Catalyzed
Cross-Coupling Reactions
Diederich F.
Stang PJ.
Wiley-VCH;
New
York:
1998.
p.Chap. 5
<A NAME="RS06002ST-13B">13b</A>
Sonogashira K. In Comprehensive Organic
Synthesis
Vol. 3:
Trost BM.
Pergamon;
New York:
1991.
p.Chap. 2.4
<A NAME="RS06002ST-14">14</A> A somewhat related application of
microwaves in Sonogashira reactions is described in:
Erdelyi M.
Gogoll A.
J. Org. Chem.
2001,
66:
4165
<A NAME="RS06002ST-15">15</A>
Lidström P.
Tierney J.
Wathey B.
Westman J.
Tetrahedron
2001,
57:
9225
<A NAME="RS06002ST-16">16</A>
General Procedure for Microwave-Assisted
Propynylations: A heavy-walled Smith process vial was charged with
a magnetic stirring bar, Et3N (0.9 mL), DMF (0.1 mL), PdCl2(PPh3)2 (19.6
mg, 0.028 mmol), CuI (5.4 mg, 0.028 mmol), and the dibromodiiodobenzene
(0.113 mmol). The vial was sealed, evacuated, and filled with propyne
through a Teflon septum up to 2.5 atm pressure. It was then irradiated in
a Smith Synthesizer single-mode microwave cavity, producing continuous
radiation at 2450 MHz. The resulting solution was immediately filtered
through a short plug of silica gel (hexanes/ethyl acetate)
to remove the catalyst and the crude product further purified by
column chromatography on silica gel (hexanes).
<A NAME="RS06002ST-17A">17a</A>
Iyoda M.
Vorasingha A.
Kuwatani Y.
Yoshida M.
Tetrahedron
Lett.
1998,
39:
4701
<A NAME="RS06002ST-17B">17b</A>
Huynh C.
Linstrumelle G.
Tetrahedron
1988,
44:
6337
<A NAME="RS06002ST-18">18</A>
Collman JP.
Hegedus LS.
Norton JR.
Finke RG.
Principles and Applications of Organotransition
Metal Chemistry
University Science Books;
Mill
Valley:
1987.
p.Chap. 9
<A NAME="RS06002ST-19">19</A>
General Procedure for (Me3CO)3WCCMe3-Mediated Alkyne
Metathesis: A 25 mL Schlenk flask was charged, under the atmosphere
of nitrogen, with the respective propynylated arene (0.20-0.35
mmol), (Me3CO)3WCCMe3 (20-40
mol%), and toluene (20 mL). The solution was stirred at
80 °C for 8-96 h (Table
[2]
). After the reaction was complete,
solvent was removed in vacuo, and the residue was subjected to flash
chromatography on silica, eluting with hexane/ethyl acetate.
Compound 1e: Brown crystals, showing green
fluorescence, mp 292-300 °C(dec). 1H
NMR (400 MHz, CDCl3): δ = 7.56
(s). MS (EI, 70 eV): m/z (%) = 774
(100)[M+], 695 (29), 614 (19).
IR (CHCl3): 2933, 2255, 1464,
1274, 1154 cm-1. The compound decomposed
upon standing for one week. Compound 2:
Pale yellow crystals, showing green fluorescence, mp 310-315 °C(dec). 1H
NMR (400 MHz, CDCl3): δ = 8.05
(br t, 2 H, J = 1.5
Hz), 7.59 (dd, 4 H, J
1
= 3.3
Hz, J
2
= 5.7
Hz), 7.54 (dd, 4 H, J
1
= 1.6
Hz, J
2
= 7.9
Hz), 7.38 (t, 2 H, J = 8.0
Hz), 7.32 (dd, 4 H, J
1
= 3.4 Hz, J
2
= 5.8
Hz). MS (EI, 70 eV): m/z (%) = 401(31) [M + H]+,
400(100) [M+], 199(11). HRMS:
Calcd for C32H16: 400.1252. Found: 400.1248.
UV/Vis (CH2Cl2): λmax (lg ) = 265
(4.03), 272 (4.05), 278 (4.11), 280 (4.10), 317 (3.62), 341 (3.26)
nm. IR (CHCl3): 2920, 2219,
1468, 1212,
892 cm-1. Selected
spectral data for 3: 1H
NMR (400 MHz, CDCl3): δ = 7.44
(AA′ m, 8 H), 7.34 (s, 2 H), 7.19 (BB′ m, 8 H).
MS (EI, 70 eV): m/z (%) = 524
(10) [M + 2H]+, 523 (42) [M + H]+,
522 (100) [M+], 261 (25) [M2+].
HRMS: Calcd for C42H18: 522.1408. Found: 522.1428.
<A NAME="RS06002ST-20">20</A> The spectral data are in good agreement
with those in:
Staab HA.
Graf F.
Chem. Ber.
1970,
103:
1107
<A NAME="RS06002ST-21">21</A>
The spectral data are in good agreement
with those in ref.
[17a]
<A NAME="RS06002ST-22">22</A>
Srinivasan M.
Sankararaman S.
Dix I.
Jones PG.
Org. Lett.
2000,
2:
3849
<A NAME="RS06002ST-23A">23a</A>
Alkorta I.
Rozas I.
Elguero J.
Tetrahedron
2001,
57:
6043
<A NAME="RS06002ST-23B">23b</A>
Jusélius J.
Sundholm D.
Phys. Chem.
2001,
3:
2433
<A NAME="RS06002ST-23C">23c</A>
Godard C.
Lepetit C.
Chauvin R.
Chem. Commun.
2000,
1833
<A NAME="RS06002ST-23D">23d</A>
Wan WB.
Kimball DB.
Haley MM.
Tetrahedron Lett.
1998,
39:
6795
<A NAME="RS06002ST-23E">23e</A>
Matzger AJ.
Vollhardt KPC.
Tetrahedron
Lett.
1998,
39:
6791
<A NAME="RS06002ST-24">24</A>
Details of the crystal structure determination
(deposition number CCDC 192630) may be obtained free of charge on application
to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK [Fax: +44(1223)336033;
E-mail: deposit@ccdc.cam.ac.uk].
