References and Notes
1
Weber US.
Steffen B.
Siegers CP.
Res. Commun. Mol. Pathol. Pharmacol.
1998,
99:
193
2a
Ptail AD.
Freyer AJ.
Drake SE.
Haltiwanger RC.
Bean MF.
Taylor PB.
Caranfa MJ.
Breen AL.
Bartus HR.
Johnson RK.
Hertzberg RP.
Westley JW.
J. Med. Chem.
1993,
36:
4131
2b
Zhao H.
Neamati N.
Hong HX.
Mazumder A.
Wang SM.
Sunder S.
Milne GWA.
Pommier Y.
Burke TB.
J. Med. Chem.
1997,
40:
242
3
Yun BS.
Lee IK.
Ryoo IJ.
Yoo ID.
J. Nat. Prod.
2001,
64:
1238
4a
Cheng JF.
Ishikawa A.
Ono Y.
Arrhenius T.
Nadzan A.
Bioorg. Med. Chem.
2003,
13:
3647
4b
Cheng JF.
Chen M.
Wallace D.
Tith S.
Arrhenius T.
Kashiwagi H.
Ono Y.
Ishikawa A.
Sato H.
Kozono T.
Ato H.
Nadzan AM.
Bioorg. Med. Chem. Lett.
2004,
14:
2411
5
Zaha AA.
Hazem A.
Microbiologica
2002,
25:
213
6
Whittaker M.
Floyd CD.
Brown P.
Gearing AJH.
Chem. Rev.
1999,
99:
2735
7
Maly DJ.
Leonetti F.
Backes BJ.
Dauber DS.
Harris JL.
Craik CS.
Ellman JA.
J. Org. Chem.
2002,
67:
910
8a
Quin LD.
A Guide to Organophosphorus Chemistry
Wiley-Interscience;
New York:
2000.
8b
Phosphorous-Carbon Heterocyclic Chemistry: The Rise of a New Domain
Mathey F.
Pergamon;
New York:
2001.
8c
McReynolds MD.
Dougherty JM.
Hanson PR.
Chem. Rev.
2004,
104:
2239
9
Li XS.
Zhang DW.
Pang H.
Shen F.
Fu H.
Jiang YY.
Zhao YF.
Org. Lett.
2005,
7:
4919
10a
Knochel P.
Singer RD.
Chem. Rev.
1993,
93:
2117
10b
Huo S.
Org. Lett.
2003,
5:
423
11a
Erdik E.
Tetrahedron
1984,
40:
641
11b
Knochel P.
Singer RD.
Chem. Rev.
1993,
93:
2117
12
Ikegami R.
Koresawa A.
Shibata T.
Takagi K.
J. Org. Chem.
2003,
68:
2195
13 Analytical data of 4-benzyl-2-ethoxy-3-phenylphospha-coumarin (4a) and 4-allyl-3-(4′-chlorophenyl)-2-ethoxy-phosphacoumarin (4g) (Figure
[1]
).
4a White foam; yield: 72%. 1H NMR (300 MHz, CDCl3): δ = 1.17 (t, 3
J = 7.2 Hz, 3 H, CH2CH3), 4.07 (m, 4 H, CH2CH3, PhCH2), 7.12-7.40 (m, 14 H, ArH). 13C NMR (75 MHz, CDCl3): δ = 16.4 (d, 3
J
P-C = 5.7 Hz, POCH2CH3), 36.0 (d, 3
J
P-C = 15.1 Hz, PhCH2), 63.9 (d, 2
J
P-C = 6.5 Hz, POCH2CH3), 119.4-138.4 (ArC), 146.6 (C-4), 150.9 (d, 2
J
P-C = 7.2 Hz, C-8a). 31P NMR (125 MHz, CDCl3): δ = 8.57. HRMS: m/z calcd for C23H22PO3 [M + H]+, 377.1307; found: 377.1304.
4g Yellowish viscous oil; yield: 85%. 1H NMR (300 MHz, CDCl3): δ = 1.17 (t, 3
J = 7.2 Hz, 3 H, CH2CH3), 3.32 (m, 2 H, CH2=CHCH2), 4.08 (m, 2 H, OCH2CH3), 4.95-5.12 (dd, 2 H, CH2=CHCH2), 5.84 (m, 1 H, CH2=CHCH2), 7.18-7.57 (m, 8 H, ArH). 13C NMR (75 MHz, CDCl3): δ = 16.4 (d, 3
J
P-C = 6.5 Hz, POCH2CH3), 34.2 (d, 3
J
P-C = 15.10 Hz, CH2=CHCH2), 63.8 (d, 2
J
P-C = 6.5 Hz, POCH2CH3), 117.8-134.5 (ArC, CH2=CH), 147.2 (C-4), 150.8 (C-8a). 31P NMR (125 MHz, CDCl3): δ = 8.13. HRMS: m/z calcd for C19H19PO3Cl [M + H]+: 361.0760; found: 361.0753.
Organozinc Reagents; General Procedure
Zn powder was treated with 1 M HCl for 10 min, washed with acetone and then dried under vacuum before use. A mixture of Zn powder (3.0 mmol) and TMSCl (0.5 mL) in THF (10 mL) was stirred under a nitrogen atmosphere at r.t. for 20 min, and then heated to 55-65 °C (Table
[1]
). Alkyl or aryl halide (3, 2.0 mmol) in anhyd THF (2 mL) was added dropwise, and the reaction was maintained at this temperature for 10-24 h. The resulting solution was cooled to r.t., and the clear liquid could be directly used for the following reaction.
Negishi Cross-Coupling Reaction of Organozinc Reagents with 4-Tosylphosphacoumarins General Procedure
A mixture of 4-tosylphosphacoumarin (1) (1.0 mmol), Pd(PPh3)4 (0.05 mmol), PPh3 (0.05 mmol) and the organozinc reagent prepared above in anhyd THF (10 mL) was heated to 55 °C under a nitrogen atmosphere. After 2-8 h, the reaction mixture was cooled to r.t. After the solvent was removed under reduced pressure, H2O (10 mL) was added to the residue, the solution was extracted with CH2Cl2 (3 × 5 mL), and the combined organic phase was dried over anhyd Na2SO4. After removal of the solvent, the residue was purified by column chromatography on silica gel (PE-EtOAc, 2:1) to give product 2.
