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Synlett 2005(19): 2963-2967  
DOI: 10.1055/s-2005-918963
LETTER
© Georg Thieme Verlag Stuttgart · New York

Phosphinite Thioglycosides Derived from Natural d-Sugars as Useful P/S Ligands for the Synthesis of Both Enantiomers in Palladium-Catalyzed Asymmetric Substitution

Noureddine Khiar*a, Belén Suáreza, Victoria Valdiviab, Inmaculada Fernández*b
a Instituto de Investigaciones Químicas, C.S.I.C-Universidad de Sevilla, c/. Américo Vespucio 49, Isla de la Cartuja, 41092 Sevilla, Spain
Fax: +34(95)4460565; e-Mail: khiar@iiq.csic.es;
b Departamento de Química Orgánica y Farmacéutica, Facultad de Farmacia, Universidad de Sevilla, c/ Profesor García González 2, 41012 Sevilla, Spain
e-Mail: inmaff@us.es;
Further Information

Publication History

Received 18 July 2005
Publication Date:
27 October 2005 (online)

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Abstract

Phosphinite thioglycosides I for which a modular ­synthetic approach is reported, were found highly efficient catalyst precursors for palladium(0)-catalyzed asymmetric substitution. Both enantiomers of the allylated products have been obtained with high ee (up to 96%) using natural sugars as catalyst precursors.

Key words

P/S ligands - carbohydrates - both enantiomers - allylic substitution

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This work has been presented in part in the ISOCS-XXI, Madrid, Spain, 4-9 July 2004.

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Compound 12: 1H NMR (500 MHz, CDCl3): δ = 7.60-7.50 (m, 4 H), 7.38 -7.31 (m, 6 H), 7.21 (d, 2 H, J = 7.9 Hz), 7.02 (d, 2 H, J = 8.0 Hz), 4.58 (d, 1 H, J = 10.0 Hz), 4.35 (dd, 1 H, J = 4.5, 11.7 Hz), 4.29 (dd, 1 H, J = 7.7, 11.7 Hz), 4.23 (t, 1 H, J = 5.9 Hz), 4.13 (d, 1 H, J = 5.5 Hz), 4.02-3.93 (m, 2 H), 2.30 (s, 3 H), 1.43 (s, 3 H), 1.29 (s, 3 H), 1.19 (s, 9 H) ppm. 13C NMR (125 MHz, CDCl3): δ = 178.3, 137.7, 132.4, 131.1 (d, J PC = 11.8 Hz), 130.7 (d, J PC = 11.8 Hz), 129.3 (d, J PC = 26.0 Hz), 128.1 (d, J PC = 6.8 Hz), 110.5, 88.4 (d, J PC = 4.1 Hz), 80.4 (d, J PC = 28.4 Hz), 79.1, 74.0, 73.7, 63.7, 38.7, 27.8, 27.1, 26.4, 21.2 ppm. 31P NMR (121.4 MHz, CDCl3): δ = 119.5 ppm.
Compound 13: 1H NMR (500 MHz, CDCl3): δ = 7.58-7.49 (m, 4 H), 7.36-7.32 (m, 6 H), 7.23 (d, 2 H, J = 7.9 Hz), 7.03 (d, 2 H, J = 7.9 Hz), 4.56 (d, 1 H, J = 9.4 Hz), 4.33 (d, 2 H, J = 6.1 Hz), 4.23 (t, 1 H, J = 5.9 Hz), 4.13 (dd, 1 H, J = 5.5, 1.5 Hz), 4.03-3.91 (m, 2 H), 2.31 (s, 3 H), 2.07 (s, 3 H), 1.41 (s, 3 H), 1.28 (s, 3 H) ppm. 13C NMR (125 MHz, CDCl3): δ = 170.8, 142.6 (d, J PC = 18.5 Hz), 141.9 (d, J PC = 15.4 Hz), 137.7, 132.6, 130.9 (d, J PC = 21.8 Hz), 130.8 (d, J PC = 21.8 Hz), 130.2, 129.3 (d, J PC = 30.2 Hz), 128.1 (d, J PC = 6.9 Hz), 110.6, 87.9 (d, J PC = 4.2 Hz), 80.0 (d, J PC = 18.4 Hz), 79.1, 73.9, 73.6, 63.8, 27.7, 26.4, 21.1, 20.8 ppm. 31P NMR (121.4 MHz, CDCl3): δ = 119.4 ppm.
Compound 14: 1H NMR (500 MHz, CDCl3): δ = 7.57-7.50 (m, 4 H), 7.35-7.32 (m, 6 H), 5.56 (d, 1 H, J = 5.1 Hz), 4.70-4.67 (m, 1 H), 4.34-4.11 (m, 5 H), 2.02 (s, 3 H), 1.41 (s, 3 H), 1.30 (s, 12 H) ppm. 13C NMR (125 MHz, CDCl3): δ = 170.7, 141.8 (d, J PC = 19.4 Hz), 141.7 (d, J PC = 16.0 Hz), 130.9 (d, J PC = 21.8 Hz), 130.7 (d, J PC = 21.7 Hz), 129.3 (d, J PC = 2.7 Hz), 128.2 (d, J PC = 7.0 Hz), 128.1 (d, J PC = 7.0 Hz), 109.7, 81.3 (d, J PC = 5.6 Hz), 77.8 (d, J PC = 18.8 Hz), 75.6 (d, J PC = 5.0 Hz), 73.8, 66.6, 63.5, 43.8, 31.3, 27.9, 26.3, 20.8 ppm. 31P NMR (121.4 MHz, CDCl3): δ = 117.5 ppm.
Compound 15: 1H NMR (500 MHz, CDCl3): δ = 7.56-7.47 (m, 4 H), 7.34-7.29 (m, 6 H), 4.51 (d, 1 H, J = 9.5 Hz), 4.33-4.26 (m, 3 H), 4.15 (dd, 1 H, J = 1.8, 5.6 Hz), 3.96-3.88 (m, 2 H), 2.03 (s, 3 H), 1.42 (s, 3 H), 1.29 (s, 3 H), 1.22 (s, 9 H) ppm.13C NMR (125 MHz, CDCl3): δ = 170.8, 142.9 (d, J PC = 18.4 Hz), 142.1 (d, J PC = 15.2 Hz), 131.3 (d, J PC = 22.1 Hz), 130.5 (d, J PC = 21.3 Hz), 129.0 (d, J PC = 32.5 Hz), 128.0 (d, J PC = 6.4 Hz), 127.9 (d, J PC = 7.2 Hz), 110.5, 83.1 (d, J PC = 3.3 Hz), 80.6 (d, J PC = 18.7 Hz), 79.3 (d, J PC = 2.7 Hz), 73.6 (2 C), 63.9, 44.1, 31.3, 27.7, 26.4, 20.8 ppm. 31P NMR (121.4 MHz, CDCl3): δ = 119.8 ppm.
Compound 21: 1H NMR (500 MHz, CDCl3): δ = 7.54-7.46 (m, 4 H), 7.33-7.29 (m, 6 H), 4.76 (d, 1 H, J = 6.9 Hz), 4.28-4.26 (m, 1 H), 4.22 (t, 1 H, J = 5.7 Hz), 4.10-4.01 (m, 1 H), 3.70 (dd, 1 H, J = 4.4, 12.7 Hz), 1.47 (s, 3 H), 1.30 (s, 3 H), 1.19 (s, 9 H) ppm.13C NMR (125 MHz, CDCl3): δ = 131.2 (d, J PC = 22.1 Hz), 130.5 (d, J PC = 21.4 Hz), 129.1 (d, J PC = 31.7 Hz), 128.1 (d, J PC = 5.9 Hz), 128.0 (d, J PC = 6.7 Hz), 110.1, 84.5, 82.6 (d, J PC = 4.2 Hz), 80.3 (d, J PC = 19.2 Hz), 72.2, 63.2, 44.0, 31.3, 27.8, 26.3 ppm. 31P NMR (121.4 MHz, CDCl3): δ = 118.6 ppm.

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Typical Procedure.
To a solution of the ligand (4.3 mol%) in dry deoxygenated CH2Cl2 (0.5 mL), [PdCl(C3H5)]2 (1.5 mol%) was added under argon. The reaction mixture was stirred for 1 h at r.t., then a catalytic amount of KOAc (0.5 mg) was added, followed by BSA (3 mol equiv) and a solution of 1,3-diphenyl-2-propenyl acetate (16, 1 mol equiv) in dry deoxygenated CH2Cl2 (0.7 mL). The temperature was then adjusted to the desired one (see Table [1] ) and dimethyl malonate (3 equiv) was added. Once the reaction finished as judged by TLC, the solvent was evaporated and the residue purified by column chromatography, affording the desired product 17 as a viscous oil, which solidify on standing. The ee was determined by chiral HPLC using a Chiralpack AD column (1 mL/min, i-PrOH-hexane, 5:95, 30 °C). Retention times: (R)-17: t R = 14.2 min, (S)-17: t R = 19.5 min.