Synlett 2006(15): 2435-2438  
DOI: 10.1055/s-2006-950400
LETTER
© Georg Thieme Verlag Stuttgart · New York

Palladium-Catalyzed Regio- and Diastereoselective Allylic Alkylation with Azlactones Using Triphenylarsine

Motoi Kawatsura*a, Daiji Ikedab, Tamiko Ishiib, Yuji Komatsua, Junichi Uenishib
a Department of Materials Science, Faculty of Engineering, Tottori University, Koyama, Tottori 680-8552, Japan
b Kyoto Pharmaceutical University, Misasagi, Yamashina, Kyoto 607-8412, Japan
Fax: +81(857)315179; e-Mail: kawatsur@chem.tottori-u.ac.jp;
Further Information

Publication History

Received 15 June 2006
Publication Date:
08 September 2006 (online)

Abstract

The palladium-catalyzed regio- and diastereoselective allylic alkylation of (R)-2-acetoxy-4-phenyl-3-butene with azlactones using AsPh3 successfully occurred. The stereochemistries were highly controlled, and the reaction produced a coupling product which possessed vicinal chiral quaternary and tertiary carbon centers.

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Methyl (2 R ,3 R )-2-Benzamido-2,3-dimethyl-5-phenyl-4-pentenoate [(2 R ,3 R )-6a]: R f = 0.36 (20% EtOAc in hexane); [α]D 26 87.6 (c = 1.0, CHCl3). 1H NMR (400 MHz, CDCl3): δ = 7.16-7.64 (m, 10 H), 6.80 (s, 1 H), 6.59 (d, J = 15.7 Hz, 1 H), 6.09 (dd, J = 9.9, 15.7 Hz, 1 H), 3.72 (s, 3 H), 2.98 (dq, J = 6.6, 9.9 Hz, 1 H), 1.58 (s, 3 H), 1.03 (d, J = 6.6 Hz, 3 H). 13C NMR (100 MHz, CDCl3): δ = 173.7, 165.9, 136.5, 134.2, 133.2, 131.5, 129.7, 128.6, 128.5, 127.8, 126.7, 126.3, 62.0, 52.5, 44.4, 17.8, 16.0. MS (EI): m/z = 337. HRMS (EI): m/z calcd for C21H23NO3: 337.1678; found: 337.1677.
Methyl (2 S ,3 R )-2-Benzamido-2,3-dimethyl-5-phenyl-4-pentenoate [2 S ,3 R )-6a]: R f = 0.36 (20% EtOAc in hexane); [α]D 26 80.9 (c = 1.0, CHCl3). 1H NMR (400 MHz, CDCl3): δ = 7.14-7.69 (m, 10 H), 6.77 (s, 1 H), 6.45 (d, J = 15.7 Hz, 1 H), 6.10 (dd, J = 9.3, 15.7 Hz, 1 H), 3.72 (s, 3 H), 2.93 (dq, J = 7.0, 9.3 Hz, 1 H), 1.73 (s, 3 H), 1.15 (d, J = 7.0 Hz, 3 H). 13C NMR (100 MHz, CDCl3): δ = 173.2, 166.6, 136.7, 134.5, 132.3, 131.4, 130.1, 128.5, 128.4, 127.5, 126.8, 126.2, 62.5, 52.3, 45.0, 20.5, 15.6. MS (EI): m/z = 337. HRMS (EI): m/z calcd for C21H23NO3: 337.1678; found: 337.1669.