N-Benzyl-Protection
of Amino Acid Derivatives by Reductive Alkylation with α-Picoline-Borane

Yasushi Kawase; Takehiro Yamagishi; Teruo Kutsuma; Tadashi Kataoka; Kimio Ueda; Takeo Iwakuma; Tadashi Nakata; Tsutomu Yokomatsu

doi:10.1055/s-0029-1218707

PAPER

N-Benzyl-Protection of Amino Acid Derivatives by Reductive Alkylation with α-Picoline-Borane

Yasushi Kawase^a, Takehiro Yamagishi^a, Teruo Kutsuma^a, Tadashi Kataoka^b, Kimio Ueda^c, Takeo Iwakuma^c, Tadashi Nakata^d, Tsutomu Yokomatsu*^a
^a School of Pharmacy, Tokyo University of Pharmacy & Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Fax: +81(42)6763239; e-Mail: yokomatu@toyaku.ac.jp;
^b Yokohama College of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama, Kanagawa 245-0066, Japan
^c Development Laboratory, Junsei Chemical Co., LTD, 1-6 Ohmano-cho, Koshigaya, Saitama 343-0844, Japan
^d Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan

Abstract

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Abstract

A convenient method for N-protection of amino acid derivatives with a benzyl group by reductive alkylation of amino acid derivatives with α-picoline-borane is described. Amino acid esters or amino alcohols were treated with aryl aldehydes in methanol/acetic acid in the presence of α-picoline-borane to give N-benzyl-protected amino acid derivatives in good yields.

Key words

amino acid esters - amino alcohols - benzylation - protecting groups - reductions

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References

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