BINAPO

A novel procedure for the synthesis of an indole skeleton 81 was developed by Mori s group (Scheme 13).16e,16f Enantioselective allylic amination of 78 with A-sulfonated < r/ < -bromoaniline 79 followed by Heck cyclization of 80 provided chiral indoline 81. The treatment of a cyclohexenol derivative 78 with 79 in the presence of Pd2(dba)3-GHGl3 and ( )-BINAPO gave compound 80 with 84% ee in 75% yield. Total syntheses of (—)-tubifoline, (—)-dehydrotubifoline, and (—)-strychnine were achieved from compound 80. 

Tokuoka, E. Kotani, S. Matsimaga, H. Ishizuka, T. Hashimoto, S. Nakajima, M. (2005) Asymmetric ring opening of meso-epoxides catalyzed by the chiral phosphine oxide BINAPO., Tetrahedron Asymmetry 16 2391-2392. 

Stereoview of a 1 1 1 complex of (S)-BINAPO, (If )-camphorsulfonic acid, and acetic acid ... 

SCHEME 4. Molecular structures of BINAPO complexes. [X. Zhang, K. Mashima, K. Koyano, N. Sayo, H. Kumobayashi, S. Akutagawa, and H. Takaya, Tetrahedron Lett., 32, 7283 (1991). Reproduced by permission of Pergamon Press.]... 

The chiral ligand BINAP was originally prepared from 2,2 -binaphthol and resolved by complexation with an optically active Pd complex [ 10]. A new method starting from 2-naphthol was developed (Scheme 3.2) [11], In this method optical resolution was achieved at the stage of BINAP dioxide (BINAPO) by using inexpensive optically active acids such as camphorsul-fonic acid and dibenzoyltartaric acid. 

With BINAPO as ligand, the alkylation of dibenzoate 92 with p-ketoester 101 provides the mono-alkylated product 102 in modest ee (Scheme 8E.13) [65], Subsequently, a simultaneous allylation-Heck annulation reaction provided the pentacycle 103, which was further function-... 

Desymmetrization of a seven-membered cyclic meso compound, followed by a metallo-ene reaction, provides ready access to the trans-hydroazulene skeleton (Scheme 8E.15) [69]. By using BINAP in preference to BINAPO ligand, which gave a lower enantioselectivity (70% ee), two alkylation products were obtained in differential enantioselectivities. The high enantiopurity of the major product 106 may be the consequence of a subsequent kinetic resolution because the second ionization, followed by proton loss from enf-106, involved a matched event. 

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