Prolines, biaryl substituted

Fluorous Synthesis of Biaryl-Substituted Proline Analogs... 

Proline analogs, biaryl-substituted, fluorous synthesis 112 PS-anthracene, dienophiles 151 PS-carbodiimide 136 Pimine C-2, nucleophilic displacement 119... 

Zhang, W. and Chen, C.H.-T. 2005. Fluorous synthesis of biaryl-substituted prolines by 1,3-dipolar cycloaddition and Suzuki coupling reactions. Tetrahedron Letters, 46 1807-10. 

Scheme 16.68. Two-step sequence for synthesis of biaryl-substituted bicyclic prolines.

Ortho-substituted aromatic amides show atropisomerism as a result of the perpendicular orientation of the aryl and amide moieties. The non-biaryl atropisomers readily undergo racemization through rotation about the aryl-amide bond, indicating the possibility of DKR. For example, (S)-proline mediated addition of acetone to 2-formyl naphthamide gave a 2 1-5.5 1 diastereoisomer mixture with the optical purity of the major anti-isomer ranging from 86% to 91% ee (Scheme 5.24) [72]. 

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