Dihydropyrromethenones by Pd(0)-Mediated Coupling of Iodopyrroles and Acetylenic Amides. Synthesis of the A,B-Ring Segment of Phytochrome
作者:Peter A. Jacobi、Jiasheng Guo、S. Rajeswari、Wanjun Zheng
DOI:10.1021/jo970289b
日期:1997.5.1
Dihydropyrromethenone derivative 32b, which constitutes the A,B-ring segment of phytochrome (6), has been prepared in enantiomerically pure form beginning with acetylenic amide 47b and iodopyrrole 27. The key steps involved the TBAF-catalyzed 5-exo-dig cyclization of the acetylenic pyrrole 48b, followed by thia-Mitsunobu inversion of the resulting alcohol derivative 31b.
Tetrapyrroles. III. Homochiral dihydropyrromethenones from N-Aminopyrroles and acetylenic acids
作者:Peter A. Jacobi、S. Rajeswari
DOI:10.1016/s0040-4039(00)60940-1
日期:1992.10
Dihydropyrromethenone 29, a potential precursor for the synthesis of Phytochrome (8), Phycocyanin (9)and Phycoerythrin (10), has been prepared in homochiral form from pyrrolohydrazide 27 by a sequence involving F- induced 5-exo-dig cyclization to afford enamide 28, followed by photochemical 3,5-sigmatropic rearrangement.