Synthesis of 2,2′-bipyrrole-5-carboxaldehydes and their application in the synthesis of B-ring functionalized prodiginines and tambjamines
作者:Papireddy Kancharla、Kevin A. Reynolds
DOI:10.1016/j.tet.2013.07.067
日期:2013.9
Facile, versatile, and cost-effective synthetic routes for the preparation of a range of new 3-alkyl-, 4-alkyl-, 3,4-dialkyl-, and 3-halo-4-alkyl-2,2′-bipyrrole-5-carboxaldehydes have been developed. These 2,2′-bipyrrole-5-carboxaldehydes offer interesting potential as building blocks for making bioactive natural and unnatural products, as demonstrated by the synthesis of B-ring functionalized prodiginines
A general synthesis of 5-unsubstitutedbenzylpyrrole-2-carboxylates was developed based on the reaction of β-nitroacetates with benzylisocyanoacetate. The advantage of this route over other pyrrole syntheses was the regiochemical control of the substitution pattern on the pyrrole ring.
Metalation and Methyl Group Migration in 21-, 22-, and 23-Methylcarbaporphyrins: Synthesis and Characterization of Palladium(II), Rhodium(I), and Rhodium(III) Derivatives
作者:Alissa N. Latham、Gregory M. Ferrence、Timothy D. Lash
DOI:10.1021/acs.organomet.8b00863
日期:2019.1.28
palladium(II) acetate in refluxing acetonitrile for short time periods gave a 23-methyl palladium(II) complex but prolonged reaction times afforded a rearranged 21-methyl product. The 23-methyl complex can be isolated but gradually converts into the 21-methyl derivative even in the solid state. 21-Methyl- and 22-methylcarbaporphyrins reacted with [Rh(CO)2Cl]2 to give rhodium(I) complexes. However,
A new methodology for the preparation of 2-cyanopyrroles and synthesis of porphobilinogen
作者:Maciej Adamczyk、Rajarathnam E. Reddy
DOI:10.1016/0040-4020(96)00941-6
日期:1996.11
Condensation of α-acetoxynitro compounds 4a-f with isocyanoacetonitrile (5) using DBU in THF afforded 2-cyano-3,4-substituted pyrroles 6a-f, in good yield. Porphobilinogen (PBG, 12), the key building block for the preparation of tetrapyrrolic natural products, was synthesized from 2-cyano-3,4-substituted pyrrole 6f, in four steps.
作者:Timothy D. Lash、John R. Bellettini、Jolie A. Bastian、Kendall B. Couch
DOI:10.1055/s-1994-25431
日期:——
Benzyl esters of 5-unsubstituted pyrrole-2-carboxylic acids were prepared in excellent yields by the base-catalyzed condensation of benzyl isocyanoacetate with α-acetoxynitro compounds, or nitroalkenes,in refluxing tetrahydrofuran. These pyrrolic products are important intermediates in the synthesis of porphyrins and related compounds.