94770-93-1Relevant articles and documents
A sustainable multicomponent pyrimidine synthesis
Deibl, Nicklas,Ament, Kevin,Kempe, Rhett
, p. 12804 - 12807 (2015)
Since alcohols are accessible from indigestible biomass (lignocellulose), the development of novel preferentially catalytic reactions in which alcohols are converted into important classes of fine chemicals is a central topic of sustainable synthesis. Multicomponent reactions are especially attractive in organic chemistry as they allow the synthesis of large libraries of diversely functionalized products in a short time when run in a combinatorial fashion. Herein, we report a novel, regioselective, iridium-catalyzed multicomponent synthesis of pyrimidines from amidines and up to three (different) alcohols. This reaction proceeds via a sequence of condensation and dehydrogenation steps which give rise to selective C-C and C-N bond formations. While the condensation steps deoxygenate the alcohol components, the dehydrogenations lead to aromatization. Two equiv of hydrogen and water are liberated in the course of the reactions. PN5P-Ir-pincer complexes, recently developed in our laboratory, catalyze this sustainable multicomponent process most efficiently. A total of 38 different pyrimidines were synthesized in isolated yields of up to 93%. Strong points of the new protocol are its regioselectivity and thus the immediate access to pyrimidines that are highly and unsymmetrically decorated with alkyl or aryl substituents. The combination of this novel protocol with established methods for converting alcohols to nitriles now allows to selectively assemble pyrimidines from four alcohol building blocks and 2 equiv of ammonia.
Cooperative ruthenium complex catalyzed multicomponent synthesis of pyrimidines
Maji, Milan,Kundu, Sabuj
, p. 17479 - 17487 (2019/12/23)
A new set of 2-(2-benzimidazolyl) pyridine ligand based air and moisture stable ruthenium complexes were synthesized and characterized. The catalytic behaviors of these complexes were evaluated towards the multicomponent synthesis of highly substituted py
Acceptorless Dehydrogenative Synthesis of Pyrimidines from Alcohols and Amidines Catalyzed by Supported Platinum Nanoparticles
Sultana Poly, Sharmin,Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Ting, Kah Wei,Toyao, Takashi,Maeno, Zen,Kanda, Yasuharu,Shimizu, Ken-Ichi
, p. 11330 - 11341 (2019/01/03)
A one-pot, acceptorless dehydrogenative method, using a carbon-supported Pt catalyst (Pt/C) along with KOtBu, has been developed for the synthesis of 2,4,6-trisubstituted pyrimidines from secondary and primary alcohols, and amidines. The reaction takes place efficiently using a wide range of substrate scopes (32 examples with isolated yields up to 92%). The Pt/C catalyst that promotes this process is reusable and has a higher turnover number (TON) than those employed in previously reported methods. The results of mechanistic studies suggest that the process takes place through a pathway that begins with Pt-catalyzed acceptorless dehydrogenation of the alcohol substrate, which is followed by sequential condensation, cyclization, and dehydrogenation. Measurements of the turnover frequency combined with the results of density functional theory calculations on different metal surfaces suggest that the adsorption energy of H on the Pt surface is optimal for the acceptorless dehydrogenation process, which causes the higher catalytic activity of Pt over those of other metals.
One-pot four-component reaction for the generation of pyrazoles and pyrimidines
Stonehouse, Jeffrey P.,Chekmarev, Dmitriy S.,Ivanova, Natalya V.,Lang, Stuart,Pairaudeau, Garry,Smith, Neal,Stocks, Michael J.,Sviridov, Sergey I.,Utkina, Lyubov M.
, p. 100 - 104 (2008/09/21)
The palladium-catalysed four-component coupling of a halide, terminal alkyne, molybdenum hexacarbonyl and either a hydrazine or amidine has been shown to be an efficient method for the construction of highly substituted pyrazoles and pyrimidines, respectively, in a one-pot process. Georg Thieme Verlag Stuttgart.
