Manganese‐Catalyzed Multicomponent Synthesis of Pyrimidines from Alcohols and Amidines

Abstract

The development of catalytic reactions for synthesizing different compounds from alcohols to save fossil carbon feedstock and reduce CO emissions is of high importance. Replacing rare noble metals with abundantly available 3d metals is equally important. We report a manganese-complex-catalyzed multicomponent synthesis of pyrimidines from amidines and up to three alcohols. Our reaction proceeds through condensation and dehydrogenation steps, permitting selective C-C and C-N bond formations. β-Alkylation reactions are used to multiply alkylate secondary alcohols with two different primary alcohols to synthesize fully substituted pyrimidines in a one-pot process. Our PN P-Mn-pincer complexes efficiently catalyze this multicomponent process. A comparison of our manganese catalysts with related cobalt catalysts indicates that manganese shows a reactivity similar to that of iridium but not cobalt. This analogy could be used to develop further (de)hydrogenation reactions with manganese complexes.

Eco‐Mn Ecocatalysts: Toolbox for Sustainable and Green Lewis Acid Catalysis and Oxidation Reactions

“…Among these elements, manganese is the main topic of numerous publications devoted to tandem oxidation, mainly Mn(III) and Mn(IV) . For instance, manganese has recently attracted wide interest for multicomponent reactions based on pincer‐type manganese complexes …”

Manganese‐Catalyzed Direct Olefination of Methyl‐Substituted Heteroarenes with Primary Alcohols

“…[15] In this regard, manganese,a st he third most abundant transition metal, has appeared as an attractive alternative. [17] Subsequently,m anganese complexes were utilized for catalytic dehydrogenations of methanol to CO 2 and H 2 , [18] dehydrogenative Nformylations of amines, [19] couplings of alcohols to esters, [20] syntheses of imines, [21] quinolines, [22] pyrimidines, [22,23] pyrroles, [24] cyclic imides, [25] amides, [26] and a,bunsaturated nitriles, [27] as well as hydrogenations of polar double bonds. [17] Subsequently,m anganese complexes were utilized for catalytic dehydrogenations of methanol to CO 2 and H 2 , [18] dehydrogenative Nformylations of amines, [19] couplings of alcohols to esters, [20] syntheses of imines, [21] quinolines, [22] pyrimidines, [22,23] pyrroles, [24] cyclic imides, [25] amides, [26] and a,bunsaturated nitriles, [27] as well as hydrogenations of polar double bonds.…”

Manganese‐Catalyzed Sustainable Synthesis of Pyrroles from Alcohols and Amino Alcohols

“…[10] Aside from the conservation of our fossil carbon resources,t he conservation of rare noble metals,w hich are frequently used in key technologies such as catalysis,issimilarly important. [12] Kirchner and co-workers [13] and our group [14] described aM n-complex-catalyzed multicomponent synthesis of pyrimidines from up to three different alcohols and amidines, ar eaction originally developed by our group with Ir catalysts. Milstein and co-workers showed very recently that aC o complex efficiently catalyzes the synthesis of pyrroles from diols and amines, [11] ar eaction originally introduced by the Crabtree group with aR uc atalyst (Scheme 1, top).…”

“…[15] Efficient hydrogenation and dehydrogenation catalysis with Mn has only been reported very recently. [14] Next, PN 5 P-ligand-supported Mn carbonyl complexes were investigated (Table 1, entries 1-6). A Scheme 1.…”