Tunable Carbon−Carbon and Carbon−Sulfur Cross-Coupling of Boronic Acids with 3,4-Dihydropyrimidine-2-thiones

Abstract

Direct microwave-assisted Pd(0)-catalyzed/Cu(I)-mediated carbon-carbon cross-coupling of 3,4-dihydropyrimidine-2-thiones and boronic acids under Liebeskind-Srogl conditions leads to 2-aryl-1,4-dihydropyrimidines in moderate to high yield. In contrast, Cu(II)-mediated reaction of the same substrates leads to carbon-sulfur cross-coupling. [reaction: see text]

Controlled Microwave Heating in Modern Organic Synthesis

“…Several research groups have reported other high-speed microwave-assisted transition-metal-catalyzed transforma-tions, such as Suzuki, [279] Heck, [280] Sonogashira, [281] Negishi, [282] and Liebeskind-Srogl reactions, [283] BuchwaldHartwig aminations, [284] and related reactions. [285] Bahn and Adolfsson have demonstrated that functionalized 2,5-dihydropyrroles can be obtained by microwavemediated ruthenium-catalyzed ring-closing metathesis (RCM).…”

Recent Developments in Microwave‐Assisted, Transition‐Metal‐Catalysed C–C and C–N Bond‐Forming Reactions

“…An interesting example is the protocol described by Lengar and Kappe; [98] the authors demonstrated that microwave irradiation can tremendously speed up the sluggish thioether-boronic acid Liebeskind-Srogl-type couplings. Moreover an unprecedented novel carbon-carbon cross-coupling reaction was discovered involving thioamides and boronic acids.…”

“…[100] Interestingly, it was demonstrated that although the catalytic Pd 0 /Cu I system resulted solely in carbon-carbon bond formation, the use of stoichiometric amounts of Cu II under an air atmosphere resulted in carbon-sulfur bond formation (Scheme 76). [98,99] It has been shown that both types of thioamide cross-couplings are orthogonal to the traditional base-catalysed Suzuki-Miyaura cross-coupling of aryl halides with boronic acids. Scheme 76.…”

Synthesis and antiviral activity of new substituted pyrimidine glycosides

“…They have been recognized as important heterocyclic compounds due to their diverse biological activities such as Tie-2 kinase inhibitors [2], HIV-1 inhibitor [3], antimalarial [4] secretive adenosine A1 receptor antagonist [5], anticancer [6,7], analgesic [8], and cardiovascular [9] activities. Furthermore, it has been found that 3,4-dihydropyrimidin-2(1H)-ones (DHPMs) have interesting multifaceted pharmacological profile as hepatitis B virus (HBV) replication inhibitors [10][11][12]. Moreover, the pyrimidine ring in an organic molecule also shows prominent activity as antagonist of both a1-adrenergic and serotonin-S2 receptors [13].…”