One-pot two step synthesis of 5-cyano-dihydropyrimidinones using polyphosphate ester

A new paradigm for designing ring construction strategies for green organic synthesis: implications for the discovery of multicomponent reactions to build molecules containing a single ring

“…Scheme 10 shows the following literature examples of [3 + 2 + 1] cycloadditions following the traditional mapping (red structure shown in Fig. 9): Biginelli [163–165], Shaabani [166], Martins [167], Khodaei [168], Saxena [169], Zhu [170], Zhu [171], Organ [172], Mizar [173], Schmidt [174], Ramalingan [175], Kappe [176], Hulme [177], Tu [178], Matache [179], Zhang [180], Singh [181], Hong [182], Lei [183], Shaabani [184], Tu [185], Han [186], Fang [187], and Zeng [188]. Scheme 11 shows the following literature examples of [3 + 2 + 1] cycloadditions following novel mappings (blue structures shown in Fig.…”

One‐Pot Sequential Synthesis of 2‐Amino‐4, 6‐Diaryl Pyrimidines Involving SO3H‐Functionalized Piperazinium‐Based Dicationic Ionic Liquids as Homogeneous Catalysts

“…A variety of Biginelli scaffolds of 3, 4‐dihydropyrimidin‐2(1 H )‐ones (DHPMs) are prepared by replacement of β‐ketoester component of classical acid catalyzed Biginelli reaction with other types of carbonyl derivatives to react with aldehydes and urea (or thiourea) . Some of these Biginelli‐like reactions used non‐recyclable strong Brönsted or Lewis acid catalysts to get good yields of the products at high temperature in longer reaction time …”

“…Although the number of reports published on the Biginelli (or like) DHPMs scaffolds are increasing tremendously, still there has been lack of efficient methodologies to convert the DHPMs to pyrimidine nucleus using oxidative dehydrogenation‐aromatization method. The inactive nature of DHPMs ring towards variety of oxidants makes dehydrogenation more difficult for which they require high temperature and 36–67 h reaction time to give moderate yields of oxidized products Kappe et al .…”

Benign Methodology and Efficient Catalysis for the One-Pot Multicomponent Synthesis of Dihydropyrimidinones and Thiones: A New Key for Old Lock

“…Previous reported protocols normally required prolonged reaction times and high temperature with moderate yields; so there has been considerable interest in exploring mild, rapid, and high yielding protocol at ambient temperature. Recently, there were some reports which utilized phenylboronic acid [30], triphenylphosphine [31], phosphate ester [32], calcium fluoride [33], and ammonium carbonate in water [34]. But some of these protocols suffered from longer reaction times and requirement of solvents.…”