Natural and synthetic chromenes, fused chromenes, and versatility of dihydrobenzo[h]chromenes in organic synthesis.

Hybrid materials of the metal–organic framework (MOF), chromium(III) terephthalate (MIL-101), and phosphotungstic acid (PTA) were synthesized in aqueous media in the absence of hydrofluoric acid XRD analysis of the MIL101/PTA composites indicates the presence of ordered PTA assemblies residing in both the large cages and small pores of MIL-101, which suggests the formation of previously undocumented structures The MIL101/PTA structure enables a PTA payload 15–2 times higher than previously achieved The catalytic performance of the MIL101/PTA composites was assessed in the Baeyer condensation of benzaldehyde and 2-naphthol, in the three-component condensation of benzaldehyde, 2-naphthol, and acetamide, and in the epoxidation of caryophyllene by hydrogen peroxide The catalytic efficiency was demonstrated by the high (over 80–90%) conversion of the reactants under microwave-assisted heating In four consecutive reaction cycles, the catalyst recovery was in excess of 75%, whereas the product yields were 

Chromium(III) Terephthalate Metal Organic Framework (MIL-101): HF-Free Synthesis, Structure, Polyoxometalate Composites, and Catalytic Properties

Potassium phthalimide-N-oxyl: a novel, efficient, and simple organocatalyst for the one-pot three-component synthesis of various 2-amino-4H-chromene derivatives in water

This review article summarizes the applications of bismuth(III) compounds in organic synthesis since 2002. Although there are an increasing number of reports on applications of bismuth(III) salts in polymerization reactions, and their importance is acknowledged, they are not included in this review. This review is largely organized by the reaction type although some reactions can clearly be placed in multiple sections. While every effort has been made to include all relevant reports in this field, any omission is inadvertent and we apologize in advance for the same (358 references).

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Applications of bismuth(III) compounds in organic synthesis

Solvent-free synthesis of aryl-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydro-xanthenes using silica sulfuric acid as catalyst

Sulfamic acid: a novel and efficient catalyst for the synthesis of aryl-14H-dibenzo[a.j]xanthenes under conventional heating and microwave irradiation

An efficient approach towards three component coupling of one pot reaction for synthesis of functionalized benzopyrans

Bismuth Subnitrate Catalyzed Efficient Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐Ones: An Improved Protocol for the Biginelli Reaction

/pdf/a-novel-one-pot-synthesis-of-14-aryl-14h-dibenzo-a-j-4p0rj8q148.pdf

A novel one pot synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes catalyzed by SelectfluorTM under solvent free conditions

A convenient procedure is reported for the synthesis of benzo[g]-and benzo[h]chromene derivatives via one-pot three-component condensation of aromatic aldehydes with malononitrile or ethyl cyanoacetate and 1-or 2-naphthol in the presence of 10 mol % of titanium tetrachloride as catalyst. The reactions require no solvent; they are characterized by simple experimental procedure and easy isolation and can be performed on enlarged scale.

Efficient synthesis of benzo[ g ]-and benzo[ h ]chromene derivatives by one-pot three-component condensation of aromatic aldehydes with active methylene compounds and naphthols

B. Sunil Kumar

Papers

Sulfamic acid: a novel and efficient catalyst for the synthesis of aryl-14H-dibenzo[a.j]xanthenes under conventional heating and microwave irradiation

An efficient approach towards three component coupling of one pot reaction for synthesis of functionalized benzopyrans

Bismuth Subnitrate Catalyzed Efficient Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐Ones: An Improved Protocol for the Biginelli Reaction

A novel one pot synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes catalyzed by SelectfluorTM under solvent free conditions

Efficient synthesis of benzo[ g ]-and benzo[ h ]chromene derivatives by one-pot three-component condensation of aromatic aldehydes with active methylene compounds and naphthols