68903-74-2

Upstream product

• 86795-49-5 3-(phenyl-λ³-iodanylidene)chromane-2,4-dione 
• 108-95-2 phenol 
• 1076-38-6 4-hydroxy[1]benzopyran-2-one 
• 3240-34-4 [bis(acetoxy)iodo]benzene 
• 536-74-3 phenylacetylene 
• 932-88-7 1-iodo-2-phenylethyne 
• 932-87-6 1-Bromo-2-phenylacetylene 
• 591-50-4 iodobenzene 

Downstream Products

• 35817-28-8 4-phenoxy-2H-1-benzopyran-2-one 
• 479-12-9 coumestan 

Relevant academic research and scientific papers

One-pot two-step synthesis of 3-iodo-4-aryloxy coumarins and their Pd/C-catalyzed annulation to coumestans

An efficient protocol for the synthesis of various coumestans from the intramolecular annulation of 3-iodo-4-aryloxy coumarins through C-H activation has been developed. When 3-iodo-4-aryloxy coumarins were treated with 10% Pd/C (0.3 mol% Pd) in the presence of sodium acetate, the corresponding coumestans were produced in good to excellent yield. Reusability of the palladium catalyst was investigated in up to three consecutive cycles and it was found that the yield of the reaction was almost unaltered. Sequential iodination and O-arylation of 4-hydroxy coumarins leading to the 3-iodo-4-aryloxy coumarins were also achieved in a one-pot two-step process starting from aryl iodides in high yield. Pivalic acid was revealed to be the most effective additive for the later method to produce 3-iodo-4-phenoxy coumarins. Different functional groups bearing electron-donating as well as withdrawing groups are also tolerant to the reaction conditions.

An efficient route to 4-aryloxycoumarins via one-pot reactions of 4-hydroxycoumarins with hypervalent iodine reagents

Highly efficient reactions of 4-hydroxycoumarin with hypervalent iodine reagents under mild conditions are described, which give rise to 4-aryloxycoumarins in good to excellent yields.

Rhodium(III)-Catalyzed Regioselective Decarboxylative Cyclization for the Synthesis of 4H-Furo[3,2-c]chromen-4-one Derivatives

This contribution describes a regioselective cyclization of hypervalent iodine reagents (HIR) with propiolic acids in the presence of a rhodium catalyst. The mild decarboxylation can tolerate a wide range of groups and generates 4H-furo[3,2-c]chromen-4-one derivatives in good isolated yields. (Figure presented.).

One-Pot Assembly of Fused Heterocycles via Oxidative Palladium-Catalyzed Cyclization of Arylols and Iodoarenes

A one-pot, two-step cyclization reaction of iodoarenes with diversified arylols, including 4-hydroxyquinoline, quinolinone, 4-hydroxypyridine and phenol, has been developed. By using this palladium-catalyzed formal tandem O-arylation, dehydrogenative cross-coupling reaction, a variety of biologically significant fused benzo[4,5]furo heterocycles and dibenzofurans were quickly assembled in high yields with excellent regioselectivity. Notably, the efficient one-pot reaction led to the heterocycles via sequential oxidation, iodination, isomerization and cyclization steps without purification of any reaction intermediates.

Efficient synthesis of β-substituted α-haloenones by rhodium(II)-catalyzed and thermal reactions of iodonium ylides

Rhodium(II)catalyzed and thermal reaction of iodonium ylides are described. Rhodium(II)-catalyzed reactions of iodonium ylides with benzyl halides and acid halides afforded α-chloro-α,β-enones and α-bromo-α,β-enones in good yields, whereas thermal reactions of iodonium ylides in a solvent such as benzene afforded α-iodo-α,β-enones in good yields.

A new and efficient synthesis of coumestan and coumestrol

4-Aryloxy-3-iodocoumarins (4-aryloxy-3-iodo-2H-1-benzopyran-2-one), 4a-c, which are readily available by known procedures starting from 4-hydroxycoumarins 1 a,b and diacetoxyiodobenzenes 2a-c; are cyclized with palladium chloride in triethylamine to yield the coumestanes (6H-benzofuran[3,2-c][1]benzopyran-6-ones) 5a-c.

IODONIUM DERIVATIVES OF β-DICARBONYL COMPOUNDS. XXIII. SYNTHESIS AND PROPERTIES OF IODONIUM DERIVATIVES OF 4-HYDROXYCOUMARIN

The 3-aryliodonio-4-hydroxycoumarin betaines were obtained by the reaction of 4-hydroxycoumarin with (diacetoxyiodo)benzene and 4-methoxy(diacetoxyiodo)benzene in acetone solution.When heated, they form the products from intramolecular arylation, i.e., 3-