3862-34-8

Upstream product

• 220505-00-0 2'-hydroxy-4'-methoxy-2-O-methoxymethyl-4,5-methylenedioxychalcone 
• 17575-15-4 4-hydroxy-7-methoxycoumarine 
• 2861-28-1 1,3-benzodioxole-5-acetic acid 
• 5470-14-4 (6-bromobenzo[1,3]dioxol-5-yl)acetic acid 
• 717903-52-1 6-(trimethylsilyl)benzo[d][1,3]dioxol-5-yl triflate 
• 533-31-3 Sesamol 
• 38417-65-1 3-(3,4-methylenedioxyphenoxy)-1,2-epoxypropane 
• 3187-53-9 flemichapparin B 
• 1427216-08-7 3-((2-iodo-5-methoxyphenoxy)methyl)-5,6-methylene-dioxybenzofuran 
• 120-80-9 benzene-1,2-diol 
• 3888-94-6 8,9-dihydroxy-3-methoxybenzo[4,5]furo[3,2-c]chromen-6-one 
• 74-97-5 chlorobromomethane 

Relevant academic research and scientific papers

Palladium(II)-Catalyzed C-H Bond Activation/C-C and C-O Bond Formation Reaction Cascade: Direct Synthesis of Coumestans

A palladium catalyzed cascade reaction of 4-hydroxycoumarins and in situ generated arynes has been developed for the direct synthesis of coumestans. This cascade strategy proceeds via C-H bond activation/C-O and C-C bond formations in a single reaction vessel. This methodology affords moderate to good yields of coumestans and is tolerant of a variety of functional groups including halide. The methodology was applied to the synthesis of natural product flemichapparin C.

Copper-catalyzed intramolecular cross dehydrogenative coupling approach to coumestans from 2′-hydroxyl-3-arylcoumarins

A copper-catalyzed intramolecular cross dehydrogenative C-O coupling reaction of 2′-hydroxyl-3-arylcoumarins was developed. This protocol provided a facile and efficient strategy for the construction of natural coumestans and derivatives in moderate to high yields. This transformation exhibited good functional group compatibility and was amenable to substrates with free phenolic hydroxyl groups.

Method for preparing coumarino-heteroaromatic ring compounds and derivatives thereof through intramolecular cross-dehydrogenation coupling

The invention relates to a method for preparing coumarino-heteroaromatic ring compounds and derivatives thereof through intramolecular cross-dehydrogenation coupling. Specifically, compounds as shownin a formula Ia is subjected to intramolecular cross dehydrogenative coupling under the catalysis of palladium so as to prepare coumarin-heteroaromatic compounds as shown in a formula I, wherein groups in the formulas are as defined in the specification. The method is mild in reaction conditions, simple to operate, high in atom economy and applicable to a wide range of substrates, and high-yield preparation of multi-functionally substituted coumarin-heteroaromatic compounds and derivatives thereof is realized.

Syntheses of pterocarpenes and coumestans via regioselective cyclodehydration

A highly efficient synthetic route to pterocarpenes and coumestans is described. BCl3-mediated dehydrative cyclization of 1,3-diaryloxyacetones under mild conditions permitted regioselective ring closure to afford 3-((2-iodoaryloxy)methyl)benzo

Cyclization of 4-Phenoxy-2-coumarins and 2-Pyrones via a Double C-H Activation

Aryl-heteroaryl coupling via double C-H activation is a powerful transformation that avoids the installation of activating groups. A double C-H activation of privileged biological scaffolds, 2-coumarins and 2-pyrones, is reported. Despite the rich chemistry of these molecular frameworks, the yields are very good. Excellent regioselectivity was achieved on the pyrones. This methodology was applied to the synthesis of flemichapparin C in three steps. Isotope effect experiments were carried out, and a mechanism is proposed.

Intramolecular Direct Arylation of 3-Halo-2-pyrones and 2-Coumarins

Direct arylation represents a favorable alternative to traditional cross-coupling and has found widespread use with simple aryls and robust heterocycles. Herein a direct arylation protocol has been optimized and applied to 2-pyrones, which are delicate an

O-heterocycles via laccase-catalyzed domino reactions with O2 as the oxidant

Laccase-catalyzed domino reactions of 4-hydroxy-6-methyl-2H-pyran-2-one or substituted 4-hydroxy-2H-chromen-2-ones with catechols using molecular oxygen as an oxidant afford coumestans and related O-heterocycles with yields ranging from 51% to 99%. Georg Thieme Verlag Stuttgart.

The first direct transformation of 2,2'-dihydroxychalcones into coumestans

Three coumestans, flemichapparin, medicagol and sophoracoumestan B, are synthesised by direct reaction of the analogous 2,2'-dihydroxychalcones with thallium (III) nitrate in methanol.