720-72-9

Upstream product

• 1846-76-0 ethyl coumarin-3-carboxylate 
• 91-68-9 3-diethylaminophenol 
• 41175-50-2 8-hydroxyjulolidine 
• 105-53-3 diethyl malonate 
• 74-88-4 methyl iodide 
• 3943-94-0 (E)-ethyl 2-hydroxycinnamate 
• 1864-94-4 phenyl formate 
• 90-02-8 salicylaldehyde 

Downstream Products

• 2445-82-1 3-methylcoumarine 
• 66898-40-6 3-propyl-2H-chromen-2-one 
• 64261-57-0 rac–3–benzylchroman–2–one 
• 20280-86-8 3-benzyl-2H-chromen-2-one 
• 64261-55-8 3-benzyl-2-oxo-chroman-3-carboxylic acid ethyl ester 

Relevant academic research and scientific papers

Efficient chemoselective reduction of 3-substituted coumarins utilizing ortho-phenylenediamine and benzaldehyde

2-Phenylbenzimidazoline, generated in situ from ortho-phenylenediamine and benzaldehyde, is an effective reagent to achieve the chemoselective reduction of the styrenic double bond in 3-substituted coumarins, which takes place in high yield.

Substituted coumarins as ambident nucleophiles in one-pot hydrogenation/alkylation reaction

The regioselectivity of a one-pot hydrogenation/alkylation reaction of coumarins 1a and 1b with series of alkyl halides has been elucidated as a complementary work to reaction of acylation with the same coumarins. Reaction conditions have provided formation of only C-alkylation products with good to high yield. The results from the experiments are of significant importance to predict reactivity of 3-substituted coumarins in different reaction conditions.

METHODS FOR ENANTIOSELECTIVE ALLYLIC ALKYLATION OF ESTERS, LACTONES, AND LACTAMS WITH UNACTIVATED ALLYLIC ALCOHOLS

The present disclosure provides methods for enantioselective synthesis of cyclic and acyclic α-quaternary carboxylic acid derivatives via nickel-catalyzed allylic alkylation.

Construction of 3,4-Dihydrocoumarin Derivatives with Adjacent Quaternary and Tertiary Stereocenters: Organocatalytic Asymmetric Michael Addition of 2-Oxochroman-3-carboxylate Esters to trans-β-Nitroolefins

An asymmetric Michael addition of 2-oxochroman-3-carboxylate esters to trans-β-nitroolefins is described. This strategy can give direct access to dihydrocoumarin derivatives bearing adjacent quaternary and tertiary stereocenters with up to >99% yield, >20:1 dr, and >99% ee. The adduct was further transformed to a spiro-dihydrocoumarin compound in three steps with good yield. (Figure presented.).

Synthesis of 3-arylated 3,4-dihydrocoumarins: Combining continuous flow hydrogenation with laccase-catalysed oxidation

A convenient arylation of diverse 3,4-dihydrocoumarins with a number of catechols is described leading to a new class of compounds. As key step, a laccase-catalysed oxidation/Michael addition sequence is applied using commercially available laccase from Agaricus bisporus. 3,4-Dihydrocoumarins were obtained in a rapid and facile two-step sequence starting from salicylaldehydes: The corresponding coumarins were synthesised through a Knoevenagel condensation in up to 83% yield followed by a quantitative reduction performed in a flow system. Combining the reductive flow reaction with the laccase-catalysed arylation also led to successful consecutive one-pot approaches. Overall, the enzyme-catalysed arylations were carried out with yields ranging from 63 to 94%.

A palladium-catalyzed regioselective hydroesterification of alkenylphenols to lactones with phenyl formate as CO source

An effective Pd(OAc)2-PPh3 catalyzed hydroesterification of alkenylphenols with phenyl formate as CO surrogate is described. A variety of lactones are obtained in generally high yields with high regioselectivities. In one case, 76% ee is obtained with a chiral ligand.

Selective reduction of the endocyclic double bond of 3-substituted coumarins by hantzsch 1,4-dihydropyridine

Hantzsch 1,4-dihydropyridine is a valuable reagent to effect the chemoselective reduction of the 3,4-double bond of 3-substituted coumarins. Georg Thieme Verlag Stuttgart.

DIFLUOROSUBSTITUTED HETEROCYCLIC COMPOUNDS AND THE USE THEREOF IN THE FORM OF COMPONENTS IN LIQUID CRYSTALLINE MEDIA

The invention relates to compounds of formula (I), wherein a, b, c, d, e, R1, R2, A1, A2, A3, A4, Y1, Y2, Y3, Z1, Z2, Z3, Z4 and---- are such as defined in claim 1, to a method for the production thereof, intermediates for the production and the use thereof in the form of components in liquid crystalline media and to electrooptic display elements containing said liquid crystalline media.

Reductions via Boranes: A New, Convenient Method for the Preparation of 3-Substituted Esters and Thioesters of 3,4-Dihydrocoumarin

Reduction of various O-ethyl coumarin-3-carboxylates and O-ethyl coumarin-3-thioncarboxylates with diborane, borane dimethyl sulfide, 9-borabicyclononane, and bisethane-diborane lead to the corresponding 3,4-dihydro derivatives with good yields.