Organocatalytic Asymmetric Cyclopropanation of 3-Acylcoumarins with 3-Halooxindoles: Access to Spirooxindole-cyclopropa[c]coumarin Compounds

Asymmetric cyclopropane synthesis currently requires bespoke strategies, methods, substrates and reagents, even when targeting similar compounds. This limits the speed and chemical space available for discovery campaigns. Here we introduce a practical and versatile diazocompound, and we demonstrate its performance in the first unified asymmetric synthesis of functionalized cyclopropanes. We found that the redox-active leaving group in this reagent enhances the reactivity and selectivity of geminal carbene transfer. This effect enabled the asymmetric cyclopropanation of a wide range of olefins including unactivated aliphatic alkenes, enabling the 3-step total synthesis of (–)-dictyopterene A. This unified synthetic approach delivers high enantioselectivities that are independent of the stereoelectronic properties of the functional groups transferred. Our results demonstrate that orthogonally-differentiated diazocompounds are viable and advantageous equivalents of single-carbon chirons<i>.</i>

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Pharmacologically potentials of different substituted coumarin derivatives

10.31221/osf.io/w6hdg ◽

2019 ◽

Cited By ~ 1

Author(s):

Chem Int

Keyword(s):

Benzene Ring ◽

Bioactive Compounds ◽

Biological Activities ◽

Pharmacological Properties ◽

Coumarin Derivatives ◽

Wide Range ◽

Anti Oxidant ◽

Anti Inflammatory ◽

Coumarin Compounds

Coumarin and its derivatives are widely spread in nature. Coumarin goes to agroup as benzopyrones, which consists of a benzene ring connected to a pyronemoiety. Coumarins displayed a broad range of pharmacologically useful profile.Coumarins are considered as a promising group of bioactive compounds thatexhibited a wide range of biological activities like anti-microbial, anti-viral,antiparasitic, anti-helmintic, analgesic, anti-inflammatory, anti-diabetic, anticancer,anti-oxidant, anti-proliferative, anti-convulsant, and antihypertensiveactivities etc. The coumarin compounds have immense interest due to theirdiverse pharmacological properties. In particular, these biological activities makecoumarin compounds more attractive and testing as novel therapeuticcompounds.

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Design and Characterization of Novel Dirhodium Coordination Polymers - The Impact of Ligand Size on Selectivity in Asymmetric Cyclopropanation

Catalysis Science & Technology ◽

10.1039/d1cy00109d ◽

2021 ◽

Author(s):

Zhenzhong Li ◽

Lorenz Roesler ◽

Till Wissel ◽

Hergen Breitzke ◽

Kathrin Hofmann ◽

...

Keyword(s):

Coordination Polymers ◽

Ligand Exchange ◽

Dicarboxylic Acids ◽

Sem Images ◽

Asymmetric Cyclopropanation ◽

The Impact

Three chiral dirhodium coordination polymers Rh2-Ln (n=1-3) have been synthesized via ligand exchange between dirhodium trifluoroacetate Rh2(TFA)4 and differently sized chiral dicarboxylic acids derived from L-tert-leucine. SEM images indicate that...

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