Enzyme-assisted Cyclization of Chalcones to Flavanones

2020 ◽  
Vol 17 (12) ◽  
pp. 926-931
Author(s):  
Mariana Macías Alonso ◽  
Carlos José Boluda ◽  
Gabriela Díaz Barajas ◽  
Nallely Caldera Sánchez ◽  
Iván Córdova-Guerrero ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Phosphate Buffer ◽  
Room Temperature ◽  
Coupling Constants ◽  
Chemical Methods ◽  
Relative Configuration ◽  
Simple Process ◽  
Mild Conditions ◽  
Reaction Proceeds ◽  
Moderate Yield

Enzyme catalyzed synthesis is an eco-friendly technique in organic synthesis, having several benefits over conventional methods. In the present work, we describe a simple process of laccase and chloroperoxidase assisted cyclization of chalcones, leading to the formation of flavanones. The reaction proceeds in a mixture of phosphate buffer and ethanol, under oxygen atmosphere at room temperature, yielding the corresponding flavanone in good to moderate yield. The relative configuration of the products at C2 is tentatively assigned as S*-flavanone based on the coupling constants with the methylenic protons H3α,β. In comparison to the chemical methods, we describe a process which can be achieved efficiently under mild conditions using oxygen as oxidant.

Bromotrifluoromethane: A Useful Reagent for Hydrotrifluoromethylation of Alkenes and Alkynes

Synlett ◽  
2018 ◽  
Vol 29 (08) ◽  
pp. 1028-1032 ◽  
Author(s):  
Xing Zheng ◽  
Xingang Zhang ◽  
Yu-Yan Ren
Keyword(s):  
Visible Light ◽  
Organic Synthesis ◽  
Functional Group ◽  
Mild Conditions ◽  
Industrial Material ◽  
Reaction Proceeds

Bromotrifluoromethane (CF3Br) is a simple, inexpensive and abundant industrial material employed as a trifluoromethylating reagent. However, only limited strategies using CF3Br as a fluorine source are reported. Herein, we describe a visible-light-induced hydrotrifluoromethylation of alkenes and alkynes with CF3Br. The reaction proceeds under mild conditions with good functional group tolerance, providing a new route for the application of BrCF3 in organic synthesis.

Gem-diallylation of Acyl Azides with Allylsamarium Bromide Under Mild Conditions

2003 ◽  
Vol 2003 (7) ◽  
pp. 438-439 ◽  
Author(s):  
Jian Li ◽  
Yongjun Liu ◽  
Yongmin Zhang
Keyword(s):  
Room Temperature ◽  
Mild Conditions ◽  
Reaction Proceeds ◽  
Acyl Azides

Allylsamarium bromide reacts with acyl azides to give the corresponding gem-diallylation products, 4-alkyl-1,6-heptadienes-4-ols (3), in good to excellent yields. This novel reaction proceeds readily within a few minutes at room temperature.

Diastereoselective One-Pot Tandem Synthesis of Chromenopyridodiazepinones through 1,4- and 1,6-Aza-Conjugate Additions/Heterocyclizations

Synlett ◽  
2018 ◽  
Vol 29 (07) ◽  
pp. 885-889 ◽  
Author(s):  
Oualid Talhi ◽  
Artur Silva ◽  
Abdelghani Bouchama ◽  
Ridha Hassaine ◽  
Nadia Taibi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Amino Group ◽  
Conjugate Additions ◽  
One Pot ◽  
X Ray ◽  
X Ray Crystallography ◽  
Mild Conditions ◽  
Reaction Proceeds ◽  
Tandem Process ◽  
Tandem Synthesis

We report an efficient one-pot synthesis of a novel series of chromenopyridodiazepinone polyheterocycles by a catalyst-free nucleo­philic addition of ethane-1,2-diamine to (E,E)-3-[3-(2-hydroxyphenyl)-3-oxoprop-1-en-1-yl]-2-styrylchromones at room temperature under mild conditions. The reaction proceeds by a tandem process involving 1,4- and 1,6-aza-conjugate additions of one amino group of ethane-1,2-diamine to the α,β-unsaturated (3-oxoprop-1-en-1-yl) and the α,β,γ,δ-diunsaturated (2-styrylchromone) carbonyl system of the precursor, followed by imine condensation of the remaining amino group to generate the chromenopyridodiazepinone polyheterocycle. All compounds were characterized by means of one- and two-dimensional NMR spectroscopy and single-crystal X-ray crystallography.

Novel cyclization and reductive coupling of bicyclic olefins with alkyl propiolates catalyzed by nickel complexes

2002 ◽  
Vol 74 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Dinesh Kumar Rayabarapu ◽  
Chien-Hong Cheng
Keyword(s):  
Nickel Complex ◽  
Room Temperature ◽  
Nickel Complexes ◽  
Coupling Reaction ◽  
Coupling Reactions ◽  
Reductive Coupling ◽  
Mild Conditions ◽  
Reaction Proceeds ◽  
High Yields ◽  
Alkyl Propiolates

In this article, new metal-mediated cyclization and reductive coupling reactions of bicyclic olefins with alkynes are described. Oxabicyclic alkenes undergo cyclization with alkyl propiolates at 80 C catalyzed by nickel complexes to give benzocoumarin derivatives in high yields. The reaction of bicyclic alkenes (oxa- and azacyclic alkenes) with alkyl propiolates at room temperature in the presence of the same nickel complex gave 1,2-dihydro-napthelene derivatives in good-to-excellent yields. This reductive coupling reaction proceeds under very mild conditions in complete regio- and stereoselective fashion. A mechanism to account for the coumarin formation and the reductive coupling is proposed.

Biomass-derived Cu/porous carbon for the electrocatalytic synthesis of cyclic carbonates from CO2 and diols under mild conditions

2020 ◽  
Vol 44 (27) ◽  
pp. 11817-11823
Author(s):  
Jing-Jie Zhang ◽  
Shi-Ming Li ◽  
Yi Shi ◽  
Qiao-Li Hu ◽  
Huan Wang ◽  
...  
Keyword(s):  
Cathode Material ◽  
Porous Carbon ◽  
Room Temperature ◽  
Normal Pressure ◽  
Cyclic Carbonates ◽  
Mild Conditions ◽  
Moderate Yield

A biomass-derived Cu/porous carbon (Cu/PC) cathode material was prepared and used for the electrocatalytic synthesis of cyclic carbonates from diols and CO2 with moderate yield at room temperature and normal pressure.

A new copper species based on an azo-compound utilized as a homogeneous catalyst for water oxidation

2015 ◽  
Vol 44 (1) ◽  
pp. 351-358 ◽  
Author(s):  
Wei-Bin Yu ◽  
Qing-Ya He ◽  
Xiu-Fang Ma ◽  
Hua-Tian Shi ◽  
Xianwen Wei
Keyword(s):  
Copper Complex ◽  
Water Oxidation ◽  
Phosphate Buffer ◽  
High Stability ◽  
Room Temperature ◽  
Homogeneous Catalyst ◽  
Copper Species ◽  
Azo Compound ◽  
Mild Conditions

An azo-conjugated Copper complex efficiently catalyzes water oxidation in a phosphate buffer at pH 11 at room temperature and exhibits high stability and activity toward water oxidation under mild conditions with a TOF of 4.0 kPa h−1.

Fine structural morphology of immunocytes of some molluscs and insects

1990 ◽  
Vol 48 (3) ◽  
pp. 386-387
Author(s):  
S.G. Pal ◽  
G. Baur ◽  
B. Ghosh ◽  
S. Palit ◽  
S. Modak ◽  
...  
Keyword(s):  
Blood Cells ◽  
Phosphate Buffer ◽  
Room Temperature ◽  
Structural Information ◽  
Uranyl Acetate ◽  
Meretrix Meretrix ◽  
Lead Citrate ◽  
Bivalve Molluscs ◽  
Structural Morphology ◽  
Ultrathin Sections

In recent years some of the blood cells of several molluscs and insects are characterised as immunocytes. Similar cells from a few invertebrates from India have been looked into under conventional TEM to register the ultrastructural features. This type of study is first of its kind in the subcontinent. Immunocytes from bivalve molluscs Meretrix meretrix, Laroellidens marqinalis and two insect species, apterygote Ctenolepism a longicaudata and pterygote Gesonula punctifrons provide a new set of fine structural information which forms a basis of comparison with those studied earlier.Immunocytes have been collected from the fresh live species of bivalve molluscs and insects obtained locally at Calcutta. These were fixed in icecold 2% glutaraldehyde in 0.1M phosphate buffer (pH 7.2-7.4) for 1-2 hours at 4-5°C. Subseguently pellets were post-osmicated in 1% OsO4 at room temperature for 1-2 hours. Following dehydration these were embedded in Araldite mixture in plastic capsules and polymerization was effected for 2 days at 60°C. Ultrathin sections were cut in a ultrotome and sections were double stained with Uranyl acetate and lead citrate. These were viewed in a TEM.

SuFEx Activation with Ca(NTf2)2: A Unified Strategy to Access Sulfamides, Sulfamates and Sulfonamides from S(VI) Fluorides

2020 ◽  
Author(s):  
Subham Mahapatra ◽  
Cristian P. Woroch ◽  
Todd W. Butler ◽  
Sabrina N. Carneiro ◽  
Sabrina C. Kwan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Medicinal Chemistry ◽  
Mild Conditions ◽  
Broad Array

<p><br></p> <p>A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds. </p>

SuFEx Activation with Ca(NTf2)2: A Unified Strategy to Access Sulfamides, Sulfamates and Sulfonamides from S(VI) Fluorides

2020 ◽  
Author(s):  
Subham Mahapatra ◽  
Cristian P. Woroch ◽  
Todd W. Butler ◽  
Sabrina N. Carneiro ◽  
Sabrina C. Kwan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Medicinal Chemistry ◽  
Mild Conditions ◽  
Broad Array

<p><br></p> <p>A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds. </p>

scholarly journals Practical Synthesis of 2-Iodosobenzoic Acid (IBA) without Contamination by Hazardous 2-Iodoxybenzoic Acid (IBX) under Mild Conditions

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1897
Author(s):  
Hideyasu China ◽  
Nami Kageyama ◽  
Hotaka Yatabe ◽  
Naoko Takenaga ◽  
Toshifumi Dohi
Keyword(s):  
Aqueous Solution ◽  
Room Temperature ◽  
Practical Method ◽  
Hypervalent Iodine ◽  
Mild Conditions ◽  
Sequential Procedures ◽  
Iodine Compounds ◽  
Practical Synthesis ◽  
Iodosobenzoic Acid ◽  
Lower Temperature

We report a convenient and practical method for the preparation of nonexplosive cyclic hypervalent iodine(III) oxidants as efficient organocatalysts and reagents for various reactions using Oxone® in aqueous solution under mild conditions at room temperature. The thus obtained 2-iodosobenzoic acids (IBAs) could be used as precursors of other cyclic organoiodine(III) derivatives by the solvolytic derivatization of the hydroxy group under mild conditions of 80 °C or lower temperature. These sequential procedures are highly reliable to selectively afford cyclic hypervalent iodine compounds in excellent yields without contamination by hazardous pentavalent iodine(III) compound.

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