A Selective and Versatile Synthesis of Substituted Chromones via Addition of Phenols to Dimethyl Acetylenedicarboxylate

1995 ◽  
Vol 48 (3) ◽  
pp. 677 ◽  
Author(s):  
MJ Stoermer ◽  
DP Fairlie
Keyword(s):  
Functional Groups ◽  
Addition Reaction ◽  
Initial Step ◽  
High Yield ◽  
Selective Synthesis ◽  
Dimethyl Acetylenedicarboxylate ◽  
Substituted Phenols ◽  
Valuable Component ◽  
Mild Conditions ◽  
Wide Range

Despite many published syntheses of chromones, none has been reported to be both selective for chromones and tolerant of ring substitution. The addition of substituted phenols to dimethyl acetylenedicarboxylate is now reported as a versatile high yield initial step in a simple three-step synthesis of chromone 2-carboxylic acids. Triethylamine being used to deprotonate the substituted phenol, the addition to dimethyl acetylenedicarboxylate proceeds under mild conditions and tolerates a wide range of functional groups on the phenol. Although not stereoselective, both fumarate and maleate aryloxy products of this addition can then be cyclized, according to a known method, to chromones without contamination by isomeric coumarins. Thus the addition reaction is a valuable component of a versatile and selective synthesis of substituted chromones.

scholarly journals Room-Temperature, Base-Mediated Selective Synthesis of 2-(Arylamino)ethanols and 2-Aryloxyethanols

SynOpen ◽  
2019 ◽  
Vol 03 (04) ◽  
pp. 124-137 ◽  
Author(s):  
Rahul B. Sonawane ◽  
Swapnali R. Sonawane ◽  
Nishant K. Rasal ◽  
Sangeeta V. Jagtap
Keyword(s):  
Functional Groups ◽  
Aromatic Amines ◽  
Room Temperature ◽  
Alkyl Halide ◽  
Selective Synthesis ◽  
Formal Synthesis ◽  
Mild Conditions ◽  
Primary Aromatic Amines

A simple and efficient protocol for base-mediated selective synthesis of 2-(arylamino)ethanols from primary aromatic amines and 2-aryloxyethanols from phenols, promoted by K2CO3 has been achieved under mild conditions. Even in presence of excess alkyl halide, selective mono-N-alkylation has been achieved. Tolerance of a variety of functional groups is demonstrated by 15 examples of selective N-alkylation of aromatic amines and 19 examples of O-alkylation of phenols. The efficacy of the protocol is demonstrated by the formal synthesis of Ticlopidine­®, Vildagliptin®, Quetiapine®, and Gemfibrozil®.

scholarly journals Palladium-Catalyzed Cross-Coupling of Gem-Bromofluoroalkenes with Alkylboronic Acids for the Synthesis of Alkylated Monofluoroalkenes

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5532
Author(s):  
Laëtitia Chausset-Boissarie ◽  
Nicolas Cheval ◽  
Christian Rolando
Keyword(s):  
Organic Synthesis ◽  
Functional Group ◽  
Materials Science ◽  
Cross Coupling ◽  
High Yield ◽  
Efficient Synthesis ◽  
Mild Conditions ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Novel Strategy

Monofluoroalkenes are versatile fluorinated synthons in organic synthesis, medicinal chemistry and materials science. In light of the importance of alkyl-substituted monofluoroalkenes efficient synthesis of these moieties still represents a synthetic challenge. Herein, we described a mild and efficient methodology to obtain monofluoroalkenes through a stereospecific palladium-catalyzed alkylation of gem-bromofluoroalkenes with primary and strained secondary alkylboronic acids under mild conditions. This novel strategy gives access to a wide range of functionalized tri- and tetrasubstituted monofluoroalkenes in high yield, with good functional group tolerance, independently from the gem-bromofluoroalkenes geometry.

A Practical Access to Functionalized Alkyl Sulfinates

Synlett ◽  
2018 ◽  
Vol 29 (12) ◽  
pp. 1622-1626
Author(s):  
M. Haddad ◽  
P. Phansavath ◽  
V. Ratovelomanana-Vidal ◽  
C. Tran ◽  
B. Flamme ◽  
...  
Keyword(s):  
Functional Groups ◽  
Cost Effective ◽  
Good Tolerance ◽  
Mild Conditions ◽  
Cost Effective Method ◽  
Wide Range

We describe herein a three-step synthesis of aliphatic sulfinates. This cost-effective method involves the use of 2-mercaptobenzothiazole under mild conditions and exhibits good yields (up to 78% over three steps). This approach provides an access to a wide range of functionalized sulfinates. A good tolerance with respect to diverse functional groups (alkene, alkyne, ether, acetal) was also noted.

scholarly journals Asymmetric Synthesis of Tetrahydroisoquinoline Derivatives through 1,3-Dipolar Cycloaddition of C,N-Cyclic Azomethine Imines with Allyl Alkyl Ketones

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2969
Author(s):  
Guipeng Feng ◽  
Guoyang Ma ◽  
Wenyan Chen ◽  
Shaohong Xu ◽  
Kaikai Wang ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Functional Groups ◽  
Absolute Configuration ◽  
Dipolar Cycloaddition ◽  
Quantum Electronic ◽  
Mild Conditions ◽  
Spectrum Method ◽  
Wide Range ◽  
Reaction Proceeds ◽  
Azomethine Imines

[3 + 2] A 1,3-Dipolar cycloaddition of C,N-cyclic azomethine imines with allyl alkyl ketones has been achieved. The reaction proceeds under mild conditions and tolerates a wide range of functional groups. An array of tetrahydroisoquinoline derivatives is generally constructed with good diastereoselectivities and enantioselectivities (up to >25:1 dr, >95% ee). Moreover, the absolute configuration of the product was previously determined by using the quantum electronic circular dichroism calculation and ECD spectrum method.

Fe(NO3)3·9H2O-catalyzed aerobic oxidative deoximation of ketoximes and aldoximes under mild conditions

2018 ◽  
Vol 96 (8) ◽  
pp. 810-814 ◽  
Author(s):  
Yongshu Li ◽  
Nizhou Xu ◽  
Guangyao Mei ◽  
Yun Zhao ◽  
Yiyong Zhao ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Functional Groups ◽  
Environmentally Benign ◽  
Synthetic Method ◽  
Simple Process ◽  
Practical Applications ◽  
Mild Conditions ◽  
Excellent Yield ◽  
Wide Range ◽  
Plausible Mechanism

A mild, simple process for the effective aerobic oxidative deoximation of a wide range of ketoximes and aldoximes has been developed that utilizes Fe(NO3)3·9H2O as the single catalyst and molecular oxygen as the green oxidant. The environmentally benign protocol provides moderate to excellent yield and broad functional groups tolerance and is a valuable synthetic method for practical applications. According the relevant verification experiment, a plausible mechanism has been proposed.

scholarly journals 3,3-Difluoroallyl ammonium salts: highly versatile, stable and selective gem-difluoroallylation reagents

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fei Ye ◽  
Yao Ge ◽  
Anke Spannenberg ◽  
Helfried Neumann ◽  
Li-Wen Xu ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Organic Molecules ◽  
Metal Catalysts ◽  
Ammonium Salts ◽  
Direct Reaction ◽  
Selective Synthesis ◽  
Mild Conditions ◽  
Wide Range

AbstractThe selective synthesis of fluorinated organic molecules continues to be of major importance for the development of bioactive compounds (agrochemicals and pharmaceuticals) as well as unique materials. Among the established synthetic toolbox for incorporation of fluorine-containing units, efficient and general reagents for introducing -CF2- groups have been largely neglected. Here, we present the synthesis of 3,3-difluoropropen-1-yl ammonium salts (DFPAs) as stable, and scalable gem-difluoromethylation reagents, which allow for the direct reaction with a wide range of fascinating nucleophiles. DFPAs smoothly react with N-, O-, S-, Se-, and C-nucleophiles under mild conditions without necessity of metal catalysts with exclusive regioselectivity. In this way, the presented reagents also permit the straightforward preparation of many analogues of existing pharmaceuticals.

Visible-Light-Triggered Decarboxylative Alkylation of 8-Acylaminoquinoline with N-Hydroxyphthalimide Ester

Synlett ◽  
2020 ◽  
Vol 31 (07) ◽  
pp. 677-682 ◽  
Author(s):  
Bin Sun ◽  
Deyu Li ◽  
Xiaohui Zhuang ◽  
Rui Zhu ◽  
Aertuke Aisha ◽  
...  
Keyword(s):  
Visible Light ◽  
Functional Groups ◽  
Efficient Approach ◽  
Radical Coupling ◽  
Mild Conditions ◽  
Highly Efficient ◽  
Wide Range ◽  
Reaction Proceeds ◽  
Operational Simplicity

A facile protocol for visible-light-induced decarboxylative radical coupling of NHP esters with 8-aminoquinoline amides is reported, affording a highly efficient approach to synthesize a variety of 2-alkylated or 2,4-dialkylated 8-aminoquinoline derivatives. The reaction proceeds smoothly without adding any ligand, and provides the corresponding products containing a wide range of functional groups in moderate to excellent yields. This reaction uses readily available starting materials, and proceeds under mild conditions and with operational simplicity.

Coupling of N-Nosylhydrazones with Nitrosoarenes: Transition-Metal-Free Approach to (Z)-N-Arylnitrones

Synthesis ◽  
2018 ◽  
Vol 50 (08) ◽  
pp. 1728-1736 ◽  
Author(s):  
Tingting Liu ◽  
Zhaohong Liu ◽  
Zhenhua Liu ◽  
Donghua Hu ◽  
Yeming Wang
Keyword(s):  
Transition Metal ◽  
Functional Groups ◽  
Direct Coupling ◽  
Recrystallization Process ◽  
Metal Free ◽  
Mild Conditions ◽  
Wide Range

An efficient and transition-metal-free protocol for the synthesis of (Z)-N-arylnitrones from the direct coupling of N-nosylhydrazones with nitrosoarenes under mild conditions is described. The protocol is compatible with a wide range of functional groups placed on both the reagents and provided the corresponding nitrones in good to excellent yields by simple recrystallization process. The use of these 1,3-dipoles for the synthesis of substituted indoles is elaborated for 2,3-diphenyl-1H-indole.

Synthesis of 1,3,4-Oxadiazoles by Iodine-mediated Oxidative Cyclization of Methyl Ketones with 4-Phenylsemicarbazide

Synlett ◽  
2021 ◽  
Author(s):  
Shanshan Zhang ◽  
Chuang Liu ◽  
Xiaojun Wu ◽  
Wen Li ◽  
He Li ◽  
...  
Keyword(s):  
Functional Groups ◽  
Oxidative Cyclization ◽  
Methyl Ketones ◽  
One Pot ◽  
Mild Conditions ◽  
Wide Range ◽  
Reaction Proceeds ◽  
Aryl Methyl

An efficient one-pot method to access 5-amino-2-benzoyl-1,3,4-oxadiazoles via I2/DMSO promoted oxidative cyclization of 4-phenylsemicarbazide with (het)aryl methyl ketones under mild conditions was developed. This reaction proceeds smoothly with a wide range of methyl ketones containing different functional groups to give the corresponding products in moderate yields under mild conditions.

Double Ring-Closing Approach for the Synthesis of 2,3,6,7-Substituted Anthracene Derivatives

2020 ◽  
Author(s):  
Birgit Meindl ◽  
Katharina Pfennigbauer ◽  
Berthold Stöger ◽  
Martin Heeney ◽  
Florian Glöcklhofer
Keyword(s):  
Wittig Reaction ◽  
Condensation Reaction ◽  
Synthetic Methods ◽  
Anthracene Derivative ◽  
Double Ring ◽  
Mild Conditions ◽  
Wide Range ◽  
Anthracene Derivatives

Anthracene derivatives have been used for a wide range of applications and many different synthetic methods for their preparation have been developed. However, despite continued synthetic efforts, introducing substituents in some positions has remained difficult. Here we present a method for the synthesis of 2,3,6,7-substituted anthracene derivatives, one of the most challenging anthracene substitution patterns to obtain. The method is exemplified by the preparation of 2,3,6,7-anthracenetetracarbonitrile and employs a newly developed, stable protected 1,2,4,5-benzenetetracarbaldehyde as the precursor. The precursor can be obtained in two scalable synthetic steps from 2,5-dibromoterephthalaldehyde and is converted into the anthracene derivative by a double intermolecular Wittig reaction under very mild conditions followed by a deprotection and intramolecular double ring-closing condensation reaction. Further modification of the precursor is expected to enable the introduction of additional substituents in other positions and may even enable the synthesis of fully substituted anthracene derivatives by the presented approach.<br>

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