1,6-Addition of vinyl p-quinone methides with cyclic sulfamidate imines: access to 4-hydroxyaryl-2,6-diarylpyridines

2020 ◽  
Vol 18 (7) ◽  
pp. 1337-1342 ◽  
Author(s):  
Soumitra Guin ◽  
Santosh K. Gudimella ◽  
Sampak Samanta
Keyword(s):  
Cyclization Reaction ◽  
Quinone Methides ◽  
Open Atmosphere ◽  
High Yields

A base-promoted 1,6-addition–cyclization reaction of vinyl para-quinone methides with cyclic sulfamidate imines in an open atmosphere is reported. This method delivers good to high yields of 2,4,6-trisubstituted pyridines with a valuable phenolic moiety at the C4-position.

Copper-catalyzed 1,6-conjugate addition of para-quinone methides with diborylmethane

2021 ◽  
Author(s):  
Xin Li ◽  
Guoliang Gao ◽  
Songtao He ◽  
Qiuling Song
Keyword(s):  
Catalytic System ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
High Yields

Presented herein is the first 1,6-conjugate addition of diborylmethane, which is promoted by a simple and inexpensive copper catalytic system. This method features high yields, good selectivities and broad functional...

scholarly journals Organocatalytic Asymmetric [2 + 4] Cycloadditions of 3-Vinylindoles with ortho-Quinone Methides

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6751
Author(s):  
Si-Jia Liu ◽  
Man-Su Tu ◽  
Kai-Yue Liu ◽  
Jia-Yi Chen ◽  
Shao-Fei Ni ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Structural Diversity ◽  
Quinone Methides ◽  
Chiral Phosphoric Acid ◽  
Catalytic Asymmetric ◽  
High Yields ◽  
Asymmetric Cycloadditions

Catalytic asymmetric [2 + 4] cycloadditions of 3-vinylindoles with ortho-quinone methides and their precursors were carried out in the presence of chiral phosphoric acid to afford a series of indole-containing chroman derivatives with structural diversity in overall high yields (up to 98%), good diastereoselectivities (up to 93:7 dr) and moderate to excellent enantioselectivities (up to 98% ee). This approach not only enriches the chemistry of catalytic asymmetric cycloadditions involving 3-vinylindoles but is also useful for synthesizing chiral chroman derivatives.

Synthesis of 4-styrylcoumarins via FeCl3-promoted cascade reactions of propargylamines with β-keto esters

2019 ◽  
Vol 17 (16) ◽  
pp. 4005-4013 ◽  
Author(s):  
Li-Qin Yan ◽  
Xiaoting Cai ◽  
Xinwei He ◽  
Hui Wang ◽  
Mengqing Xie ◽  
...  
Keyword(s):  
Cascade Reactions ◽  
Cyclization Reaction ◽  
Quinone Methides ◽  
Keto Esters ◽  
Tandem Cyclization

A versatile and highly regioselective FeCl3-promoted tandem cyclization reaction of in situ generated alkynyl o-quinone methides (o-AQMs) with β-keto esters has been developed.

Non-hydrogen bond catalyst-mediated diastereoselective conjugate additions of 5H-oxazol-4-ones to o-hydroxyphenyl-substituted p-quinone methides

2020 ◽  
Vol 18 (35) ◽  
pp. 6807-6811
Author(s):  
Ziyang Wang ◽  
Anqi Huang ◽  
Fang Fang ◽  
Pengfei Li ◽  
Guokai Liu ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
Conjugate Additions ◽  
High Yields

An efficient DBU-catalyzed conjugate addition of 5H-oxazol-4-ones to o-hydroxyphenyl-substituted p-quinone methides has been developed, affording the valuable diarylmethanes in high yields with excellent diastereoselectivity.

scholarly journals Thiol-to-amine cyclization reaction enables screening of large libraries of macrocyclic compounds and the generation of sub-kilodalton ligands

2019 ◽  
Vol 5 (8) ◽  
pp. eaaw2851 ◽  
Author(s):  
S. S. Kale ◽  
M. Bergeron-Brlek ◽  
Y. Wu ◽  
M. G. Kumar ◽  
M. V. Pham ◽  
...  
Keyword(s):  
Drug Development ◽  
Structure Analysis ◽  
Drug Targets ◽  
Macrocyclic Ligands ◽  
Cyclization Reaction ◽  
Thrombin Inhibitor ◽  
Macrocyclic Compounds ◽  
Cyclization Reactions ◽  
X Ray ◽  
High Yields

Macrocyclic compounds are an attractive modality for drug development, but the limited availability of large, structurally diverse macrocyclic libraries hampers the discovery of leads. Here, we describe the discovery of efficient macrocyclization reactions based on thiol-to-amine ligations using bis-electrophiles, their application to synthesize and screen large libraries of macrocyclic compounds, and the identification of potent small macrocyclic ligands. The thiol-to-amine cyclization reactions showed unexpectedly high yields for a wide substrate range, which obviated product purification and enabled the generation and screening of an 8988 macrocycle library with a comparatively small effort. X-ray structure analysis of an identified thrombin inhibitor (Ki = 42 ± 5 nM) revealed a snug fit with the target, validating the strategy of screening large libraries with a high skeletal diversity. The approach provides a route for screening large sub-kilodalton macrocyclic libraries and may be applied to many challenging drug targets.

Highly Selective One-Pot Synthesis of Polysubstituted Isoflavanes using Styryl Ethers and Electron-Withdrawing ortho-Quinone Methides Generated In Situ

Synlett ◽  
2018 ◽  
Vol 30 (02) ◽  
pp. 189-192 ◽  
Author(s):  
Yujiro Hoshino ◽  
Kiyoshi Honda ◽  
Kenta Tanaka ◽  
Mami Kishimoto ◽  
Naoya Ohtsuka ◽  
...  
Keyword(s):  
Biologically Active ◽  
Quinone Methides ◽  
One Pot ◽  
One Pot Synthesis ◽  
Reaction Proceeds ◽  
Acidic Conditions ◽  
High Yields

A highly selective one-pot synthesis of polysubstituted isoflavanes has been developed. The reaction proceeds through the cycloaddition of methyl styryl ethers, derived from phenylacetaldehyde dimethyl acetals under acidic conditions, with electron-withdrawing ortho-quinone methides generated in situ. When phenylacetaldehyde dimethyl acetals were reacted with salicylaldehydes, the reaction proceeded smoothly to afford the corresponding isoflavanes stereoselectively in high yields and with excellent regioselectivities. The present reaction provides versatile access to functionalized isoflavanes, and constitutes a useful tool for the synthesis of biologically active molecules.

scholarly journals Highly Diastereoselective Synthesis of Tetrahydroquinoline Derivatives via [4 + 2] Annulation of Ortho-Tosylaminophenyl-Substituted Para-Quinone Methides and Cyanoalkenes

2021 ◽  
Vol 9 ◽  
Author(s):  
Taiwei Dong ◽  
Peifeng Wei ◽  
Min Li ◽  
Feng Gao ◽  
Yuan Qin
Keyword(s):  
Biologically Active ◽  
Structural Motif ◽  
Diastereoselective Synthesis ◽  
Atom Economy ◽  
Quinone Methides ◽  
One Pot ◽  
Reaction Performance ◽  
High Yields ◽  
Active Natural

As a privileged structural motif, tetrahydroquinoline skeletons widely exist in biologically active natural products and pharmaceuticals. In this protocol, a highly diastereoselective [4 + 2] annulation of ortho-tosylaminophenyl-substituted p-QMs and cyanoalkenes to construct tetrahydroquinoline derivatives has been successfully achieved. This strategy proceeds efficiently under mild condition, offering straightforward route to a variety of 4-aryl-substituted tetrahydroquinolines with high yields, excellent diastereoselectivities, broad functional group tolerance as well as gram-scale capacity. Moreover, a one-pot reaction sequence utilizing in situ generated p-QMs under the similar condition to build tetrahydroquinoline framework is smoothly conducted with good reaction performance as well as step and atom economy.

Quinones and quinone methides. IX. Oxidation of 2,4-Bis(1,1-dimethylethyl)-6-(4-methoxyphenylmethyl)phenol in alcoholic solvents: Monomeric products and the crystal structure of an unusual dimes, 2-[3,5-Bis(1,1-dimethylethyl)-2-{methoxy-(4-methoxyphenyl)methoxy} phenoxyl-1,5-bis(1,1-dimethylethyl)-3-[methoxy-(4-methoxyphenyl)methyl]benzene

1981 ◽  
Vol 34 (8) ◽  
pp. 1645 ◽  
Author(s):  
L Jurd ◽  
RY Wong
Keyword(s):  
Crystal Structure ◽  
Silver Oxide ◽  
Crystallographic Analysis ◽  
Quinone Methides ◽  
X Ray ◽  
High Yields ◽  
Methyl Benzene

Oxidation of the title benzylphenol (1) with silver oxide in alcoholic media forms benzylic ethers of type (5) in high yields; e.g. oxidation in methanol yields 2,4-bis(1,1-dimethylethyl)-6-[methoxy(4- methoxyphenyl)methyl]phenol(5a) together with an unusual dimer, the structure of which was shown by X-ray crystallographic analysis to be 2-[3,5-bis(1,1-dimethylethyl)-2-{methoxy(4-methoxyphenyl)- methoxy}phenoxy]-1,5-bis(1,1-dimethylethy)-3-[methoxy(4- methoxyphenyl)methyl]benzene (6). The benzylic ethers (5) are convenient intermediates for the syntheses of a variety of compounds related to (1).

Efficient Synthesis of Indole Derivatives Containing the Tetrazole Moeity Utilizing an Ugi-Azide Post-Transformation Strategy

Synlett ◽  
2018 ◽  
Vol 29 (14) ◽  
pp. 1892-1896 ◽  
Author(s):  
Saeed Balalaie ◽  
Ali Nikbakht ◽  
Fatemeh Baghestani ◽  
Frank Rominger
Keyword(s):  
Room Temperature ◽  
Functional Group ◽  
Cyclization Reaction ◽  
Indole Derivatives ◽  
Efficient Synthesis ◽  
Efficient Strategy ◽  
High Yields ◽  
Operational Simplicity ◽  
Transformation Strategy

An efficient strategy has been developed for the synthesis of indole derivatives containing the tetrazole moiety using a AuCl3-catalyzed cyclization reaction. The precursors of the cycloadduct were easily prepared by an Ugi-azide 4-CR in methanol at room temperature. The merit of this protocol lies in its operational simplicity, readily available starting materials, high yields of product, and good functional group tolerance.

Rapid incorporation of difluoroacetate radical into para-quinone methides via radical 1,6-conjugate addition

2021 ◽  
Author(s):  
Xin Li ◽  
Songtao He ◽  
Qiuling Song
Keyword(s):  
Functional Groups ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
High Yields ◽  
Addition Pathway ◽  
Rapid Incorporation

Presented herein is a newly designed strategy which rapidly introduces ethyl difluoroacetate radicals through a dialkylzincs induced radical 1,6-conjugate addition pathway. Besides achieving high yields and excellent functional groups compatibility,...

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