scholarly journals Organocatalytic enantioselective conjugate addition of 2-naphthols to ortho-hydroxyphenyl substituted para-quinone methides: access to unsymmetrical triarylmethanes

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24212-24217 ◽  
Author(s):  
Yuyu Cheng ◽  
Zhiqiang Fang ◽  
Yanwen Jia ◽  
Zhongyue Lu ◽  
Wenjun Li ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
Chiral Phosphoric Acid

The enantioselective conjugate addition of 2-naphthols to ortho-hydroxyphenyl substituted para-quinone methides has been achieved with the aid of a chiral phosphoric acid.

Organocatalytic site- and stereoselective 1,6-additions of N-aryl-3-oxobutanamides to propargylic aza-p-quinone methides

2020 ◽  
Vol 7 (21) ◽  
pp. 3446-3451
Author(s):  
Fushuai Li ◽  
Xuling Chen ◽  
Shuai Liang ◽  
Zhenyan Shi ◽  
Pengfei Li ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
Propargylic Alcohols ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed ◽  
Site Selective ◽  
First Time

A chiral phosphoric acid catalyzed site-selective 1,6-conjugate addition of N-aryl-3-oxobutanamides to in situ formed propargylic aza-p-quinone methides from propargylic alcohols has been established for the first time.

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.

scholarly journals Organocatalytic enantioselective dearomatization of thiophenes by 1,10-conjugate addition of indole imine methides

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xingguang Li ◽  
Meng Duan ◽  
Peiyuan Yu ◽  
K. N. Houk ◽  
Jianwei Sun
Keyword(s):  
Hydrogen Bonding ◽  
Phosphoric Acid ◽  
Nucleophilic Addition ◽  
Acid Catalysis ◽  
Conjugate Addition ◽  
Mild Conditions ◽  
Rapid Construction ◽  
Chiral Phosphoric Acid ◽  
Cyclic Molecules ◽  
Selectivity Control

AbstractCatalytic asymmetric dearomatization (CADA) is a powerful tool for the rapid construction of diverse chiral cyclic molecules from cheap and easily available arenes. This work reports an organocatalytic enantioselective dearomatization of substituted thiophenes in the context of a rare remote asymmetric 1,10-conjugate addition. By suitable stabilization of the thiophenyl carbocation with an indole motif in the form of indole imine methide, excellent remote chemo-, regio-, and stereocontrol in the nucleophilic addition can be achieved with chiral phosphoric acid catalysis under mild conditions. This protocol can be successfully extended to the asymmetric dearomatization of other heteroarenes including selenophenes and furans. Control experiments and DFT calculations demonstrate a possible pathway in which hydrogen bonding plays an important role in selectivity control.

Asymmetric organocatalytic synthesis of chiral 3,3-disubstituted oxindolesviaa 1,6-conjugate addition reaction

2018 ◽  
Vol 16 (29) ◽  
pp. 5301-5309 ◽  
Author(s):  
Abdul Rahman ◽  
Qiaoxia Zhou ◽  
Xufeng Lin
Keyword(s):  
Phosphoric Acid ◽  
Addition Reaction ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
Acid Catalyzed

The chiral spirocyclic phosphoric acid-catalyzed enantioselective 1,6-conjugate addition reaction ofpara-quinone methides derived fromN-unprotected isatins with indoles was developed.

Chiral phosphoric acid catalyzed asymmetric addition of naphthols to para-quinone methides

2016 ◽  
Vol 14 (24) ◽  
pp. 5751-5754 ◽  
Author(s):  
Yuk Fai Wong ◽  
Zhaobin Wang ◽  
Jianwei Sun
Keyword(s):  
Phosphoric Acid ◽  
Quinone Methides ◽  
Asymmetric Addition ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed

An asymmetric addition of naphthols to in situ generated para-quinone methides catalyzed by a chiral phosphoric acid is described.

Organocatalytic Stereoselective 1,6-Addition of Thiolacetic Acids to Propargylic Indole Imine Methides: Access to Axially Chiral Sulfur-containing Tetrasubstituted Allenes

2021 ◽  
Author(s):  
Ziyang Wang ◽  
Xiao Lin ◽  
Xuling Chen ◽  
Pengfei Li ◽  
Wenjun Li
Keyword(s):  
Phosphoric Acid ◽  
Conjugate Addition ◽  
Chiral Phosphoric Acid ◽  
Axially Chiral ◽  
Propargylic Alcohol ◽  
Acid Catalyzed ◽  
Sulfur Containing ◽  
Thiolacetic Acid

A chiral phosphoric acid catalyzed enantioselective 1,6-conjugate addition of thiolacetic acid to propargylic indole imine methide in situ formed from α-(3-indolyl) propargylic alcohol has been established, which enables the formation...

Asymmetric Cycloaddition of ortho-Hydroxyphenyl-Substituted para-Quinone Methides and Enamides Catalyzed by Chiral Phosphoric Acid

2019 ◽  
Vol 84 (12) ◽  
pp. 7883-7893 ◽  
Author(s):  
Guo-Hui Yang ◽  
Qun Zhao ◽  
Zhi-Pei Zhang ◽  
Han-Liang Zheng ◽  
Li Chen ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Quinone Methides ◽  
Chiral Phosphoric Acid

Chiral phosphoric acid catalyzed enantioselective annulation of acyclic enecarbamates to in situ-generated ortho-quinone methides

2017 ◽  
Vol 15 (35) ◽  
pp. 7272-7276 ◽  
Author(s):  
Chandan Gharui ◽  
Shreya Singh ◽  
Subhas Chandra Pan
Keyword(s):  
Phosphoric Acid ◽  
Cycloaddition Reaction ◽  
Quinone Methides ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed ◽  
Phosphoric Acids

The first organocatalytic asymmetric [4 + 2]-cycloaddition reaction between acyclic enecarbamates with in situ generated ortho-quinone methides has been developed using chiral phosphoric acids as catalysts.

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