Chiral Phosphoric Acid Catalysis: The Terada Model Revisited

2021 ◽  
Vol 86 (19) ◽  
pp. 13631-13635
Author(s):  
Matthew N. Grayson
Author(s):  
Alemayehu Gashaw ◽  
Dereje Kebebew Debeli ◽  
Meseret Chemeda

: The C-H and N-H functionalization of indoles is an interesting area of research that has a useful impact on organic synthesis due to the availability of chiral indole scaffolds in the discovery of drugs, synthetic bioactive compounds, and natural products. The chiral phosphoric acid catalysts (CPAs) have proven to be a powerful and versatile class of enantioselective organocatalysts. Many asymmetric syntheses of organic compounds have been carried out with these catalysts in C–C and C-N bond formation reactions, and great progress has been reported. By 2011, several reviews were published covering some important topics and recent achievements in this field. Therefore, in this review, the most recent advances, research breakthroughs with key examples involving mechanisms of CPA-catalyzed C-H and N-H functionalization of indoles to form central chirality via Friedel Crafts, Michael type, and rearrangement reactions were reviewed and reported.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xingguang Li ◽  
Meng Duan ◽  
Peiyuan Yu ◽  
K. N. Houk ◽  
Jianwei Sun

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.


2017 ◽  
Vol 4 (7) ◽  
pp. 1407-1410 ◽  
Author(s):  
En Xie ◽  
Abdul Rahman ◽  
Xufeng Lin

An enantioselective aza-Friedel–Crafts reaction of indoles with 1-trifluoromethyl-3,4-dihydro-β-carbolines has been developed to afford tetrahydro-β-carbolines with a CF3- and indole-containing quaternary stereocenter by using chiral phosphoric acid catalysis.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiawen Wang ◽  
Sujuan Zheng ◽  
Subramani Rajkumar ◽  
Jinglei Xie ◽  
Na Yu ◽  
...  

Abstract Chiral molecules with multiple stereocenters are widely present in natural products and pharmaceuticals, whose absolute and relative configurations are both critically important for their physiological activities. In spite of the fact that a series of ingenious strategies have been developed for asymmetric diastereodivergent catalysis, most of these methods are limited to the divergent construction of point chirality. Here we report an enantioselective and diastereodivergent synthesis of trisubstituted allenes by asymmetric additions of oxazolones to activated 1,3-enynes enabled by chiral phosphoric acid (CPA) catalysis, where the divergence of the allenic axial stereogenicity is realized by modifications of CPA catalysts. Density functional theory (DFT) calculations are performed to elucidate the origin of diastereodivergence by the stacking- and stagger-form in the transition state (TS) of allene formation step, as well as to disclose a Münchnone-type activation mode of oxazolones under Brønsted acid catalysis.


2016 ◽  
Vol 14 (7) ◽  
pp. 2205-2209 ◽  
Author(s):  
Jin-Sheng Yu ◽  
Wen-Biao Wu ◽  
Feng Zhou

We report here the first catalytic asymmetric thioacetalization of salicylaldehyde and dithiol. Chiral phosphoric acid STRIP C5 is identified as a powerful catalyst for this reaction to afford various chiral dithioacetals in high to excellent yields and enantioselectivities under mild conditions.


2014 ◽  
Vol 5 (9) ◽  
pp. 3515-3523 ◽  
Author(s):  
Kyohei Kanomata ◽  
Yasunori Toda ◽  
Yukihiro Shibata ◽  
Masahiro Yamanaka ◽  
Seiji Tsuzuki ◽  
...  

Guided by computational studies, the involvement of non-classical C–H⋯O hydrogen bonds and π–π stacking interactions were found to be crucial for high stereocontrol in a chiral phosphoric acid-catalyzed reaction.


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