1422447-26-4Relevant academic research and scientific papers
Regioselective α-Addition of Deconjugated Butenolides: Enantioselective Synthesis of Dihydrocoumarins
Wu, Bo,Yu, Zhaoyuan,Gao, Xiang,Lan, Yu,Zhou, Yong-Gui
, p. 4006 - 4010 (2017)
The enantioselective α-addition of deconjugated butenolides has rarely been exploited, in contrast to the well-studied γ-addition of deconjugated butenolides. In this study, an unprecedented asymmetric α-addition/transesterification of deconjugated butenolides with ortho-quinone methides generated in situ afforded a series of functionalized 3,4-dihydrocoumarins containing two contiguous stereogenic centers with excellent diastereo- and enantioselectivity. DFT calculations suggested that the rarely observed regioselectivity was due to the distortion energy that resulted from the interaction between the nucleophilic dienolate and the electrophilic ortho-quinone methide.
Bifunctional Amine-Squaramide Catalyzed Friedel–Crafts Alkylation Based on ortho-Quinone Methides in Oil-Water Phases: Enantioselective Synthesis of Triarylmethanes
Wang, Yifeng,Zhang, Cheng,Wang, Haojiang,Jiang, Yidong,Du, Xiaohua,Xu, Danqian
, p. 791 - 797 (2017)
An efficient enantioselective Friedel–Crafts alkylation reaction of electron-rich β-naphthol with in situ generated ortho-quinone methides catalyzed by chiral bifunctional amine-squaramide catalysts has been developed. The chiral triarylmethane derivative
Enantioselective Reactions of 2-Sulfonylalkyl Phenols with Allenic Esters: Dynamic Kinetic Resolution and [4+2] Cycloaddition Involving ortho-Quinone Methide Intermediates
Chen, Ping,Wang, Kai,Guo, Wengang,Liu, Xianghui,Liu, Yan,Li, Can
, p. 3689 - 3693 (2017)
We report herein a dynamic kinetic resolution (DKR) involving ortho-quinone methide (o-QM) intermediates. In the presence of Et3N and the cinchonine-derived nucleophilic catalyst D, the DKR of 2-sulfonylalkyl phenols with allenic esters afforded chiral benzylic sulfones in 57–79 % yield with good to excellent enantioselectivity (85–95 % ee). Furthermore, with 2-(tosylmethyl)sesamols or 2-(tosylmethyl)naphthols, from which stable o-QM substrates can be generated, a formal [4+2] cycloaddition delivered 4-aryl- or alkyl-substituted chromans with excellent enantioselectivity (88–97 % ee).
Regio- A nd Enantioselective Friedel-Crafts Benzhydrylation of Indoles in Carbocyclic Ring with ortho-Quinomethanes: Access to Chiral Diarylindolylmethanes
Chu, Ming-Ming,Chen, Xue-Yang,Wang, Yi-Feng,Qi, Suo-Suo,Jiang, Zhen-Hui,Xu, Dan-Qian,Xu, Zhen-Yuan
, p. 9491 - 9502 (2020/09/03)
The functionalization of indoles in the carbocyclic ring has been achieved via organocatalytic enantioselective Friedel-Crafts benzhydrylation of hydroxyindoles with in situ generated ortho-quinomethanes in oil-water biphases, allowing an efficient access to varied diarylindolylmethanes with a wide substrate scope. The high yields, excellent stereoselectivities, mild conditions, low catalyst loading, and easy scalability also demonstrated the interest of this novel methodology.
Organocatalytic stereoselective conjugate addition of 3-substituted oxindoles with in situ generated ortho-quinone methides
Liang, Weihong,Yin, Wenhao,Wang, Tingzhong,Qiu, Fayang G.,Zhao, Junling
supporting information, p. 1742 - 1747 (2018/04/02)
A novel method for the stereoselective conjugate addition of 3-substituted oxindoles to in situ generated o-QMs was described. This process was catalyzed efficiently by a cinchonidine-derived squaramide catalyst in oil-water phase, furnishing the corresponding 3,3-disubsituted oxindole derivatives in moderate to high yields (up to 98%) with high stereoselectivities (up to 95% ee, 15.4:1 dr). The utility of this reaction was also investigated by the gram-scale synthesis and derivatization of one of the products.
Synthesis of chiral pyrazolone and spiropyrazolone derivatives through squaramide-catalyzed reaction of pyrazolin-5-ones with o-quinone methides
Zhou, Ji,Huang, Wen-Jun,Jiang, Guo-Fang
, p. 1158 - 1161 (2018/02/23)
A bifunctional squaramide-catalyzed reaction of pyrazolin-5-ones with o-quinone methides in situ generated from 2-(1-tosylalkyl)phenols has been successfully developed, providing a facile access to chiral pyrazolones with high enantioselectivities. In addition, the chiral spiropyrazolones with adjacent tertiary and quaternary stereogenic centers can also be obtained through cascade chlorination/cyclization of the chiral pyrazolones.
Asymmetric Synthesis of 2,3-Dihydrobenzofurans by a [4+1] Annulation Between Ammonium Ylides and In Situ Generated o-Quinone Methides
Meisinger, Nicole,Roiser, Lukas,Monkowius, Uwe,Himmelsbach, Markus,Robiette, Rapha?l,Waser, Mario
, p. 5137 - 5142 (2017/04/18)
A highly enantio- and diastereoselective [4+1] annulation between in situ generated ammonium ylides and o-quinone methides for the synthesis of a variety of 2,3-dihydrobenzofurans has been developed. The key factors controlling the reactivity and stereoselectivity were systematically investigated by experimental and computational means and the energy profiles obtained provide a deeper insight into the mechanistic details of this reaction.
Bifunctional squaramide-catalyzed synthesis of chiral dihydrocoumarins via ortho-quinone methides generated from 2-(1-tosylalkyl)phenols
Zhou, Ji,Wang, Mao-Lin,Gao, Xiang,Jiang, Guo-Fang,Zhou, Yong-Gui
, p. 3531 - 3534 (2017/03/30)
A bifunctional squaramide-catalyzed reaction of azlactones with o-quinone methides in situ generated from 2-(1-tosylalkyl)-phenols has been successfully developed under basic conditions, providing an efficient and mild access to chiral dihydrocoumarins bearing adjacent tertiary and quaternary stereogenic centers in high yields with excellent diastereo- and enantioselectivities.
Enantioselective synthesis of functionalized 2-amino-4H-chromenes via the o-quinone methides generated from 2-(1-tosylalkyl)phenols
Wu, Bo,Gao, Xiang,Yan, Zhong,Huang, Wen-Xue,Zhou, Yong-Gui
, p. 4334 - 4338 (2015/06/22)
An efficient bifunctional squaramide-catalyzed Michael addition/cyclization reaction of o-quinone methides generated in situ from 2-(1-tosylalkyl)phenols with active methylene compounds bearing a cyano group has been realized to synthesize chiral 2-amino-
A Concise Synthesis of 2-(2-Hydroxyphenyl)acetonitriles via the o-Quinone Methides Generated from 2-(1-Tosylalkyl)phenols
Wu, Bo,Gao, Xiang,Chen, Mu-Wang,Zhou, Yong-Gui
supporting information, p. 981 - 984 (2016/02/18)
A concise synthesis of 2-(2-hydroxyphenyl)acetonitriles has been developed through reaction of trimethylsilyl cyanide and the o-quinone methides in situ generated from 2-(1-tosylalkyl)phenols under basic conditions. In addition, 2-(2-hydroxyphenyl)acetonitriles could be conveniently transformed to benzofuranones.
