Organocatalytic Asymmetric Synthesis of Biologically Relevant 3,3- Dihydroxyphenyloxindoles via para-Quinone Methides Derived from Isatins

2021 ◽  
Vol 86 (8) ◽  
pp. 5489-5498
Author(s):  
Xiangshuo Qin ◽  
Guofeng Liu ◽  
Jigang Gao ◽  
Heng Zhang ◽  
Dongyang Sun ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Quinone Methides ◽  
Biologically Relevant

Tandem [3 + 2] Cycloaddition/1,4-Addition Reaction of Azomethine Ylides and Aza-o-quinone Methides for Asymmetric Synthesis of Imidazolidines

2017 ◽  
Vol 19 (19) ◽  
pp. 5236-5239 ◽  
Author(s):  
Hao Jia ◽  
Honglei Liu ◽  
Zhenyan Guo ◽  
Jiaxing Huang ◽  
Hongchao Guo
Keyword(s):  
Asymmetric Synthesis ◽  
Addition Reaction ◽  
Azomethine Ylides ◽  
Quinone Methides

scholarly journals Asymmetric Synthesis of 2,3-Dihydrobenzofurans by a [4+1] Annulation Between Ammonium Ylides and In Situ Generated o -Quinone Methides

2017 ◽  
Vol 23 (21) ◽  
pp. 5137-5142 ◽  
Author(s):  
Nicole Meisinger ◽  
Lukas Roiser ◽  
Uwe Monkowius ◽  
Markus Himmelsbach ◽  
Raphaël Robiette ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Quinone Methides

Organocatalytic Enantioselective Cycloaddition of o ‐Quinone Methides with Oxazolones: Asymmetric Synthesis of Dihydrocoumarins

2020 ◽  
Vol 5 (42) ◽  
pp. 13259-13262
Author(s):  
Kyeong Seop Kim ◽  
Jihoon Jang ◽  
Dae Young Kim
Keyword(s):  
Asymmetric Synthesis ◽  
Quinone Methides

Asymmetric synthesis of spiro-structural 2,3-dihydrobenzofurans via the bifunctional phosphonium salt-promoted [4 + 1] cyclization of ortho-quinone methides with α-bromoketones

2019 ◽  
Vol 6 (22) ◽  
pp. 3799-3803 ◽  
Author(s):  
Song Zhang ◽  
Xiaojun Yu ◽  
Jianke Pan ◽  
Chunhui Jiang ◽  
Hongsu Zhang ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Phosphonium Salt ◽  
Quinone Methides

A practical and scalable method for highly stereoselective construction of spiro-2,3-dihydrobenzofurans via cyclization of ortho-quinone methides and α-bromoketones by bifunctional phosphonium salt catalysis was developed.

Challenging metal-based transformations. From single-bond activation to catalysis and metallaquinonoids

2003 ◽  
Vol 75 (4) ◽  
pp. 445-460 ◽  
Author(s):  
D. Milstein
Keyword(s):  
Bond Activation ◽  
Single Step ◽  
Catalytic Reactions ◽  
Single Bond ◽  
Quinone Methides ◽  
Pd Catalysts ◽  
Biologically Relevant ◽  
Aryl Chlorides ◽  
Metal Insertion ◽  
Aluminum Alkyls

Catalytic reactions resulting from our C–X (X = H, C, O, N, halide) bond activation studies are described. Aryl chlorides can react with aluminum alkyls in preference to bromides. Using PCP-type Pd catalysts, Heck reaction with aryl iodides and bromides can proceed without involvement of Pd(0). Ru-catalyzed oxidative coupling of arenes with alkenes using O2 was accomplished. Using specifically designed systems, the scope and mechanisms of C–C activation in solution was studied and compared to C–H activation. C–C activation by Rh(I), Ir(I), Ni(II),Pt(II), Ru(II), and Os(II) was observed. Metal insertion into a strong C–C bond can be kinetically and thermodynamically more favorable than the competing C–H activation. Selective, single-step oxidative addition of a strong C–C bond to a metal was observed and kinetically evaluated. Catalytic C–C hydrogenolysis was demonstrated. A combination of C–C activation and C–R formation (R = aryl, silyl) resulted in unusual methylene transfer chemistry. Selective activation of aryl–O and Me–O bonds was observed. New types of interactions between metals and arenes and unusual quinonoid complexes, including quinone methides, xylylenes, methylene arenium, and a metallaquinone, were discovered. C–H and C–C agostic complexes of cationic metals, proposed as intermediates in bond activation, were isolated. Stabilization and controlled release of biologically relevant, extremely unstable, simple quinone methides, was accomplished.

An Organocatalytic Asymmetric Synthesis of Chiral β,β-Diaryl-α-amino Acids via Addition of Azlactones to In Situ Generated para -Quinone Methides

2018 ◽  
Vol 13 (17) ◽  
pp. 2440-2444 ◽  
Author(s):  
Jiyao Yan ◽  
Min Chen ◽  
Herman H-Y. Sung ◽  
Ian D. Williams ◽  
Jianwei Sun
Keyword(s):  
Amino Acids ◽  
Asymmetric Synthesis ◽  
Quinone Methides
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