Enantioselective construction of dispirotriheterocycles featuring a 4-aminopyrazolone motif through a cascade Michael/cyclization process

2020 ◽  
Vol 56 (73) ◽  
pp. 10690-10693 ◽  
Author(s):  
Shiqiang Wei ◽  
Xiaoze Bao ◽  
Wenyao Wang ◽  
Shah Nawaz ◽  
Qimin Dai ◽  
...  
Keyword(s):  
Michael Addition ◽  
Cyclization Reaction ◽  
Cyclization Process ◽  
Stereogenic Centers

A highly asymmetric approach to multicyclic dispiro [pyrazolone-pyrrolidinethione-oxindole] core structures bearing three contiguous stereogenic centers through a cascade Michael addition/cyclization reaction of 4-isothiocyanato pyrazolones with 3-ylideneoxindoles was developed.

One-Pot Synthesis of Highly Substituted Allenylidene Derivatives via Palladium- or Nickel-Catalyzed Tandem Michael Addition-Cyclization Reaction

2009 ◽  
Vol 351 (1-2) ◽  
pp. 141-146 ◽  
Author(s):  
Yun Shi ◽  
Jing Huang ◽  
Yan-Fang Yang ◽  
Lu-Yong Wu ◽  
Yan-Ning Niu ◽  
...  
Keyword(s):  
Michael Addition ◽  
Cyclization Reaction ◽  
One Pot ◽  
One Pot Synthesis

Phosphine-Catalyzed Sequential (2+3)/(2+4) Annulation of γ Vinyl Allenoates: Access to the Synthesis of Chromeno[4,3 b]pyrroles

2021 ◽  
Author(s):  
You Huang ◽  
Xiaohu Li
Keyword(s):  
Cyclization Reaction ◽  
Pyrrole Derivatives ◽  
Stereogenic Centers

A phosphine-catalyzed cascade (2+3)/(2+4) cyclization reaction of γ-vinyl allenoates with aldimine ester has been developed to provide a series of chromeno[4,3-b]pyrrole derivatives, which contain three contiguous stereogenic centers. The method...

Stereocontrolled construction of six vicinal stereogenic centers on a hexahydroxanthone framework through a formal [2+1+3] annulation

2019 ◽  
Vol 55 (93) ◽  
pp. 14003-14006 ◽  
Author(s):  
Shun-Qin Chang ◽  
Xiong Zou ◽  
Yi Gong ◽  
Xue-Wen He ◽  
Xiong-Li Liu ◽  
...  
Keyword(s):  
Michael Addition ◽  
One Pot ◽  
Stereogenic Centers

The first example of a bifunctional donor–donor 3C synthon formed in situ from an activated methine with nitromethane through a [2+1] Michael addition, further directing a one-pot organocascade Michael/Henry cycloaddition was developed.

Enantioselective Michael Addition-Cyclization Reaction

Synfacts ◽  
2007 ◽  
Vol 2007 (7) ◽  
pp. 0738-0738
Author(s):  
A. Alexakis ◽  
K. Li
Keyword(s):  
Michael Addition ◽  
Cyclization Reaction

Enantioselektive Katalyse, XVIII Der Einfluß nicht koordinierter Stereozentren auf die enantioselektive Hydrierung/Enantioselective Catalysis, XVIII The Influence of Non-Coordinated Stereocenters on the Enantioselective Hydrogenation

1998 ◽  
Vol 53 (2) ◽  
pp. 211-223 ◽  
Author(s):  
Ulrich Nagel ◽  
Christoph Roller
Keyword(s):  
Michael Addition ◽  
Enantioselective Hydrogenation ◽  
Palladium Complexes ◽  
Enantioselective Catalysis ◽  
Pyrrolidine Ring ◽  
Enantiomerically Pure ◽  
Stereogenic Centers ◽  
Methyl Phenyl ◽  
Phenyl Vinyl

Abstract 3,4-Bis{[2-(methyl-phenyl-oxophosphanyl)-ethyl]phenyl-phosphanyl}pyrrolidines have be­en synthesized by Michael Addition from the corresponding methyl-phenyl-vinyl-phosphane oxides and 3,4-bis(phenylphosphino)pyrrolidines. For purification of the ligands palladium complexes were used and with the enantiomerically pure ligands Rh complexes have been pre­pared. The catalyst has 6 stereogenic centers. In the hydrogenation of Z-α-acetamidocinnamic acid all six stereogenic centers have an influence on the enantioselectivity. The influence is strongest from the C stereocenters of the pyrrolidine ring. Less important are the stereogenic centers on the coordinated P atoms. The influence of the stereocenters on the non-coordinated P = O groups is the least, but it is not negligible. The ee values obtained with the ligands containing P = O groups are much lower than those obtained with ligands which are substituted only with aryl groups. Ketones are hydrogenated with only low ee’s.

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