Pyridinyloxazolidines: versatile scaffolds for chiral catalyst construction

2006 ◽  
pp. 4672 ◽  
Author(s):  
Steven A. Cardile ◽  
Michael C. Jennings ◽  
Nathan D. Jones
2020 ◽  
Author(s):  
Dung Do

<p>Chiral molecules with their defined 3-D structures are of paramount importance for the study of chemical biology and drug discovery. Having rich structural diversity and unique stereoisomerism, chiral molecules offer a large chemical space that can be explored for the design of new therapeutic agents.<sup>1</sup> Practically, chiral architectures are usually prepared from organometallic and organocatalytic processes where a transition metal or an organocatalyst is tailor-made for desired reactions. As a result, developing a method that enables rapid assembly of chiral complex molecules under metal- and organocatalyst-free condition represents a daunting challenge. Here we developed a straightforward route to create a chiral 3-D structure from 2-D structures and an amino acid without any chiral catalyst. The center of this research is the design of a <a>special chiral spiroimidazolidinone cyclohexadienone intermediate</a>, a merger of a chiral reactive substrate with multiple nucleophillic/electrophillic sites and a transient organocatalyst. <a>This unique substrate-catalyst (“subcatalyst”) dual role of the intermediate enhances </a><a>the coordinational proximity of the chiral substrate and catalyst</a> in the key Aza-Michael/Michael cascade resulting in a substantial steric discrimination and an excellent overall diastereoselectivity. Whereas the “subcatalyst” (hidden catalyst) is not present in the reaction’s initial components, which renders a chiral catalyst-free process, it is strategically produced to promote sequential self-catalyzed reactions. The success of this methodology will pave the way for many efficient preparations of chiral complex molecules and aid for the quest to create next generation of therapeutic agents.</p>


Synlett ◽  
2018 ◽  
Vol 30 (04) ◽  
pp. 488-492 ◽  
Author(s):  
Jin-Sheng Yu ◽  
Hidetoshi Noda ◽  
Naoya Kumagai ◽  
Masakatsu Shibasaki

An α-CF3 amide underwent direct asymmetric Mannich-type reaction to isatin imines in the presence of a chiral catalyst comprising a soft Lewis acid Cu(I), a chiral bisphosphine ligand, and Barton’s base. The Mannich adduct was converted in one step into a unique tricycle bearing a trifluoromethylated chiral center and an α-tertiary amine moiety.


Science ◽  
2011 ◽  
Vol 331 (6023) ◽  
pp. 1395-1396 ◽  
Author(s):  
T. Ooi
Keyword(s):  

2016 ◽  
Author(s):  
Lukasz Albrecht

The development of methods for the preparation of biologically relevant compounds in an enantiomerically enriched form constitutes one of the most significant tasks in the contemporary organic chemistry. In particular, enantioselective reactions where prochiral substrates are converted into enantiomerically enriched products in the presence of chiral catalyst are of great importance. Recently, asymmetric organocatalysis, where simple organic molecules are used as catalysts of various enantiodifferentiating reactions, has become a highly useful synthetic tool enabling for the efficient asymmetric induction based on diverse activation modes. Herein, we report our studies on organocatalytic, enantioselective strategies for the synthesis of biologically relevant molecules such as: quaternary α-amino acids and their isoelectronic analogs α-aminophosphonates, benzo[1,5]oxazocines, α-methylidene-δ-lactones, α-alkylidene-ketones, furfural derivatives, and benzothiophenes. The devised approaches utilize readily available chiral organocatalysts to control stereo-chemical reaction outcomes. Operational simplicity, efficiency and high enantio- and diastereoselectivities are the main benefits of the developed strategies.


Heterocycles ◽  
2021 ◽  
Vol 103 (1) ◽  
pp. 225
Author(s):  
Shinobu Takizawa ◽  
Hiroaki Sasai ◽  
Mohamed S. H. Salem ◽  
Ankit Kumar ◽  
Makoto Sako ◽  
...  

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