scholarly journals Correction to “Polyfunctional Imidazolium Aryloxide Betaine/Lewis Acid Catalysts as Tools for the Asymmetric Synthesis of Disfavored Diastereomers”

2019 ◽  
Vol 141 (42) ◽  
pp. 17022-17022
Author(s):  
Felix Willig ◽  
Johannes Lang ◽  
Andreas C. Hans ◽  
Mark R. Ringenberg ◽  
Daniel Pfeffer ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Lewis Acid ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts

Polyfunctional Imidazolium Aryloxide Betaine/Lewis Acid Catalysts as Tools for the Asymmetric Synthesis of Disfavored Diastereomers

2019 ◽  
Vol 141 (30) ◽  
pp. 12029-12043 ◽  
Author(s):  
Felix Willig ◽  
Johannes Lang ◽  
Andreas C. Hans ◽  
Mark R. Ringenberg ◽  
Daniel Pfeffer ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Lewis Acid ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts

Bidentate Lewis acid catalysts in asymmetric synthesis

2002 ◽  
Vol 74 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Keiji Maruoka
Keyword(s):  
Asymmetric Synthesis ◽  
Organic Synthesis ◽  
Lewis Acid ◽  
Lewis Acids ◽  
Asymmetric Induction ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
High Chemical ◽  
Bidentate Lewis Acids

The chemistry of bidentate Lewis acids belongs to an unexplored field of science, and so far has been only poorly studied. This paper illustrates the design of several bidentate Al and Ti Lewis acids, and their successful application to selective organic synthesis, particularly to asymmetric synthesis. For example, a new, chiral bidentate Ti(IV) complex is successfully designed by adding commercially available Ti(OPri)4 and (S)-binaphthol sequentially to 2,2'-bis(tritylamino)-4,4'-dichlorobenzophenone in CH2Cl2, and can be utilized for simultaneous coordination to aldehyde carbonyls, thereby allowing the precise enantioface discrimination of such carbonyls for a new catalytic, practical enantioselective allylation of aldehydes with allyltributyltin. This chiral bidentate Ti(IV) catalyst exhibits uniformly high asymmetric induction as well as high chemical yields for various aldehydes. The present enantioselective allylation is highly chemoselective in the presence of other carbonyl moieties.

Hydrothermal synthesis of Sn-Beta zeolites in F−-free medium

2018 ◽  
Vol 5 (11) ◽  
pp. 2763-2771 ◽  
Author(s):  
Hao Xu ◽  
Xudong Wang ◽  
Peng Ji ◽  
Haihong Wu ◽  
Yejun Guan ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Lewis Acid ◽  
Crystal Size ◽  
Acid Catalysts ◽  
Free Medium ◽  
Lewis Acid Catalysts ◽  
Structure Directing Agent ◽  
Highly Active ◽  
Beta Zeolites

Sn-Beta zeolites, with high Sn content and smaller crystal size, hydrothermally synthesized in F−-free medium using N-cyclohexyl-N,N-dimethylcyclohexanaminium hydroxide as the structure-directing agent with the assistance of Na+ and seed, are highly active as Lewis acid catalysts.

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