scholarly journals Iron bis(oxazoline) complexes in asymmetric catalysis

2016 ◽  
Vol 6 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Thierry Ollevier
Keyword(s):  
Asymmetric Catalysis ◽  
Lewis Acid ◽  
Iron Complexes ◽  
Oxidation Catalysis ◽  
Asymmetric Reactions ◽  
Environmentally Benign

Asymmetric reactions catalyzed by iron complexes have attracted considerable attention because iron is a ubiquitous, inexpensive, and environmentally benign metal. This overview charts the development and application of chiral iron bis(oxazoline) and pyridine-2,6-bis(oxazoline) catalysts through their most prominent and innovative uses in asymmetric catalysis, especially in Lewis acid and oxidation catalysis.

scholarly journals A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

2010 ◽  
Vol 6 ◽  
Author(s):  
Magnus Rueping ◽  
Boris J Nachtsheim
Keyword(s):  
Green Chemistry ◽  
Asymmetric Catalysis ◽  
Lewis Acid ◽  
Environmentally Benign ◽  
Short Introduction ◽  
New Developments ◽  
Wide Range ◽  
Benzyl Halides ◽  
Allyl Alcohols ◽  
Definition Of

The development of efficient Friedel–Crafts alkylations of arenes and heteroarenes using only catalytic amounts of a Lewis acid has gained much attention over the last decade. The new catalytic approaches described in this review are favoured over classical Friedel–Crafts conditions as benzyl-, propargyl- and allyl alcohols, or styrenes, can be used instead of toxic benzyl halides. Additionally, only low catalyst loadings are needed to provide a wide range of products. Following a short introduction about the origin and classical definition of the Friedel–Crafts reaction, the review will describe the different environmentally benign substrates which can be applied today as an approach towards greener processes. Additionally, the first diastereoselective and enantioselective Friedel–Crafts-type alkylations will be highlighted.

Recent progress in Lewis acid-Lewis base bifunctional asymmetric catalysis

2005 ◽  
Vol 77 (12) ◽  
pp. 2047-2052 ◽  
Author(s):  
Motomu Kanai ◽  
Nobuki Kato ◽  
Eiko Ichikawa ◽  
Masakatsu Shibasaki
Keyword(s):  
Asymmetric Catalysis ◽  
Lewis Acid ◽  
Recent Progress ◽  
Lewis Base ◽  
Pyridine Derivatives ◽  
Asymmetric Catalysts ◽  
Strecker Reaction

Two enantioselective cyanation reactions, the Strecker reaction of ketoimines and the Reissert reaction of pyridine derivatives, promoted by Lewis acid-Lewis base bifunctional asymmetric catalysts are described.

Deconjugated butenolide: a versatile building block for asymmetric catalysis

2020 ◽  
Vol 49 (18) ◽  
pp. 6755-6788 ◽  
Author(s):  
Abhijnan Ray Choudhury ◽  
Santanu Mukherjee
Keyword(s):  
Asymmetric Catalysis ◽  
Building Block ◽  
Enantioselective Synthesis ◽  
Asymmetric Reactions ◽  
Comprehensive Overview ◽  
Catalytic Asymmetric ◽  
Catalytic Asymmetric Reactions

Deconjugated butenolides have emerged as a popular synthon for the enantioselective synthesis of γ-lactones. This review provides a comprehensive overview on the catalytic asymmetric reactions of deconjugated butenolides reported till date.

Enantiospecific total syntheses of meroterpenoids (−)-F1839-I and (−)-corallidictyals B and D

2017 ◽  
Vol 15 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Dattatraya H. Dethe ◽  
Balu D. Dherange ◽  
Saghir Ali ◽  
Mahesh M. Parsutkar
Keyword(s):  
Natural Products ◽  
Lewis Acid ◽  
Bond Formation ◽  
Environmentally Benign ◽  
Formation Reaction ◽  
Total Syntheses

Enantiospecific total syntheses of spiromeroterpenoid natural products (−)-F1839-I and (−)-corallidictyals B and D were achieved using the environmentally benign and highly atom economical Lewis acid catalysed Friedel–Crafts reaction and a highly regio- and stereoselective spirocyclic C–O bond formation reaction.

scholarly journals Asymmetric reactions in continuous flow

2009 ◽  
Vol 5 ◽  
Author(s):  
Xiao Yin Mak ◽  
Paola Laurino ◽  
Peter H Seeberger
Keyword(s):  
Asymmetric Synthesis ◽  
Asymmetric Catalysis ◽  
Continuous Flow ◽  
Asymmetric Reactions ◽  
Heterogeneous Asymmetric Catalysis

An overview of asymmetric synthesis in continuous flow and microreactors is presented in this review. Applications of homogeneous and heterogeneous asymmetric catalysis as well as biocatalysis in flow are discussed.

scholarly journals Lewis acid enhancement by hydrogen-bond donors for asymmetric catalysis

Science ◽  
2017 ◽  
Vol 358 (6364) ◽  
pp. 761-764 ◽  
Author(s):  
Steven M. Banik ◽  
Anna Levina ◽  
Alan M. Hyde ◽  
Eric N. Jacobsen
Keyword(s):  
Hydrogen Bond ◽  
Catalytic Activity ◽  
Asymmetric Catalysis ◽  
Small Molecule ◽  
Lewis Acid ◽  
Low Temperatures ◽  
Noncovalent Interactions ◽  
Enantioselective Reactions ◽  
Acidic Complex ◽  
Hydrogen Bond Donors

Small-molecule dual hydrogen-bond (H-bond) donors such as ureas, thioureas, squaramides, and guanidinium ions enjoy widespread use as effective catalysts for promoting a variety of enantioselective reactions. However, these catalysts are only weakly acidic and therefore require highly reactive electrophilic substrates to be effective. We introduce here a mode of catalytic activity with chiral H-bond donors that enables enantioselective reactions of relatively unreactive electrophiles. Squaramides are shown to interact with silyl triflates by binding the triflate counterion to form a stable, yet highly Lewis acidic, complex. The silyl triflate-chiral squaramide combination promotes the generation of oxocarbenium intermediates from acetal substrates at low temperatures. Enantioselectivity in nucleophile additions to the cationic intermediates is then controlled through a network of noncovalent interactions between the squaramide catalyst and the oxocarbenium triflate.

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