Complete Field Guide to Asymmetric BINOL-Phosphate Derived Brønsted Acid and Metal Catalysis: History and Classification by Mode of Activation; Brønsted Acidity, Hydrogen Bonding, Ion Pairing, and Metal Phosphates

Iron Catalysis in Organic Synthesis

Isatins As Privileged Molecules in Design and Synthesis of Spiro-Fused Cyclic Frameworks

Flow chemistry involves the use of channels or tubing to conduct a reaction in a continuous stream rather than in a flask Flow equipment provides chemists with unique control over reaction parameters enhancing reactivity or in some cases enabling new reactions This relatively young technology has received a remarkable amount of attention in the past decade with many reports on what can be done in flow Until recently, however, the question, “Should we do this in flow?” has merely been an afterthought This review introduces readers to the basic principles and fundamentals of flow chemistry and critically discusses recent flow chemistry accounts

The Hitchhiker's Guide to Flow Chemistry

The legacy of Gilbert Newton Lewis (1875-1946) pervades the lexicon of chemical bonding and reactivity. The power of his concept of donor-acceptor bonding is evident in the eponymous foundations of electron-pair acceptors (Lewis acids) and donors (Lewis bases). Lewis recognized that acids are not restricted to those substances that contain hydrogen (Bronsted acids), and helped overthrow the "modern cult of the proton". His discovery ushered in the use of Lewis acids as reagents and catalysts for organic reactions. However, in recent years, the recognition that Lewis bases can also serve in this capacity has grown enormously. Most importantly, it has become increasingly apparent that the behavior of Lewis bases as agents for promoting chemical reactions is not merely as an electronic complement of the cognate Lewis acids: in fact Lewis bases are capable of enhancing both the electrophilic and nucleophilic character of molecules to which they are bound. This diversity of behavior leads to a remarkable versatility for the catalysis of reactions by Lewis bases.

Lewis Base Catalysis in Organic Synthesis

The invention provides a method for synthesizing a gamma-nitropyrazole amide compound under asymmetric catalysis. According to the method, nitroalkane and alpha,beta-unsaturated pyrazole amide are used as raw materials, a complex formed by chiral amine oxide and a rare earth metal compound is used as a catalyst, and a 4angstrom molecular sieve is used as an additive; and the chiral gamma-nitropyrazole amide compound obtained after reaction has yield as high as 99% and enantiomeric excess of as high as 99% ee. A catalysis system used in the invention has the advantages of simple operation, mild reaction conditions, no acid-base additive, convenience in product purification, high yield, high enantioselectivity, accordance with requirements of atom economy and good industrial application prospect; and the gamma-nitropyrazole amide compound obtained after reaction can be simply converted into molecules with physiological activity in a chemical way.

Method for synthesizing gamma-nitropyrazole amide compound under asymmetric catalysis

An efficient asymmetric aza-Henry reaction of isatin-derived ketimines has been achieved by using a chiral guanidine–amide organocatalyst. A series of 3-substituted 3-amino-2-oxindoles was obtained with excellent results (up to 99% yield, 94% ee). Other functionalized derivatives were also conveniently transformed. This metal-free system was convenient, practical, and insensitive to air and moisture. On the basis of the crystal structure of the catalyst and NMR spectra analysis, a bifunctional catalytic model was suggested to explain the origin of the asymmetric process.

Chiral Bifunctional Guanidine-Catalyzed Enantioselective Aza-Henry Reaction of Isatin-Derived Ketimines.

A synthesis method of γ-nitropyrazole amide compound through asymmetrical catalyzing technique is provided, a nitroalkane and an α,β-unsaturated pyrazole amide are applied as the raw material, a complex formed by a chiral amine oxide with a rare earth metal compound is served as the catalyst, a 4 Å molecular sieve is served as an additive, the γ-nitropyrazole amide compound can be obtained with a yield more than 99% and enantiomeric excess more than 99% ee. The catalytic system not only has the advantages of simple operation, mild reaction conditions, requiring no acid/base additives, convenient product purification, high yield and enatioselectivity, compliance with green atomic economy, and promising prospects for industrial application, but also allows the obtained γ-nitropyrazole amide compound to undergo some simple chemical conversions to produce some molecules having physiological activities.

Asymmetrically catalyzed synthesis method of nitropyrazole amide compound

Recent Advances on Catalytic Enantioselective Protonation for Construction of α-Tertiary Carbonyl Compounds

Asymmetric Activation of tropos 2,2′‐Biphenol with Cinchonine Generates an Effective Catalyst for the Asymmetric Strecker Reaction of N‐Tosyl‐Protected Aldimines and Ketoimines.

Xiaohua Liu

Papers

Method for synthesizing gamma-nitropyrazole amide compound under asymmetric catalysis

Chiral Bifunctional Guanidine-Catalyzed Enantioselective Aza-Henry Reaction of Isatin-Derived Ketimines.

Asymmetrically catalyzed synthesis method of nitropyrazole amide compound

Recent Advances on Catalytic Enantioselective Protonation for Construction of α-Tertiary Carbonyl Compounds

Asymmetric Activation of tropos 2,2′‐Biphenol with Cinchonine Generates an Effective Catalyst for the Asymmetric Strecker Reaction of N‐Tosyl‐Protected Aldimines and Ketoimines.