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 first catalytic enantioselective Roskamp reaction of α-alkyl-α-diazoesters with aromatic aldehydes was realized using a simple chiral N,N′-dioxide−scandium(III) complex. Remarkably, with 0.05 mol % catalyst, the reaction was performed well over a series of substrates, giving the desired products chemoselectively in excellent yields (up to 99%) and enantioselectivities (up to 98% ee) under mild conditions. This protocol provides a promising method for the synthesis of chiral α-alkyl-β-keto esters and 1,3-diols.

Catalytic Asymmetric Roskamp Reaction of α‐Alkyl‐α‐diazoesters with Aromatic Aldehydes: Highly Enantioselective Synthesis of α‐Alkyl‐β‐keto Esters.

The reaction of aromatic and aliphatic aldehydes, 2-aminophenols and cyclopentadiene (III) is catalyzed by Sc(OTf)3 and a chiral N,N′-dioxide catalysts to afford the target tricyclic products with high yields and selectivities.

Asymmetric three-component inverse electron-demand aza-Diels–Alder reaction: efficient synthesis of ring-fused tetrahydroquinolines

Asymmetric Three-Component Inverse Electron-Demand Aza-Diels—Alder Reaction: Efficient Synthesis of Ring-Fused Tetrahydroquinolines.

A series of amide-based bifunctional organocatalysts have been utilized in asymmetric reactions. Prolinamide analogues have been designed to catalyze asymmetric reactions via enamine intermediates with the assistance of tunable hydrogen bonding. In addition, the combination of various Lewis base functional groups, such as guanidine, N-oxide and phosphane, with an amide moiety have also constituted efficient bifunctional organocatalysts with unique reactivity and selectivity.

Amide-Based Bifunctional Organocatalysts in Asymmetric Reactions

The first example of oxyamination of azlactones with oxaziridines is realized using a chiral bisguanidinium salt with non-coordinating anion.

Xiaohua Liu

Papers

Catalytic Asymmetric Roskamp Reaction of α‐Alkyl‐α‐diazoesters with Aromatic Aldehydes: Highly Enantioselective Synthesis of α‐Alkyl‐β‐keto Esters.

Asymmetric three-component inverse electron-demand aza-Diels–Alder reaction: efficient synthesis of ring-fused tetrahydroquinolines

Asymmetric Three-Component Inverse Electron-Demand Aza-Diels—Alder Reaction: Efficient Synthesis of Ring-Fused Tetrahydroquinolines.

Amide-Based Bifunctional Organocatalysts in Asymmetric Reactions

Organocatalytic Oxyamination of Azlactones: Kinetic Resolution of Oxaziridines and Asymmetric Synthesis of Oxazolin-4-ones.