Owing to their favorable molecular topology, atropisomers represent particularly valuable chiral scaffolds for numerous applications throughout academic research and industry. Nevertheless, whereas various well-established catalyst-controlled methodologies allow addressing stereocenter configuration, efficient procedures prepare axially compounds in high isomeric purity are still scarce. Complementary the comprehensive reviews area, this Perspective features representative advances...

Abstract Axially chiral compounds are of significant importance in modern synthetic chemistry and particularly valuable drug discovery development. Nonetheless, current approaches for the preparation pure atropisomers often prove tedious. We demonstrate here a method that efficiently transfers stereochemical information secondary amine organocatalyst into axial chirality tri‐ ortho ‐substituted biaryls. An aromatic ring is formed during dehydration step described aldol condensation cascade,...

The gauche effect that is induced upon reversible formation of an iminium ion (see structure: green F, blue N) provides a powerful method for the preorganization transient intermediates are central to secondary amine catalyzed processes. This phenomenon has been exploited in design novel organocatalyst and showcased stereoselective epoxidation alpha,beta-unsaturated aldehydes.

Abstract Strategien zum molekularen Design, die von den intrinsischen stereoelektronischen und elektrostatischen Effekten fluorierter organischer Moleküle profitieren, sind bisher hauptsächlich auf bioorganische Chemie beschränkt. Bei vielen konformativen Fluoreffekten handelt es sich zwar um akademische Kuriositäten ohne unmittelbare Anwendung, Renaissance der Organokatalyse bietet allerdings Möglichkeit zur Erforschung vieler dieser ausführlich beschriebenen Phänomene Präorganisation. In...

Trick the iminium! The concept of cyclopropyl iminium activation for organocatalytic desymmetrization meso-cyclopropylcarbaldehydes is presented. A combination nucleophilic and electrophilic chlorinating reagents leads to a formal addition Cl2 across one bonds giving access 1,3-dichlorides in an enantioselective, catalytic fashion. Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made...

Abstract Structurally well‐defined oligomers are fundamental for the functionality of natural molecular systems and key design synthetic counterparts. Herein, we describe a strategy efficient synthesis individual stereoisomers 1,2‐naphthylene by iterative building block additions consecutive stereoselective arene‐forming aldol condensation reactions. The catalyst‐controlled atropoenantioselective substrate‐controlled atropodiastereoselective reaction provide structurally distinct ter‐...

The design, modular synthesis and applications of aminoacridinium photoredox catalysts (<italic>e.g.</italic>R¹= NMe₂) with a broad range redox properties compatibility complex substrates reaction mixtures are highlighted in this feature article.

Molecular scaffolds with multiple rotationally restricted bonds allow a precise spatial positioning of functional groups. However, their synthesis requires methods addressing the configuration each stereogenic axis. We report here catalyst-stereocontrolled atropisomeric multiaxis systems enabling divergence from prevailing stereochemical reaction path. By using ion-pairing catalysts in arene-forming aldol condensations, strong substrate-induced stereopreference can be overcome to provide...

Abstract The increasing awareness of the importance amide atropisomers prompts development novel strategies for their selective preparation. Described herein is a method enantioselective synthesis atropisomeric aromatic amides by an amine‐catalyzed arene‐forming aldol condensation. high reactivity glyoxylic substrates enables remarkably efficient construction new ring, which proceeds within minutes at ambient temperature to afford products with excellent stereoselectivity. rotational...

Control over redox states and spin multiplicity of photocatalysts throughout a catalytic cycle is crucial for selective efficient photocatalytic processes. However, the rational design often hampered by mechanistic complexity low modularity catalyst structure. Herein, we demonstrate photophysical study diverging pathways that guides organic acridinium catalysts to complement polypyridyl transition metal systems. A combined halogen–metal exchange/directed ortho-metalation provides reagents...

ConspectusContradictory to the first intuitive impression that forging putatively flat aromatic rings evades stereoisomerism, a striking variety of atropisomeric compounds are conceivable by formation arenes, offering captivating avenues for catalyst-controlled stereoselective strategies. Since assembled products contain one or several rotationally restricted single bonds characterized especially well defined molecular architectures, they distinctly suitable numerous pertinent applications....

Abstract The structures of iminium salts formed from diarylprolinol or imidazolidinone derivatives and α , β ‐unsaturated aldehydes have been studied by X‐ray powder diffraction ( Fig. 1 ), single‐crystal analyses Table NMR spectroscopy Tables 2 3, Figs. 2–7 DFT calculations Helv. Chim. Acta 2009 92 1, 1225, 2010 93 1; Angew. Chem., Int. Ed. 48 3065). Almost all this type exist in solution as diastereoisomeric mixtures with E )‐ Z )‐configured + NC bond geometries. In study, )/( ) ratios...

Abstract Axial‐chirale Verbindungen sind in der modernen Synthesechemie von zentraler Bedeutung und für die Arzneimittelentwicklung unentbehrlich. Der Zugang zu Atropisomeren reiner Form erweist sich jedoch oft als sehr aufwendig. Hier zeigen wir eine atropselektive Synthesemethode, welche stereochemische Information eines sekundären Amin‐Organokatalysators effizient axiale Chiralität tri‐ ortho ‐substituierten Biarylen überträgt. Die beschriebene Aldolkondensationskaskade führt während...

Despite the manifold use of heterocyclic fluorophores, only a fraction desired dye diversity can be accessed by contemporary synthetic approaches. Herein, we describe modular method that converts various carboxylic acid esters directly into broad spectrum heteroanthrylium fluorophores. The double addition heteroatom-bridged 1,5-bifunctional organomagnesium reagents to leads formation acridinium, xanthylium, and SiR fluorophores after dehydrative acidic work-up. This one-step provides access...

Abstract A strategy for the remote central‐to‐axial chirality conversion by simultaneous planarization of an encoding and a transient stereocenter is presented. Based on diastereoselective double addition chiral 1,5‐bifunctional organomagnesium alkoxide reagent to broad range aryl ester substrates, axially biaryls are directly obtained upon in situ reduction. Various structurally distinct atropisomeric biaryl silanes that serve as valuable anion surrogates accessible one step with e.r....

Simultaneous control over the configuration of multiple stereocenters is accomplished by numerous catalytic methods, providing a reliable basis for synthesis stereochemically complex targets in isomerically defined form. In contrast, addressing configurations stereogenic axes with diastereodivergent catalyst thus far only possible stepwise approaches. Herein we now describe that all four stereoisomers atropisomeric two-axis systems are directly tractable assembling central aromatic unit...

Fluorine in charge! The fluorine–iminium ion gauche effect has been exploited the design of conformational probes for organocatalysis (see scheme). Stabilizing hyperconjugative [σCH→σ*CF] and/or electrostatic [N+⋅⋅⋅Fδ−] interactions render CF bond an excellent steering group controlling molecular topology without introducing additional steric constraints.

Cellular drug delivery can improve efficacy and render intracellular pathogens susceptible to compounds that cannot permeate cells. The transport of physiologically active across membranes into target cells be facilitated by cell-penetrating peptides (CPPs), such as oligoarginines. Here, we investigated whether the fosmidomycin improved combination with CPP octaarginine. Fosmidomycin is an antibiotic inhibits second reaction in nonmevalonate pathway isoprenoid biosynthesis, essential for...

The fundamental role that aldol chemistry adopts in various disciplines, such as stereoselective catalysis or the biosynthesis of aromatic polyketides, illustrates its exceptional versatility. On one hand, numerous addition reactions reliably transfer stereochemical information from catalysts into valuable products. other countless polyketide natural products are produced by an ingenious biosynthetic machinery based on arene-forming condensations. With aim complementing methodology controls...