Abstract Soft Lewis acid/Brønsted base cooperative catalysts have enabled direct catalytic asymmetric vinylogous conjugate addition of α,β‐ and β,γ‐unsaturated butyrolactones to α,β‐unsaturated thioamides with perfect atom economy. When using α‐angelica lactone its derivatives as pronucleophiles, little 0.5 mol % catalyst loading was sufficient complete the reaction necessary construct consecutive tri‐ tetrasubstituted stereogenic centers in a highly diastereo‐ enantioselective fashion.

Sulfone motifs play important roles in bioactive compounds and functional materials. The development of efficient methodologies for constructing sulfonyl-containing has thus attracted considerable attention. Here, we introduce a protocol the preparation alkyl aryl sulfones under mild conditions. This employs β-thioamide sulfone as novel motif donor. It forms sulfinates situ basic conditions, which then undergo cross-coupling with intermediates that were generated from ligand-free...

Abstract Optically active vicinal diamines are versatile chiral building blocks in organic synthesis. A soft Lewis acid/hard Brønsted base cooperative catalyst allows for an efficient stereoselective coupling of N ‐alkylidene‐α‐aminoacetonitrile and ketimines to access this class compounds bearing consecutive tetra‐ trisubstituted stereogenic centers. The strategic use a basic thiophosphinoyl group is the key promoting reaction, aliphatic serve as suitable substrates with little 3 mol % loading.

α,α-Disubstituted α-amino acids have attracted increasing interest due to their potential utility as building blocks of unnatural peptides. Herein we document an enantioselective entry this class compounds through the direct catalytic addition acetonitrile α-iminoesters bearing N-thiophosphinoyl group. Chiral N-heterocyclic carbene complexes [Ir(cod)(OMe)]2 catalytically rendered generation α-cyanocarbanions from in combination with Barton's base, followed by imino carbonyl group, delivering...

Abstract We report a direct catalytic asymmetric Mannich‐type addition of α,β‐unsaturated γ‐butyrolactam to α‐ethoxycarbonyl ketimines promoted by soft Lewis acid/Brønsted base cooperative catalyst. A thiophosphinoyl group on the nitrogen was crucial for both electrophilic activation and α‐addition γ‐butyrolactams. The obtained aza‐Morita–Baylis–Hillman‐type products bear an α‐amino acid architecture with tetra‐substituted stereogenic center.

Abstract Pentamidine and melarsoprol are primary drugs used to treat the lethal human sleeping sickness caused by parasite Trypanosoma brucei . Cross-resistance these two has recently been linked aquaglyceroporin 2 of trypanosome (TbAQP2). TbAQP2 is first member aquaporin family described as capable drug transport; however, underlying mechanism remains unclear. Here, we present cryo-electron microscopy structures bound pentamidine or melarsoprol. Our structural studies, together with...

The Arabidopsis thaliana aluminum-activated malate transporter 9 (AtALMT9) functions as a vacuolar chloride channel that regulates the stomatal aperture. Here, we present cryoelectron microscopy (cryo-EM) structures of AtALMT9 in three distinct states. forms dimer, and pore is lined with four positively charged rings. apo-AtALMT9 state shows putative endogenous citrate obstructing pore, where two W120 constriction residues enclose gate radius approximately 1.8 Å, representing an open state....

Abstract The non‐isothermal crystallization behavior, the kinetics, activation energy and morphology of isotactic polypropylene (iPP) with varying content β‐nucleating agent were investigated using differential scanning calorimetry (DSC) electron microscopy (SEM). DSC results showed that Avrami equation modified by Jeziorny a method developed Mo co‐workers could be successfully used to describe process nucleated iPPs. values n α‐ β‐nucleated iPPs corresponded tridimensional growth...

Abstract Soft Lewis acid/Brønsted base cooperative catalysts have enabled direct catalytic asymmetric vinylogous conjugate addition of α,β‐ and β,γ‐unsaturated butyrolactones to α,β‐unsaturated thioamides with perfect atom economy. When using α‐angelica lactone its derivatives as pronucleophiles, little 0.5 mol % catalyst loading was sufficient complete the reaction necessary construct consecutive tri‐ tetrasubstituted stereogenic centers in a highly diastereo‐ enantioselective fashion.

An iterative direct aldol reaction using a C3 propionate unit as an donor offers expeditious access to polyketide assembly in highly diastereo- and enantioselective manner. all-syn array with four consecutive stereogenic centers was efficiently constructed by of thiopropionamide via soft Lewis acid/hard Brønsted base cooperative catalysis. This strategy led synthesis (−)-membrenone A B.

Sulfone motifs play important roles in bioactive compounds and functional materials. The development of efficient methodologies for constructing sulfonyl-containing has thus attracted considerable attention. Here, we introduce a protocol the preparation alkyl aryl sulfones under mild conditions. This employs -thioamide sulfone as novel motif donor. It forms sulfinates situ basic conditions, which then undergo cross-coupling with intermediates that were generated from ligand-free...

Abstract Ein zentrales Ziel der chemischen Biologie ist die Entwicklung von molekularen Sonden, grundlegende Untersuchungen zellulärer Systeme ermöglichen. In Hierarchie bioaktiver Moleküle nehmen sogenannten Ionophore eine unspektakuläre Position ein, wobei typische Charakterisierungen “unspezifisch” und “toxisch” sind. Tatsächlich führt bloße Möglichkeit, dass ein Kandidatenmolekül “Ionophoraktivität” besitzt, dazu, es aus weiteren Studien entfernt wird; sind, einer chemobiologischen...

Abstract Optically active vicinal diamines are versatile chiral building blocks in organic synthesis. A soft Lewis acid/hard Brønsted base cooperative catalyst allows for an efficient stereoselective coupling of N ‐alkylidene‐α‐aminoacetonitrile and ketimines to access this class compounds bearing consecutive tetra‐ trisubstituted stereogenic centers. The strategic use a basic thiophosphinoyl group is the key promoting reaction, aliphatic serve as suitable substrates with little 3 mol % loading.

The polyether ionophores are complex natural products capable of transporting cations across biological membranes. Many family members possess highly potent antimicrobial activity and a few selected compounds have ability to target particularly aggressive cancer cells. Despite these interesting perspectives, detailed understanding the cellular mode-of-action is generally lacking. In principle, broad mapping structure-activity relationships several activities could provide mechanistic...

Sulfone plays an important role in our daily lives; developing methodologies to construct it has attracted considerable attention. Here, we introduce a protocol for the preparation of alkyl aryl sulfones under mild conditions. This employs -thioamide sulfone as novel motif donor. It forms sulfinates situ basic conditions, which then undergoes cross-coupling with intermediates that were generated from ligand-free copper-catalyzed cyclopropenes (CPEs) ring-opening.

Comprehensive Summary Although it offers a direct route to access synthetically valuable α‐chiral primary amines, asymmetric transfer hydrogenation of NH imines has been rarely studied, due in large part the inaccessibility and instability imines. Herein, we report Rh‐catalyzed kind novel stable which are prepared via condensation easily available sulfonylated 2’‐aminoacetophenones with 3 methanol. With this method, enantioenriched chiral 2‐(1‐aminoalkyl)anilines, privileged pharmacore...

The polyether ionophores are complex natural products capable of transporting cations across biological membranes. Many family members possess highly potent antimicrobial activity and a few selected compounds have ability to target particularly aggressive cancer cells. Despite these interesting perspectives, detailed understanding the cellular mode-of-action is generally lacking. In principle, broad mapping structure-activity relationships several activities could provide mechanistic...