Abstract Axially chiral styrenes bearing a axis between sterically non-congested acyclic alkene and an aryl ring are difficult to prepare due low rotational barrier of the axis. Disclosed here is N -heterocyclic carbene (NHC) catalytic asymmetric solution this problem. Our reaction involves ynals, sulfinic acids, phenols as substrates with NHC catalyst. Key steps involve selective 1,4-addition anion acetylenic acylazolium intermediate sequential E -selective protonation set up affords...

A carbene-catalyzed reductive coupling reaction of carboxylic esters and substituted Hantzsch is disclosed. Key steps this include one-electron reduction a carbene catalyst-bound acyl azolium intermediate to generate the corresponding radical for subsequent alkylation reactions. The promoted by irradiation with visible light without involvement transition-metal photocatalysts. Mechanistic studies suggest that direct photoexcitation in situ formed likely responsible light-induced...

Abstract The total synthesis of the tunicate metabolite mandelalide A and correction its originally assigned stereochemistry are reported. Key features convergent, fully stereocontrolled route include use a Prins cyclization for diastereoselective construction tetrahydropyran subunit, Rychnovsky–Bartlett preparation tetrahydrofuran moiety, Suzuki coupling, Horner–Wadsworth–Emmons macrocyclization, glycosylation to append L ‐rhamnose‐derived pyranoside.

Disclosed herein is the first carbene-organocatalyzed asymmetric addition of phosphine nucleophiles to in situ generated α,β-unsaturated acyl azolium intermediates. Our reaction enantioselectively constructs carbon-phosphine bonds and prepares chiral phosphines with high optical purities. The products are suitable for transforming ligands or catalysts applications catalysis. diarylalkyl trialkyl from our catalytic reactions, air-sensitive reactive nature, can be trapped (and stored) their...

A facile copper-catalyzed, base-controlled cyclization reaction has been developed for the synthesis of 9-membered cycloalkyne and 6-membered heterocycle sultams under mild conditions. This protocol utilizes a copper-catalyzed intramolecular A3 (alkyne–aldehyde–amine) coupling to efficiently synthesize in yields up 90%. Alternatively, by substituting NaHCO3 with DBU, achieves selective deprotection N-propargyl group, thereby facilitating formation heterocyclic sultams, also high yields.

Lagunamide D is a structurally distinct 26-membered cytotoxic cyclic depsipeptide, originally isolated from marine cyanobacterium. It exhibits potent antiproliferative activity in the low nanomolar range against A549 human lung adenocarcinoma cells and HCT116 colon cancer cells. A significant challenge associated with lagunamide its propensity for intramolecular acyl migration, which leads to formation of contracted 24-membered analog, D′. This structural rearrangement complicates isolation,...

A second-generation formal synthesis of psymberin was successfully developed, incorporating several notable advancements. Central to this approach is a challenging Heck reaction, which effectively unites sterically demanding aryl moiety with terminal alkene, showcasing the method's robustness under these conditions. Additionally, construction isocoumarin scaffold accomplished through Pd-mediated cyclization, underscoring efficiency and precision key transformation. Notably, improved route De...

By employing a simple, inexpensive, and transition-metal-free oxidation system, secondary C–H bonds in series of phthaloyl protected primary amines amino acid derivatives were oxidized to carbonyls with good regioselectivities. This method could also be applied oxidize tertiary modify synthetic dipeptides.

Polarity inversion of arylidene hydrazones to react with bromoenals <italic>via</italic> carbene organic catalysis is disclosed. The reaction enantioselectively affords 6-aryl-4,5-dihydropyridazinones and related drugs proven commercial applications.

The first total synthesis of neurotoxic cyclodepsipeptide hoiamide A (1) has been accomplished. features the use an Evans–Tishchenko fragment coupling between a five-stereogenic-center-containing β-hydroxyketone and chiral aldehyde derived from threonine.

CXCR7 plays an emerging role in several physiological processes. A linear peptide, amantamide (1), was isolated from marine cyanobacteria, and the structure determined by NMR mass spectrometry. The total synthesis achieved solid-phase method. After screening two biological target libraries, 1 identified as a selective agonist. activation of could provide basis for developing CXCR7-targeted therapeutics deciphering different diseases.

A carbene-catalyzed highly regioselective and enantioselective 1,4-addition reaction between isothioureas enals has been achieved under oxidative conditions.

The first total synthesis of asperphenins A and B has been accomplished in a concise, highly stereoselective fashion from commercially available materials (15 steps, 9.7% 14.2% overall yields, respectively). convergent route featured the judicious choice protecting groups, fragment assembly strategy late-stage iron-catalyzed Wacker-type selective oxidation an internal alkene to corresponding ketone.

Abstract The total synthesis of the tunicate metabolite mandelalide A and correction its originally assigned stereochemistry are reported. Key features convergent, fully stereocontrolled route include use a Prins cyclization for diastereoselective construction tetrahydropyran subunit, Rychnovsky–Bartlett preparation tetrahydrofuran moiety, Suzuki coupling, Horner–Wadsworth–Emmons macrocyclization, glycosylation to append L ‐rhamnose‐derived pyranoside.

The first total syntheses of cyclic depsipeptides colletopeptide A and colletotrichamide A, have been accomplished. key advanced intermediate, a tridepsipeptide derivative, was constructed using sequence transformations that features asymmetric Brown crotylation, cross metathesis, Yamaguchi esterification, ozonolysis, macrolactamization. late-stage incorporation the mannose fragment completed synthesis desilylation common intermediate gave rise to which led unambiguous confirmation absolute...

A concise approach for rapid assembly of multicyclic isoquinoline scaffolds from pyridines and β-ethoxy α,β-unsaturated carbonyl compounds was developed, which enabled the formal total synthesis fredericamycin A.

Abstract Disclosed herein is the first carbene‐organocatalyzed asymmetric addition of phosphine nucleophiles to in situ generated α,β‐unsaturated acyl azolium intermediates. Our reaction enantioselectively constructs carbon–phosphine bonds and prepares chiral phosphines with high optical purities. The products are suitable for transforming ligands or catalysts applications catalysis. diarylalkyl trialkyl from our catalytic reactions, air‐sensitive reactive nature, can be trapped (and stored)...

The stereochemistry of aurantinin was determined by spectroscopic and computational analysis with the assistance biosynthetic studies. latter method provided critical evidence for assignment configuration 3-ketosugar moiety.

Potassium cocoyl glycinate, a kind of amino acid surfactant, is widely used as major component for facial cleansing. However, the interaction between surfactants and compounds in stratum corneum has been suggested contributing factor to their potential skin irritancy. This study aimed effects adding surfactants, polymers, lipids active substances on diminishing irritation caused by glycinate. Zein test Hemolysis enabled identification proteins cells studied binary systems. The critical...

A stereocontrolled synthesis of the tetrahydrofuran/α-hydroxy lactone fragment mandelalide B has been accomplished. The features a Horner-Wadsworth-Emmons assembly strategy and highly stereospecific iodine-induced cyclization.