Intramolecular spatial charge transfer (ISCT) plays a critical role in determining the optical and charge transport properties of thermally activated delayed fluorescence (TADF) materials. Herein, a new donor/acceptor-type TADF compound based on rigid dibenzothiophene sulfone (DBTS) moiety, STF-DBTS, was designed and synthesized. Fluorene unit was used as a rigid linker to position the rigid acceptor and donor subunit in close vicinity with control over their spacing and molecular structure and to achieve high photoluminescence quantum yield (∼53%) and TADF property. For comparison purposes, we constructed the more flexible STF-DPS with a less rotationally constrained diphenylsulphone (DPS) acceptor instead of the rigid DBTS units, and STF-DPS showed no TADF properties and lower PLQY (16.0%). Organic light-emitting diodes (OLEDs) based on STF-DBTS achieve an external quantum efficiency (EQE) of 10.3% at 488 nm, which is a fivefold improvement in EQE with respect to STF-DPS.The binaphthyl stabilized palladium nanoparticles (Pd-BNP) catalyzed single-step, stereoselective domino synthesis of symmetrically and unsymmetrically all-carbon tetrasubstituted olefin containing oxindoles from readily accessible anilides has been developed. The Pd-BNP catalyst showed a wide range of functional group tolerance that enabled building a library of heteroaromatics. This reusable Pd catalyst reflected its utility in the synthesis of biologically important AMP-activated protein kinase deprived of any metal Pd contamination. The nanocatalyst was easily recovered and reused five times without any appreciable loss in particle size or catalytic activity.Lewis acid-catalyzed rearrangements of 4,5-dihydro-1,3-dioxepines have been investigated. Rearrangement of vinyl acetals under a variety of conditions resulted in cis- and trans-2,3-disubstituted tetrahydrofuran derivatives in a highly stereoselective manner. Rearrangements at lower temperatures typically provided the cis-2,3-disubstituted tetrahydrofuran carbaldehydes. At higher temperatures, the corresponding trans-2,3-disubstituted tetrahydrofuran carbaldehydes are formed. The requisite substrates for the vinyl acetal rearrangement were synthesized via ring-closing olefin metathesis of bis(allyoxy)methyl derivatives using Grubbs second-generation catalyst followed by olefin isomerization using a catalytic amount of RuCl2(PPh3)3. We examined the substrate scope using substituted aromatic and aliphatic derivatives. Additionally, the rearrangement was utilized in the synthesis of a stereochemically-defined bis-tetrahydrofuran (bis-THF) derivative, which is one of the key structural elements of darunavir, an FDA-approved drug for the treatment of HIV/AIDS.Multitarget synthetic strategies to access novel photochromic 3H-naphtho[2,1-b]pyrans decorated with pyridyl units are described. The new pyridyl-substituted 3H-naphtho[2,1-b]pyrans display good photochromic properties with reversible generation of photomerocyanines, which exhibit mainly orange/red hues. Photochromic parameters including photocolorability and persistence of color vary tremendously on structural modification of the naphthopyran core.An environmentally benign system for the direct alkylation of lawsones and 4-hydroxycoumarins with alcohols in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) is reported. The reaction proceeded smoothly via a dehydrative cross-coupling process by utilizing the unique properties of HFIP. A variety of alkylated products and subsequent one-pot cyclized products (pyranonaphthoquinones and pyranocoumarins) could be obtained in 40-93% yields.The title compounds were prepared, and their reactivity was studied upon sensitized irradiation at λ = 420 nm. Thioxanthen-9-one was employed as the sensitizer at a loading of 10 mol % in small-scale reactions and of 2.5 mol % on a larger scale. Cyclohex-2-enones substituted by a 2'-propenyloxy, 2'-butenyloxy, 2'-pentenyloxy, or 2'-methyl-2'-propenyloxy group in the 2-position gave the products of an intramolecular [2 + 2] photocycloadditon. The reaction proceeded with high regioselectivity (crossed product) and perfect diastereoselectivity (nine examples, 34-99% yield). If the olefin in the tether was trisubstituted (3'-methyl-2'-butenyloxy), no cycloaddition was observed. Rather, a cyclization with subsequent hydrogen abstraction occurred (three examples, 65-86% yield). The results are consistent with a reaction course via a triplet enone intermediate and the formation of a 1,4-diradical by an initial cyclization. The analogous cyclopent-2-enones were less prone to an intramolecular reaction. Instead, decomposition or intermolecular [2 + 2] photocycloaddition reactions prevailed. In the latter event, two main products were identified (three examples, 30-43% yield), resulting either from a head-to-head [2 + 2]-photodimerization or from a twofold [2 + 2] photocycloaddition of the enone to the olefin. The latter reaction sequence generated pentacyclic products with a central [1,5]dioxocane ring. The structure assignment of the two product types was corroborated by a single-crystal X-ray analysis.A novel three-component γ-iminolactonization reaction was developed, which relied on the C-C/C-O bond-forming bifunctionalization of olefins using molecular iodine and visible light. This strategy did not require any (heavy) metal reagents for double-bond activation because molecular iodine acted as a rare-metal-alternative reagent through visible light irradiation. In addition, the preactivation of amines and other substrates is not required. The mechanistic investigation revealed that the generated iodine radicals under visible light irradiation reacted with alkenes to form a highly reactive intermediate; then, the three-component reaction of diiodide, malonate, and amine furnished iminolactone. Of note, the developed reaction is simple and realized the diversity-oriented synthesis innovative methodology of γ-iminolactone derivatives in drug discovery chemistry.PGL-1 epitope 1 bearing a p-aminoethylphenol group was efficiently synthesized by using linear synthetic routes.  https://www.selleckchem.com/products/r-hts-3.html  A method for efficient synthesis of oligosaccharides containing rhamnose rings was developed. The chemistry is flexible and could be used for the synthesis of other PGLs antigens. A biotinylated PGL-1 antigen 23 was synthesized and could be used as a probe for early detection of leprosy.