In this work, five novel A-π-D-π-A type molecules D1-D5 were designed by adding unusual benzothiadiazole derivatives as π-spacer blocks to the efficient reference molecule DRCN5T for application donor materials in organic solar cells (OSCs). Based on a density functional theory approach, comprehensive theoretical study was performed with different functionals (B3LYP, B3LYP-GD3, B3LYP-GD3BJ, CAM-B3LYP, M06, M062X, and wB97XD) solvent types (PCM SMD) at extended basis set 6-311+g(d,p) evaluate...

N-benzyl aspartate nitrones 2, prepared by addition of N-benzylhydroxylamine to dialkyl acetylenedicarboxylates 1, underwent [3 + 2] thermal cycloaddition with a wide range alkenes afford isoxazolidines 4 bearing polyfunctionalized quaternary center. Under these uncatalyzed conditions, the trans stereocontrol observed vinyl ethers is higher than that obtained all acyclic activated reported date. The first asymmetric access type-4 pure adduct was achieved starting from chiral nitrone derived...

Amino acid derived nitrones were conveniently synthesized in good-to-excellent yields by condensation of α-ketoesters with N-benzylhydroxylamine. The cycloaddition reactions these different alkenes investigated under thermal solvent-free conditions. Considering conversions, yields, and selectivities, alkyl vinyl ethers have proven to be valuable partners achieve this transformation, which creates a tetrafunctionalized stereogenic quaternary center. From the adducts from ethers, three-step...

An improvement in the catalytic enantioselective allylboration of isatins with 2-allyl-1,3,2-dioxaborolane presence chiral BINOL derivatives is reported, offering an efficient one-step access to enantioenriched N-unprotected 3-allyl-3-hydroxy-2-oxindoles. This process also effective for crotylboration reaction enantiomeric ratios (er) up 97:3, as well asymmetric synthesis homopropargylic alcohols via allenyl addition indoline-2,3-diones. Origins high enantioselectivity BINOL-catalyzed were...

Chiral enamides, easily prepared in one step from a cyclic ketone and an oxazolidinone, are successfully employed high-yielding, endo, facially selective Hetero-Diels-Alder reactions involving activated oxadienes Siever's reagent as catalyst. From the resulting bicyclic heteroadducts, novel efficient asymmetric modification for Robinson annulation of monoketones is described.

Cycloaddition reactions occupy a special place in organic synthesis because of the simultaneous creation several bonds and generation new stereogenic centers often highly stereocontrolled ...

A catalytic 1,3-dipolar cycloaddition between carboalkoxy ketonitrones and methacrolein under the effect of chiral ruthenium Lewis acid (R,R-1) was developed with high regio-, diastereo-, enantiocontrol. The diastereochemical outcome reaction is marked by a significant solvent effect, divergent endo or exo control can be tuned an appropriate choice both N- O-substituents ketonitrone. rationale based on computational study interactions methacrolein-Ru complex its counteranion (SbF6(-)),...

Original acyclic (E)-α,α-dialkylketonitrones bearing a chiral auxiliary on their nitrogen atom were synthesized and successfully employed for the asymmetric synthesis of α,α-disubstituted amino acids using regio- stereocontrolled 1,3-dipolar cycloaddition reactions with vinyl ethers. N-Glycosyl auxiliaries found to provide excellent exo- π-facial stereocontrol. The obtained enantiopure cycloadducts selectively transformed into functional related β-peptides through highly regioselective...

New isoxazolidines were synthesized in good to excellent yields by 1,3-dipolar cycloaddition of N-vinylamide dipolarophiles and nitrones. Strikingly, solvent-free conditions gave high conversion yields, shortened reaction time, minimized degradation products. N-Vinyloxazolidin-2-one its analogues used these reactions conveniently prepared a modified version Buchwald's one-step copper-catalyzed vinylation using vinyl bromide. From the adducts, two-step access various unsymmetric aspartate...

1,3-dipolar cycloadditions (1,3-DC) reactions involving nitrones as dipole have met a recent growing interest 1 – 8 especially in their diastereoselective and enantioselective versions. 9 - 10 This...

Abstract A stereospecific Mizoroki–Heck cross‐coupling of differently substituted glycals with haloarenes resulting in the exclusive formation either α‐ or β‐aryl‐ C ‐glycosides depending solely on configuration at C3 was achieved. The reaction easy to set up because no specific precautions were required concerning moisture oxygen, and it proceeded by a chirality transfer from C1. After optimization conditions, various prepared (7 examples) arenes (10 tested, leading stereospecifically...

Abstract New ionic‐liquid‐supported tin reagents were synthesized and used in Stille cross‐coupling reactions. High yields of biaryls obtained under low‐temperature, solvent‐free, ligand‐free conditions, with simple purification techniques. Moreover, the compound could be recycled up to five times without significant loss reactivity. An expanded catalytic cycle for cross coupling reaction is proposed order explain side products that formed certain conditions.(© Wiley‐VCH Verlag GmbH &...

Abstract This paper describes the synthesis of both polysubstituted oxazolo‐pyrrolidinones and ‐piperidinones by a domino process. The methodology is based on reaction between hydroxyl halogenoamides Michael acceptors, which leads efficiently to bicyclic lactams. process compatible with unsymmetrical electron‐withdrawing groups acceptor, allows formation two contiguous fully controlled tertiary quaternary stereocenters. In case tetrasubstituted adjacent stereocenters are formed in good...

An original and rapid domino reaction for access to oxazolidin-4-ones is presented. Simply by heating α-bromoamido alcohol in the presence of KNaCO3 water with readily prepared Michael acceptors, an unprecedented molecular rearrangement generated. This new methodology enables hitherto unreported synthesis functionalized oxazolidin-4-ones. The process was proved be compatible a wide variety substrates, high regioselectivities were achieved.

A totally new acid-free domino process to access highly functionalized bicyclic γ- and δ-lactams starting from commercially available inexpensive ethoxymethylene derivatives is reported. Mechanisms elucidated by computational calculations led reaction conditions that boosted the yields up 3.5 times higher.

The [4+2] heterocycloaddition reaction between (E)-γ-substituted β-unsaturated α-oxo esters 1a−d and cyclic acyclic ketone enol ethers 2a−l afforded heteroadducts 3−5 in high yields when either [Eu(fod)3] or SnCl4 were used as the catalyst. With methyl (E)-benzylidenepyruvate (1a), two catalytic modes displayed divergent stereoselectivities. In case of silyl ether 2h, X-ray investigations established relative configurations bicyclic adducts 3h 5h, each obtained major isomer with SnCl4,...

The access to new oxazolo[3,2-d][1,4]oxazepin-5(3H)-ones starting from α-bromoamido alcohols and Michael acceptors under mild conditions is presented. This domino process proved be chemo-, regio-, stereoselective allows the formation of a large diversity highly functional 7-membered rings in good yields up 95%. complete shift regioselectivity intermediate enolate C–C C–O bond formation, contrary already known alkylations such ambident nucleophiles, mostly triggered by steric effects. last...

The exploration of the composition space diagram FeF3/ZnF2–Hamtetraz-HFaq system (Hamtetraz = 5-aminotetrazole) by solvothermal synthesis at 160 °C for 72 h in dimethylformamide (DMF) has evidenced five new hybrid fluorides (1–5); structures are characterized from single crystal X-ray diffraction data. [Hdma]·(ZnFeIII(H2O)4F6) (1) and [Hdma]·[Hgua]2·(FeIIIF6) (2) contain anionic inorganic chains or isolated octahedra weakly hydrogen bonded (Class I hybrids) to dimethylammonium (Hdma) and/or...

UV irradiation leads to the degradation of PS or PE nanoplastics dispersed in water. They initially become porous, then fragment and finally degrade completely.

The first de novo synthesis of a beta-C-naphthyl glycoside displaying convenient functionality for subsequent transformations into complex C-aryl glycosides is reported. this (+/-)-beta-C-1,5-dibenzyloxynaphthyl 6,6,6-trifluoro-3-amino relies on hyperbaric HDA reaction involving new 2-vinylnaphthalenic dienophile.

Highly diastereo‐ and enantioselective 1,3‐dipolar cycloadditions between functional ketonitrones β‐substituted enals are promoted by MacMillan imidazolidinium organocatalysts. A study of the reaction scope shows that high selectivities conserved if N‐protecting group or ester function is varied. However, sensitive to steric interactions with C substituent nitrone. In all cases, proceeds exo selectivity. most a third diastereomer, incompatible concerted mechanism, was also observed, albeit...

Abstract Eu(fod) 3 ‐catalyzed heterocycloaddition of chiral β‐alkyl‐ N ‐vinyl‐1,3‐oxazolidin‐2‐ones with a heterodiene bearing lipidic chain led to heterocycloadducts in high yield excellent endo and facial selectivities. An original lactone, potent precursor ceramide analog, was obtained seven steps from the adduct convergent manner after appropriate functionalization.