Gassman’s Cationic [2 + 2] Cycloadditions Using Temporary Tethers

An intermolecular equivalent of Gassman’s cationic [2 + 2] cycloaddition through the use of temporary tethering is described. Notably, hydrazine and hydroxyamide proved to be robust under the acidic conditions required for the cycloaddition, leading to unique cyclobutane manifolds in a highly regio- and stereoselective manner. This development represents a rare usage of hydrazine and hydroxyamide in the capacity as temporary tethers

Catalytic Asymmetric Chlorocyclization of 2‑Vinylphenylcarbamates for Synthesis of 1,4-Dihydro‑2<i>H</i>‑3,1-benzoxazin-2-one Derivatives

A facile synthetic approach to a series of chiral 4-chloromethyl-1,4-dihydro-2<i>H</i>-3,1-benzoxazin-2-one derivatives has been described. This transformation is achieved through the catalytic asymmetric chlorocyclization of 2-vinylphenylcarbamates using a newly developed organocatalyst. Furthermore, the resulting products can be easily converted into diverse bioactive agents

Catalytic Asymmetric Chlorocyclization of 2‑Vinylphenylcarbamates for Synthesis of 1,4-Dihydro‑2<i>H</i>‑3,1-benzoxazin-2-one Derivatives

A facile synthetic approach to a series of chiral 4-chloromethyl-1,4-dihydro-2<i>H</i>-3,1-benzoxazin-2-one derivatives has been described. This transformation is achieved through the catalytic asymmetric chlorocyclization of 2-vinylphenylcarbamates using a newly developed organocatalyst. Furthermore, the resulting products can be easily converted into diverse bioactive agents

Catalytic Asymmetric Chlorocyclization of 2‑Vinylphenylcarbamates for Synthesis of 1,4-Dihydro‑2<i>H</i>‑3,1-benzoxazin-2-one Derivatives

A facile synthetic approach to a series of chiral 4-chloromethyl-1,4-dihydro-2<i>H</i>-3,1-benzoxazin-2-one derivatives has been described. This transformation is achieved through the catalytic asymmetric chlorocyclization of 2-vinylphenylcarbamates using a newly developed organocatalyst. Furthermore, the resulting products can be easily converted into diverse bioactive agents

Arbitrage opportunities and efficiency tests in crypto derivatives

We test the joint efficiency of the bitcoin and ether options and perpetual futures markets and identify the determinants of arbitrage opportunities. Our novel fiat-currency-free put-call parity relationship motivates new arbitrage tests for options-only and option-perpetual cross-markets. Bitcoin and ether derivatives markets are becoming more efficient, especially for options of maturity >= 15 days. Bitcoin derivative markets are generally more efficient than ether derivative markets, but arbitrage strategies can still be highly profitable even under conservative transaction cost scenarios, which include slippage for large orders, especially during periods of high trading volumes or when the blockchain traffic becomes more congested.</p

Arbitrage Opportunities and Efficiency Tests in Crypto Options

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Influence of Albumin Configuration by the Chiral Polymer-Grafted Gold Nanoparticles

The interaction between nanoparticles (NPs) and proteins is a topic of high relevance for the medical application of NPs. This study reveals the molecular chirality on NP surfaces as an indirect regulator of the interaction between proteins and NPs. Poly­(<i>N</i>-acryloyl-valine) (PAV) polymers with d- and l-configurations were conjugated onto gold NPs with a size of 5 nm to obtain the l-PAV-AuNPs and d-PAV-AuNPs, respectively. They had same chemical composition and surface grafting density but different surface chirality. The isothermal titration calorimetry results showed that adsorption of bovine serum albumin onto the l-PAV-AuNPs and d-PAV-AuNPs was primarily driven by electrostatic interaction. Dynamic light scattering, circular dichroism spectroscopy, fluorescence quenching, and isothermal titration calorimetry characterizations revealed that bovine serum albumin molecules adopted both side-on and end-on configurations on the d-PAV-AuNPs, whereas only end-on configuration on the l-PAV-AuNPs

Total Synthesis of (−)-Fusarisetin A and Reassignment of the Absolute Configuration of Its Natural Counterpart

The first total synthesis of (−)-fusarisetin A, the enantiomer of naturally occurring acinar morphogenesis inhibitor (+)-fusarisetin A, was accomplished in 13 steps, leading to the reassignment of the absolute configuration of the natural product. The synthesis featured a Lewis acid-promoted intramolecular Diels–Alder reaction, a Pd-catalyzed O→C allylic rearrangement, a chemoselective Wacker oxidation, and a Dieckmann condensation/hemiketalization cascade

Beyond a Protecting Reagent: DMAP-Catalyzed Cyclization of Boc-Anhydride with 2‑Alkenylanilines

A novel rapid synthesis of quinolines from 2-alkenylanilines has been described; the reaction involves an unexpected DMAP-catalyzed cyclization of 2-alkenylanilines with di-<i>tert</i>-butyl dicarbonate (Boc₂O, 2.0 equiv), and a series of <i>tert</i>-butyl quinolin-2-yl carbonate with various functional groups have been synthesized in good yields under mild conditions. Furthermore, the <i>tert</i>-butyl quinolin-2-yl carbonate can be easily converted into corresponding quinolinones and 2-(pseudo)­haloquinolines

Total Synthesis of (−)-Fusarisetin A and Reassignment of the Absolute Configuration of Its Natural Counterpart

The first total synthesis of (−)-fusarisetin A, the enantiomer of naturally occurring acinar morphogenesis inhibitor (+)-fusarisetin A, was accomplished in 13 steps, leading to the reassignment of the absolute configuration of the natural product. The synthesis featured a Lewis acid-promoted intramolecular Diels–Alder reaction, a Pd-catalyzed O→C allylic rearrangement, a chemoselective Wacker oxidation, and a Dieckmann condensation/hemiketalization cascade