The economic system of society: improving the efficiency of bank supervision and regulation

У статті розглядаються основні аспекти організації банківського нагляду в системі Національного банку України для формування стійкого фінансового механізму функціонування банківської системи.The basic aspects of bank supervision organization in the system of the National bank of Ukraine for forming of proof financial mechanism of the banking system functioning are examined in the article

Direct and Highly Enantioselective Iso-Pictet–Spengler Reactions with α-Ketoamides: Access to Underexplored Indole Core Structures

Direct, one-pot, operationally simple, and highly enantioselective iso-Pictet–Spengler reactions are reported. The reactions involve the condensation of either (1<i>H</i>-indol-4-yl)methanamine or 2-(1<i>H</i>-Indol-1-yl)ethanamine with a variety of α-ketoamides, followed by the addition of a simple and commercially available chiral silicon Lewis acid. These reactions are the first asymmetric examples of these cyclization modes and provide access to 3,3-disubstituted-1,3,4,5-tetrahydropyrrolo[4,3,2-<i>de</i>]isoquinolines and 1,1-disubstituted-1,2,3,4-tetrahydropyrazino[1,2-<i>a</i>]indoles, respectively, two relatively underexplored indole-based core structure motifs in medicinal chemistry

A Highly Stereoselective, Efficient, and Scalable Synthesis of the C(1)–C(9) Fragment of the Epothilones

A second-generation synthesis of the C(1)–C(9) fragment of the epothilones is reported. The key tandem intramolecular silylformylation/crotylsilylation/“aprotic” Tamao oxidation sequence has been redeveloped as a stepwise intermolecular variant, allowing excellent levels of diastereoselectivity in the crotylation step and proceeds in 50% overall yield on gram scale. An improved synthesis of the homopropargyl alcohol starting material is also described, which proceeds in four steps and >99% ee from inexpensive starting materials and is amenable to multigram scales

Beyond the Roche Ester: A New Approach to Polypropionate Stereotriad Synthesis

An efficient, step-economical, and scalable approach to the synthesis of polypropionate stereotriads has been developed. Either 2-butyne or propyne is subjected to rhodium-catalyzed silylformylation and in situ crotylation of the resulting aldehydes. Tamao oxidation under either “standard” conditions or “aprotic” conditions then delivers the completed stereotriads in a three-step, two-pot sequence. In contrast to the classical Roche ester approach, the α-stereocenter is obtained for “free.

A “Methyl Extension” Strategy for Polyketide Natural Product Linker Site Validation and Its Application to Dictyostatin

An approach to the validation of linker strategies for polyketide natural products with few or no obvious handles for linker attachment, and its application to dictyostatin, are described. Analogues in which the C(6)- and C(12)-methyl groups were replaced by 4-azidobutyl groups were prepared and shown to retain the low nanomolar potency of dictyostatin. Further, conjugation of the C(6) analogue with a cyclooctyne resulted in only minor attenuations in potency. Together, these results shed light on the binding of dictyostatin to β-tubulin, establish a validated linker strategy for dictyostatin, and set the stage for the synthesis and study of dictyostatin conjugates

Exploiting Pseudo <i>C</i>₂‑Symmetry for an Efficient Synthesis of the F‑Ring of the Spongistatins

A concise and efficient synthesis of the F-ring fragment of the potent antimitotic marine macrolide spongistatin 1 has been developed. The key sequence involves double cross-metathesis/Sharpless asymmetric dihydroxylation reactions to establish four stereocenters in a pseudo <i>C</i>₂-symmetric array, followed by a selective protection reaction that breaks the pseudosymmetry, establishes a fifth stereocenter, and effectively differentiates the ester termini. Overall, the six contiguous stereocenters in the C(37)–C(45) F-ring fragment are established in just seven steps

Exploiting Pseudo <i>C</i>₂‑Symmetry for an Efficient Synthesis of the F‑Ring of the Spongistatins

A concise and efficient synthesis of the F-ring fragment of the potent antimitotic marine macrolide spongistatin 1 has been developed. The key sequence involves double cross-metathesis/Sharpless asymmetric dihydroxylation reactions to establish four stereocenters in a pseudo <i>C</i>₂-symmetric array, followed by a selective protection reaction that breaks the pseudosymmetry, establishes a fifth stereocenter, and effectively differentiates the ester termini. Overall, the six contiguous stereocenters in the C(37)–C(45) F-ring fragment are established in just seven steps

Evolution of an Efficient and Scalable Nine-Step (Longest Linear Sequence) Synthesis of Zincophorin Methyl Ester

Because of both their synthetically challenging and stereochemically complex structures and their wide range of often clinically relevant biological activities, nonaromatic polyketide natural products have for decades attracted an enormous amount of attention from synthetic chemists and played an important role in the development of modern asymmetric synthesis. Often, such compounds are not available in quantity from natural sources, rendering analogue synthesis and drug development efforts extremely resource-intensive and time-consuming. In this arena, the quest for ever more step-economical and efficient methods and strategies, useful and important goals in their own right, takes on added importance, and the most useful syntheses will combine high levels of step-economy with efficiency and scalability. The nonaromatic polyketide natural product zincophorin methyl ester has attracted significant attention from synthetic chemists due primarily to the historically synthetically challenging C(8)–C(12) all-<i>anti</i> stereopentad. While great progress has been made in the development of new methodologies to more directly address this problem and as a result in the development of more highly step-economical syntheses, a synthesis that combines high levels of step economy with high levels of efficiency and scalability has remained elusive. To address this problem, we have devised a new synthesis of zincophorin methyl ester that proceeds in just nine steps in the longest linear sequence and proceeds in 10% overall yield. Additionally, the scalability and practicability of the route have been demonstrated by performing all of the steps on a meaningful scale. This synthesis thus represents by a significant margin the most step-economical, efficient, and practicable synthesis of this stereochemically complex natural product reported to date, and is well suited to facilitate the synthesis of analogues and medicinal chemistry development efforts in a time- and resource-efficient manner

High-Conductance Pathways in Ring-Strained Disilanes by Way of Direct σ‑Si–Si to Au Coordination

A highly conducting electronic contact between a strained disilane and Au is demonstrated through scanning tunneling microscope-based single-molecule measurements. Conformationally locked <i>cis</i> diastereomers of bis­(sulfide)-anchor-equipped 1,2-disilaacenaphthenes readily form high-conducting junctions in which the two sulfide anchors bind in a bipodal fashion to one gold electrode, providing enough stability for a stable electrical contact between the Si–Si σ bond and the other electrode

Synthesis and Evaluation of a Linkable Functional Group-Equipped Analogue of the Epothilones

An approach to the validation of a linker strategy for the epothilone family of microtubule-stabilizing agents is reported. An analogue of epothilone B in which the C(6) methyl group has been replaced with a 4-azidobutyl group has been prepared by total chemical synthesis, and amides derived from the azido group have been shown to retain the activity of the parent compound. These results set the stage for an evaluation of the potential of the epothilones to serve as the drug component of antibody–drug conjugates and other selective tumor cell-targeting conjugates