Controlled one-pot sequence of three AdE reactions as a novel protocol for the synthesis of polyfunctional compounds

Highly diastereocelective one-pot four-component coupling of p-TolSCI, 1-methoxycycloalkene, methyl vinyl ether and a carbon nucleophile leading to the synthesis of polyfunctional compounds

“…As a rule, in these cases, nearly 1:1 mixtures of diastereomers are formed, and this ratio was found to be only slightly affected by variations in the reaction parameters (the Lewis acid, the temperature, the solvent and the nature of the ArS substituent). 2,3 Here we demonstrate that the utilization of 1-methoxycycloalkenes as VE-I component affects dramatically the stereochemical outcome of the described reaction sequence, and highly stereoselective formation of a single diastereomer can be achieved.…”

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An one-pot TiCl 4 initiated assemblage of polyfunctional compounds via a sequential coupling of p-TolSCl, 1-methoxycycloalkene, methyl vinyl ether and Sn-or Si-capped carbon nucleophile is shown to proceed with high diastereoselectivity at all newly created chiral centres.The sequence of three kinetically independent intermolecular Ad E reactions mediated by sulfur-stabilized reagents and intermediates has been recently developed as a versatile method for the one-pot synthesis of polyfunctional compounds from simple precursors in accordance with Scheme 1. [1][2][3]

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“…The sequence of three kinetically independent intermolecular Ad E reactions mediated by sulfur-stabilized reagents and intermediates has been recently developed as a versatile method for the one-pot synthesis of polyfunctional compounds from simple precursors in accordance with Scheme 1. [1][2][3]…”

2-Trimethylsilyloxyfuran

“…92 The stereochemical outcome of the cycloaddition reaction between TMSOF and N-gulosylnitrone is controlled by the presence of the N-chiral auxiliary on the nitrone, providing a key step during the successful synthesis of the Table 2 TFA or TBAF (38) The 1,3-dimethyloxyallyl cation, generated in situ by treatment of 2,4-dibromo-3-pentenone with copper and sodium iodide, undergoes an endo-selective [4 + 3]-cycloaddition reaction with TMSOF generating a C-1 functionalized 8-oxabicyclo[3.2.1]-6octen-3-one in excellent yield (eq 39). 94a (39) Ring Opening. Oxidation of TMSOF with dimethyldioxirane (DMDO) followed by ring opening of the resulting hydroxybutenolide with a Wittig reagent furnishes exclusively the (2Z, 4E) monoacid product (eq 40).…”

μ-Alkyne dicobalt hexacarbonyl complexes of conjugated enynes as substrates in the arylthio-mediated stepwise AdE reactions

“…1(a),(b),2 Previously, we suggested a novel protocol for the one-pot multicomponent coupling based upon the arylthio-mediated controlled sequence of the intermolecular Ad E reactions, which proceed via the formation of bridged sulfonium ion species as stable intermediates. 3,4 This approach was successfully applied to a number of three-and four-component couplings outlined in Scheme 1 as options A and B, respectively. [3][4][5] The formation of episulfonium ion (ESI) and thiophanium ion (TPI) intermediates in these couplings was well-substantiated by the observed pattern of their reactivity and in several cases was also unequivocally proven by the results of NMR and X-ray studies of the isolated salts.…”