Bicyclic allyltin derivatives through selective “one pot” hydrostannation - Diels-Alder reaction

Abstract

in recognition of their achievements in organic chemistry and their contributions in the development of the field in our country AbstractIn this paper we report a simple "one pot" procedure to functionalized allyltin derivatives from 1-ethynylcyclohexene. Radical addition of trineophyltin hydride gives quantitatively to (Z,E)-1-(2-trineophylstannylvinyl)cyclohexene, a conjugated dienyl-stannane that, via a [4+2] cycloaddition reaction (Diels-Alder) with activated dienophiles, affords substituted bicyclic unsaturated products with specific stereochemistry and a trialkylstannyl group in allylic position. The Stille reaction of the allyltin compound enables the synthesis of aryl substituted bicyclic compounds in moderate to good yields (48-85%).

Efficient asymmetric TADDOLs-organocatalyzed cycloaddition for the synthesis of allyltin derivatives

“…It has been demonstrated that a great number of Lewis acids have been used to promote Diels-Alder reactions with excellent enantioselectivity [15]. In previous work [11] we studied the synthesis of a variety of functionalized allyltin derivatives in high yields through a "one pot" hydrostannation-Diels-Alder reaction as precursors of analogs of non-steroidal compounds acting as selective receptor modulators in the treatment of pathologies such as obesity, diabetes and inflammatory processes. The regio-and stereochemistry of the proposed structures were defined through a detailed spectroscopic analysis and molecular modeling.…”

“…In previous studies [11], we obtained 4-trineophylstannylbicyclo [4.4.0]dec-5-en-3-yl cyanide (10) and methyl-2-methyl-4trineophylstannylbicyclo[4.4.0]dec-5-ene-2-carboxilate (11) products as enriched mixtures of the "meta" adducts that were unable to separate from the ortho isomers (10′ and 11′). Now, and for our great satisfaction, dienophile 5 gave only one product 10 in the cycloaddition reaction when catalyst II was employed under methods A and B, and methyl-2methylacrylate ( 6) yielded adduct 11 as the only product with catalyst II under method C conditions, although in low yields in both cases.…”

“…Chemical shifts (δ) are reported in ppm and coupling constants (J) are in Hz. Compounds described in this work (7)(8)(9)(10)(11) were characterized by comparing their 1 H, 13 C and 119 Sn NMR spectra to the previously reported data [11]. The progress of the reaction and the purity of compounds were monitored by TLC analytical silica gel plates (Merck 60 F254).…”

“…d Starting material. e Structure characterization in reference[11]. f From 119 Sn NMR spectra of the reaction crude product.…”