Thiopyran 1,1-dioxide derivatives from addition of amines to propargyl sulfone

Abstract

The addition of amines to bis(Ppropyny1) sulfone (3) led to mixtures of 2H-thiopyran 1,l-dioxides, substituted at carbons 3 or 5 with the respective amino residue. Hydrolysis of these cyclic dienamine mixtures afforded a single ketone, viz., 3-methyl-5-oxo-AS-dihydrothiopyran 1,l-dioxide (7). Under appropriate conditions the addition of morpholine to 3 gave the monoadduct 2-N-morpholinyl-1-( 2-propynylsulfony1)propene (9), whereas the addition of dimethylamine yielded the diadduct bis( 2-dimethylamino-1-propenyl) sulfone (8b). Both were readily converted into the respective mixtures of the cyclic dienamines above. A mechanism for the cyclization is discussed. Furthermore, a number of propargylic sulfides, sulfoxides, and sulfones are described. The products from reactions of the sulfones with nucleophilic reagents are recorded.

Multigram Synthesis of Heterabicyclo[n.1.0]alkan‐1‐yl Trifluoroborates

“…4‐(Prop‐2‐yn‐1‐ylsulfonyl)but‐1‐ene (10f): [59] To a solution of 10e (45.4 g, 0.405 mol) in CH 2 Cl 2 (800 mL), MCPBA (140 g, 0.810 mol) was added in portions at 0 °C. The resulting mixture was left stirring at r.t. overnight.…”

A Short Step Conversion of Alkynyl Propargyl Sulfones into Six-Membered Cyclic β-Ketosulfones via an Amine-Induced Novel Ring Closure

“…Natural Product Communications Vol. 13 (5) 2018 597 Si(1)-C( 14)-C(16), 57.0(4); C(12)-Si(1)-C( 14)-C(17), 173.7(3); C(13)-Si(1)-C( 14)-C(15), 179.4(3); C(13)-Si(1)-C( 14)-C(16), -60.2(4); C(13)-Si(1)-C( 14)-C(17), 56.4(4); C(18)-C( 19)-C(20)-C(21), 1.1(6). Crystallographic data have been deposited at the CCDC, 12 Union Road, Cambridge CB2 1EZ, UK, and copies can be obtained on request, free of charge, by quoting the publication citation and the deposition number CCDC 1826547.…”

“…It was easily expected that cyclic -ketosulfones would be formed from alkynyl propargyl sulfones via the ring closure of synthetic equivalents of propargyl -sulfonyl carbanion and the electrondeficient alkynyl sulfone moiety. Actually, the conversion of propargyl sulfones into the corresponding enaminosulfones were reported by Skatteboel [5], and several groups also reported Michael-type nucleophilic addition of alkynyl sulfones forming functionalized vinyl sulfones [6], and our expectation based on these previous reports urged us to a new and convenient synthesis of cyclic -ketosulfones via cyclic enaminosulfones formed through a synchronous amine-induced cyclization of alkynyl propargyl sulfones. Actually, in the course of our synthetic research works on the chemistry of alkynechalcogenolates and their derivatives, we have already found a thermal conversion of alkynyl propargyl sulfones into alleneynes via [3,3] sigmatropic rearrangement and the subsequent SO 2 extrusion from the intermediary allenylthioketene S,S-dioxides [7], and, therefore, the main problem on thermal reaction of alkynyl propargyl sulfones in the presence of amine is the competition of two possible pathways.…”

Cycloadditions and Cyclizations of Acetylenic, Allenic, and Conjugated Dienyl Sulfones

“…Several other types of cyclizations have been reported with bis(allenic) sulfones. These occur via conjugate additions with amines, electrocyclic ring-closures, electrophilic processes, and Pauson−Khand reactions and are treated in sections , , , and , respectively.…”

“…The cyclization of malononitrile with allenic sulfone 2 to afford 367 by a complex cascade of conjugate additions and substitution reactions was described by Lu and Lu . The bis(allenic) sulfone 273 , generated in situ from the corresponding bis(propargyl) isomer 272 , reacted with morpholine and other secondary amines to produce a mixture of double bond isomers 368a and 368b . Presumably, the initial conjugate addition of the amine to one allenic sulfone moiety formed a sulfone-stabilized allyl anion, which then added to the remaining allenic sulfone (Scheme ).…”