Synthesis of New Heterocyclic Compounds by Reaction of Sodium Sulfide, Sodium Selenide, or Methylamine with the Sulfoxides and Sulfones Prepared from 1-Vinylthio-1-alkynes

Alkynylthioimidazolium Salts: Efficient Reagents for the Synthesis of Alkynyl Sulfides by Electrophilic Thioalkynylation

“…Following standard oxidation procedures, 17 could be selectively transformed either into sulfoxide 33 or sulphonylacetylene 34 . This last compound is an efficient double Michael acceptor and reacts with butyl amine or Na 2 S to afford dihydrothiazine or dihydrodithiine derivatives 35 and 36 , respectively . Thiophene 37 was also obtained from 17 after extensive heating in the presence of Na 2 S. Further studies are still necessary to determine the complete mechanistic pathway of this transformation; however, the substitution pattern in 37 supports a mechanism in which migration of a propenyl cation between the two sulphur centers occurs after a first hydrothiolation of the C≡C triple bond.…”

“…Illustrative examples are described in Scheme 6, taking 17 and 21 as model substrates. [15] Thiophene 37 was also obtained from 17 after extensive heatingi nt he presence of Na 2 S. Further studies are still Anisotropic displacementp arameters hownat5 0% probability leveland hydrogen atoms omitted for clarity. [14] This last compound is an efficient double Michael acceptora nd reacts with butyl amine or Na 2 St oa fford dihydrothiazine or dihydrodithiine derivatives 35 and 36,r espectively.…”

“…groups,w hich suffer the nucleophilic attack at the sp-hybridized carbon directly bonded to sulphur. [8] The robustness and applicabilityo ft he protocol we developed is highlighted especially by the successful preparation of an umber of structurally differentiated thioacetylenes containing alkyl (4)(5)(6)(7)(8)(9), aryl (10)(11)(12)(13)(14), vinyl (15)(16)(17)(18)(19), or even second alkynyl units (20-23)d irectly attached to the central sulfur atom (Scheme 3). The preparation of the last two groups of products is remarkable because their synthesis is challenging through other routes.…”

“…[14] This last compound is an efficient double Michael acceptora nd reacts with butyl amine or Na 2 St oa fford dihydrothiazine or dihydrodithiine derivatives 35 and 36,r espectively. [15] Thiophene 37 was also obtained from 17 after extensive heatingi nt he presence of Na 2 S. Further studies are still Scheme4.Synthesis of alkynylseleno imidazolium salts. Reagents and conditions (yields): a) Br 2 ,CH 2 Cl 2 ,08C!RT;(68 %);b )RZnBr,T HF, À78 8C!RT,and then NaSbF 6 ; 26 a (98 %); 26 b,(94 %); 26 c (58 %).…”

Propargylic Sulfides: Synthesis, Properties, and Application

“…Doubly conjugated addition of amines to bifunctional acetylenic sulfones such as 199 took place to afford the cyclic product 200 . Also, chiral cyclic amine 202 was formed by double Michael additions of (−)-ephedrine to propargyl sulfone 201 or to the corresponding allenyl and 1-propynyl derivatives (Scheme )…”