New Synthetic Approaches to Symmetrical Sulfur-Bridged Carbocycles (original) (raw)

Synthesis and structure of novel sulfur bridged cyclic di- and tetraalkynes

Tetrahedron Letters

Some novel sulfur bridged 13-to 30-membered cyclic di-and tetraalkynes derived from 1,2-, 1,3-and 1,4-dihydroxybenzene and 1,2-bis(bromomethyl)benzene were synthesized and their structures confirmed by X-ray analysis. The unexpected formation of 2,6-divinyl-1,4-dithiin during Na 2 S/alumina induced cyclization was also observed and the reaction mechanism is discussed.

Reactions of (phenylethynyl)sulfones with tricyclo[4.1.0.0 2,7 ]heptanes

Canadian Journal of Chemistry, 2013

Methyl-, phenyl-, p-chlorophenyl-, and p-tolyl(phenylethynyl)sulfones under photochemical or thermal initiation add to the central bicyclobutane C1–C7 bond of 1-R(H, Me, Ph)-tricyclo[4.1.0.02,7]heptanes anti-selectively, and form norpinic adducts containing a phenylethynyl group in a geminal to substituent R position, and an endo-oriented sulfonyl group in position 7. The corresponding ketones were prepared by the hydration of the anti-adducts by the method of Kucherov. The ketone with a methylsulfonyl substituent under reflux in toluene in the presence of KOH powder and the phase-transfer catalyst (TEBA-Cl) afforded the tricyclic sulfone.

Sulfones in heterocyclic synthesis: advances in the chemistry of phenyl sulfonylacetophenone

Research on Chemical Intermediates, 2017

The present review provides a survey on the structural features, synthetic methodologies, and reactions of phenyl sulfonylacetophenone, considered to be one of the most important synthons in the field of synthetic organic chemistry. b-Ketosulfone is an active C-H acid which has been widely used as a nucleophile in many organic transformations. It has been used for synthesis of five-and sixmembered ring systems containing one or two heteroatoms. In addition, it has been used as a starting material for synthesis of fused heterocycles, cyclopropane, cyclopentene, and cyclohexanone derivatives. b-Ketosulfone has been used for synthesis of cand d-ketosulfones, 1,4-diketones, amides, ethers, and substituted benzene derivatives due to its high synthetic importance. It is a reactive intermediate in electrophilic reactions such as halogenation, alkylation, arylation, heteroarylation, and coupling reactions, and is involved in other types of reaction such as Diels-Alder condensation with aldehydes and desulfonylation. The mechanistic pathways of these reactions and their important synthetic applications are discussed herein.

New Organic Chemistry of Sulfur Dioxide

2007

Simple 1,3-dienes undergo highly stereoselective hetero-Diels-Alder additions with SO 2 at low temperature giving sultines. These reactions that are faster than the more exothermic cheletropic additions of SO 2 -producing sulfolenes. This has led to the invention of a new C-C bond-forming reaction combining electron-rich dienes and alkenes with SO 2 . The reaction cascade has been exploited to develop combinatorial, one-pot, four-component syntheses of polyfunctional sulfones, sulfonamides, and sulfonic esters. It also allows us to generate, in one-pot operations, enantiomerically enriched polypropionate fragments containing up to three contiguous stereogenic centers and a (E)-alkene unit. These fragments can be used directly in further C-C bond-forming reactions, such as cross-aldol condensations, thus permitting the expeditious construction of complicated natural products of biological interest (e.g., Baconipyrones, Rifamycin S, Apoptolidinone) and analogues. New ene reactions of SO 2 have also been discovered; they open new avenues to organic synthesis.

Stereospecific cyclodehydration of 1,4-sulfanylalcohols to thiolanes: mechanistic insights

Tetrahedron, 2008

A series of thiolanes were prepared by cyclodehydration of sulfanylalcohols in the presence of catalytic amounts of p-toluenesulfonic acid or by using K10 clay. The sulfur heterocycles were synthesised in good to excellent yields using either a conventional Dean-Stark method or microwave irradiation under solvent-free conditions. The reaction could be performed regio-and stereoselectively and its mechanism was investigated by means of enantio-and diastereomerically enriched substrates. In contrast to previous studies, our results are consistent with an intramolecular S N 2-type mechanism as a general pathway.