Vinyl and Allylic Sulfones

Grignard reagents convert aromatic sulfonyl chlorides or aromatic sulfonates to sulfones. Aromatic sulfonates have also been converted to sulfones with organolithium compounds.1745 Vinylic and allylic sulfones have been prepared by treatment of sulfonyl chlorides with a vinylic or allylic stannane and a palladium-complex catalyst.1746 Alkynyl sulfones can be prepared by treatment of sulfonyl chlorides with trimethylsilylalkynes, with an AICL catalyst.1747... 

A number of methods for the preparation of vinyl and allyl sulfones are available [1U9, 110], and the syntheses of vinyl sulfones from alkenes has been reviewed [116]. A simple one-step procedure of wide applicability makes use of a palladium-catalysed cross-coupling reaction between aryl and alkyl sulfonyl chlorides and substituted vinyl and allyl stannanes... 

Sulfones. Pd-catalyzed coupling of organostannanes with sulfonyl chlorides provides a direct synthesis of sulfones, particularly vinyl and allyl sulfones. 

Vinyl and allyl sulfonates derived from primary and seeondary alkenols and from propargylie alcohols undergo an RCM in the presence of Ru catalysts to give dihydro 1,2-oxathiane 2,2-dioxides <03SL667>. 

Use of Lithium Naphthalenide. Lithium arene radical anion complexes are mild and highly effective reagents for the reductive desulfonylation process of functionalized sulfones. These reagents have only rarely been used with vinylic and allylic sulfones. In addition to high yields and their operational simplicity, metal arene radical anion complexes demonstrate high chemoselectivity (Eq. 67).123... 

Therefore the bis-sulfone, 2,3-bis(phenylsulfonyl)-l-propene (6), is introduced for the highly selective formation of oxazepines. This bis-sulfone has a three-carbon backbone structure with a vinyl and allylic sulfone, which act in concert to provide unusual reactivity. Bis-sulfone (6), when treated with AT-benzylethanolamine in the presence of triethylamine, gave AT-benzyl-Af-[2-(phenyl-sulfonyl)-2-propyl]ethanolamine (7) in 98% yield, which is then treated with NaOEt causing cycli-zation and formation of oxazepine (8) in 83 /o yield (Scheme 1) <92JOC298>. 

Graphite reacts with alkali metals - potassium, cesium and rubidium - to form lamellar compounds with different stoichiometries. The most widely known intercalate is the potassium-graphite which has the stoichiometry of CgK. In this intercalate the space between the graphite layers is occupied by K atoms. CgK functions as a reducing agent in various reactions such as reduction of double bonds in a,fl-unsaturated ketones [19], carboxylic acids and Schiff bases alkylation of nitriles [20], esters and imines [21] reductive cleavage of carbon-sulfur bonds in vinylic and allylic sulfones [22]. The detailed reaction mechanism of CgK is not known, and the special properties which are ascribed to the intercalate come either from the equilibrium between K+/K [23], or topochemical observations (the layer structure) [24]. 

Synthesis of Vinyl and Allyl Sulfones. In addition to the methods presented above, vinyl and allyl sulfones have been prepared by the palladium-catalyzed cross coupling of vinyl- and allylstannanes with sulfonyl chlorides (eq 30). ... 

Formation of the sterically unfavourable (Z)-alkadienes on dehydrosulfonylation of 7. y-dialkylatcd (C)-allylic sulfones promoted by Bif OK/Bif OH has been attributed to a .wa-cffcct which, by definition, stabilizes the. vyw-conformation required on approach to the transition state.13 The yyw-c fleet of substituents at the (5-position of the (C)-allylic sulfones decreases in the order RO— CH3 — > RS— > — CH2— > (CH3)2CH—> (CH3)3C—> C6H5— and in accord with previous observations of isomerization of (/i)-vinylic to allylic sulfones. 

Presently, many organic additives fall into the category of polymerizable monomers. A non-exhaustive list includes esters (including carboxylic esters/carbonates and other inorganic esters such as phosphates, sulfates, and silicates) that are derived from vinyl and allyl alcohols [2,54,71], vinyl pyridine [63], acrylic acid nitrile [110], maleic acid derivatives [125, 131], vinyl sulfones [128], vinyl silanes [113], and isocyanates [65, 171] (Fig. 2). The synergistic effect of different unsaturated compounds used in various combinations has also been reported [1]. 

Lithiation at C2 can also be the starting point for 2-arylatioii or vinylation. The lithiated indoles can be converted to stannanes or zinc reagents which can undergo Pd-catalysed coupling with aryl, vinyl, benzyl and allyl halides or sulfonates. The mechanism of the coupling reaction involves formation of a disubstituted palladium intermediate by a combination of ligand exchange and oxidative addition. Phosphine catalysts and salts are often important reaction components. 

For trisubstituted olefins, the nucleophile attacks predominantly at the less substituted end of the allyl moiety, e.g. to afford a 78 22 mixture of 13 and 14 (equation 7). Both the oxidative addition of palladium(O) and the subsequent nucleophilic attack occur with inversion of configuration to give the product of net retention7. The synthesis of the sex pheromone 15 of the Monarch butterfly has been accomplished by using bis[bis(l,2-diphenylphosphinoethane)]palladium as a catalyst as outlined in equation 87. A substitution of an allyl sulfone 16 by a stabilized carbon nucleophile, such as an alkynyl or vinyl system, proceeds regioselectively in the presence of a Lewis acid (equation 9)8. The... 

These two products must be formed via an S -type substitution of intermediate 201, which may be formed by the nucleophilic attack of benzenesulfmate with 1,2-pro-padienyl phenyl sulfone. This was further supported by the reaction of 1-methyl-1,2-propadienyl sulfone with bis(phenylsulfonyl)methane in the presence of sodium benzenesulfmate, in which allylic sulfone 202 and vinylic sulfone 203 were formed [103],... 

Inomata, K. Tanaka, Y. Sasaoka, S.-I. Kinoshita, H. Kotake, H. A convenient method for the preparation of a-alkylated vinylic sulfones and their conversion to allylic sulfones. Chem. Lett. 1986, 341—344. 

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