Competing elimination and substitution reactions of simple acyclic disulfides

MP2/aug-cc-pVDZ and B3LYP/cc-pVDZ calculations of the reactions of CH3SSR (R = H or CH3) with fluoride, hydroxide or allyl anion in the gas-phase were performed to determine the mechanism for both elimination and substitution reactions. The elimination reactions were shown to follow the E2 mechanism. The substitution reactions with hydroxide and fluoride proceed by the addition-elimination mechanism, but those with allyl anion proceed by the SN2 mechanism. The elimination reactions with F- and HO- are preferred to the substitution reactions, while allyl anion prefers the substitution route.     

Inter- and intramolecular palladium-catalyzed allyl cross-coupling reactions using allylindium generated in situ from allyl acetates, indium, and indium trichloride

Inter- and intramolecular palladium-catalyzed allyl cross-coupling reactions using allylindium generated in situ by treatment of allyl acetates with indium and indium trichloride in the presence of Pd(0) catalyst and nBuNMe(2) in DMF were successfully demonstrated. Allylindium species generated in situ by reductive transmetalation of pi-allylpalladium(II) complexes, obtained from a variety of allyl acetates in the presence of Pd(0) catalyst together with indium and indium trichloride, were found to be capable of acting as effective nucleophilic coupling partners in Pd-catalyzed cross-coupling reactions. A variety of allyl acetates such as but-1-en-3-yl acetate, crotyl acetate, and 2-methylallyl acetate afforded the corresponding allylic compounds in good yields in cross-coupling reactions. Various electrophilic cross-coupling partners such as aryl iodides and vinyl bromides and triflates participate in these reactions. Not only intermolecular but also intramolecular Pd-catalyzed cross-coupling reactions work equally well to produce the desired allylic coupling products in good yields.     

Addition of organochromium reagents to heteroaryl aldehydes. Synthesis of heteroaryl substituted bis-allyl ethers and homoallyl ethers

Heteroaryl substituted allyl and homoallyl alcohols were synthesised with two different method. Synthesis of bis-allyl ethers and homoallyl ethers were carried out via reaction of allyl bromide with allyl alcohols and homoallyl alcohols, respectively. [2.3]-Wittig Rearrangement reactions of heteroaryl substituted bis-allyl ethers were investigated using GC/MS techniques. In these reactions two unexpected products were isolated in high yield.     

One-pot two-step reaction of selenosulfonate with isocyanides and allyl alcohol under aqueous conditions:Atom-economic synthesis of selenocarbamates and allyl sulfones

In many reactions involving selenosulfonate or thiosulfonate,the sutfone group often leaves in form of benzenesutfinic acid or sodium benzenesulfinate.A one-pot two-step reaction of selenosulfonate with isocyanides and allyl alcohol under aqueous conditions to afford selenocarbamates and allyl sulfone compounds is reported.The sulfinic acid as the first-step side product is converted to the allyl sulfone compound by water promoted reaction with allyl alcohol.Water acts as both an oxygen source of selenocarbamates and as a promoter to drive the second step reactio n.The reactions have the advantages of mild conditions,green,environment-friendly,and high atomic economy.     

Hydrosilylation of Allyl Ethers in the Presence of Platinum(II) Immobilized on Polymethylene Sulfide

Russian Journal of General Chemistry - The reactions of allyl ethyl, allyl butyl, allyl glycidyl, allyl benzyl, and allyl phenyl ethers with 1,1,3,3-tetra-methyldisiloxane in the presence of...     

Novel indium-mediated ternary reactions between indole-3-carboxaldehydes-allyl bromide-enamines: facile synthesis of bisindolyl- and indolyl-heterocyclic alkanes

Indole-3-carboxaldehydes undergo indium-mediated ternary reactions with allyl bromide and indoles to provide symmetrical and unsymmetrical bisindolyl alkanes and with other heterocyclic enamines viz. pyrrole, pyrazole, 6-aminouracil and imidazole to provide indolyl-heterocyclic alkanes in excellent yields. The reactions with substituted allyl bromides proceed with greater ease.     

Organozinc reagents from polyfluoroarenes: Preparation and reactions with allyl halides. Synthesis of allylpolyfluoroarenes

Organozinc compounds of the general formula Ar_FZnX (X = Cl, Ar_F) were synthesized by reactions of Zn with chloropolyfluoroarenes and of Zn/SnCl₂ with polyfluoroarenes. Polyflorinated organozinc compounds reacted with allyl chloride and allyl bromide to give the corresponding allyl-substituted polyfluoroarenes. The reactions with allyl chloride were carried out in the presence of copper(I) salts (CuCl or CuI).     

Combining Spontaneous Polymerization and Click Reactions for the Synthesis of Polymer Brushes: A “Grafting Onto” Approach

Two novel benzofulvene monomers bearing propargyl or allyl groups have been synthesized by means of readily accessible reactions, and were found to polymerize spontaneously by solvent removal, in the apparent absence of catalysts or initiators, to give the corresponding polybenzofulvene derivatives bearing clickable propargyl or allyl moieties. The clickable propargyl and allyl groups were exploited in appropriate click reactions to develop a powerful and versatile “grafting onto” synthetic methodology for obtaining tailored polymer brushes.     

Palladium-catalyzed electrophilic allylation reactions via bis(allyl)palladium complexes and related intermediates

The synthetic scope of the allyl-palladium chemistry can be extended to involve electrophilic reagents. The greatest challenge in these reactions is the catalytic generation of an allyl-palladium intermediate incorporating a nucleophilic allyl moiety. A vast majority of the published reactions that involve palladium-catalyzed allylation of electrophiles proceed via bis(allyl)palladium intermediates. The eta(1)-moiety of the bis(allyl)palladium intermediates reacts with electrophiles, including aldehydes, imines, or Michael acceptors. Recently, catalytic electrophilic allylations via mono-allylpalladium complexes were also presented by employment of so-called "pincer complex" catalysts.     

Scope of the allylation reaction with [RuCp(PP)]+ catalysts: changing the nucleophile or allylic alcohol

The scope of the dehydrative allylation reaction using allyl alcohol as allyl donor with [RuCp(PP)]⁺ complexes as catalysts is explored. Aliphatic alcohols are successfully allylated with allyl alcohol or diallyl ether, obtaining high selectivity for the alkyl allyl ether. The reactivity of aliphatic alcohols is in the order of primary > secondary ? tertiary. The tertiary alcohol 1‐adamantanol reacts extremely slowly in the absence of strong acid, but when HOTs is added, reasonable yields of 1‐adamantyl allyl ether are obtained. The alkyl allyl ether is found to be the thermodynamically favored product over diallyl ether. Apart from alcohols, thiols and indole are also efficiently allylated, while aniline acts as a catalyst inhibitor. Allylation reactions with various substituted allylic alcohols give products with retention of the substitution pattern. It is proposed that a Ru(IV) σ‐allyl species plays a key role in the mechanism of these allylation reactions. Copyright © 2010 John Wiley & Sons, Ltd.     

Acetyl chloride-ethanol brings about a remarkably efficient conversion of allyl acetates into allyl chlorides

AcCl-EtOH transforms primary and secondary allyl acetates into allyl chlorides that retain the olefinic bond in the more stable position. Whereas secondary allyl alcohols also react with almost the same efficacy as the acetates, the reactions of primary allyl alcohols that possess 1,2-disubstituted alkenes are very slow. The products are isolated in high state of purity simply by removal of the volatiles.     

Computational study of the thermal decomposition and the thermochemistry of allyl ethers and allyl sulfides

In spite of the several experimental and computational studies on the thermal decomposition of allyl ethers and allyl sulfides, there are still disagreements on aspects of the reaction mechanism, such as the true nature of the transition states and the grade of synchronicity of the reactions. This work presents a computational study of the gas-phase thermolysis reaction of allyl ethers and allyl sulfides substituted at α-carbon, at the M05-2X/6-31+G(d,p) level of theory and a temperature range from 586.15 to 673.15 K. The substituent groups were methyl, ethyl, n-propyl, i-propyl, allyl, benzyl and acetonyl. It was found that the sulfides react faster than the homologous ethers and that the substituent groups with the capacity of delocalize charge increase the reaction rate. Through natural bond orbital calculations, the transition states were characterized. The synchronicities and atomic charges of the studied reactions were determined. A computational study at the G3 level of theory on the thermochemistry of allyl ethers and sulfides was also carried out.     

The allyl bonded stationary phase. II. Conversions to new phases for gas chromatography

Summary The presence of the double bond on the allyl moiety has been utilized as a site for addition reactions which could produce new stationary phases. Bromination and hydrobromination reactions have been employed to prove the feasibility of making modifications to the allyl bonded phase. Both retention volumes and thermodynamic parameters for the solutes studied change upon conversion to one of the brominated phases. Sample size studies are consistent with a bonded phase adsorption mechanism. FTIR spectra also confirm the modifications which have occurred on the allyl bonded material.     

Influence of allyl ethers in coating resins

The effects of allyl ethers in coating resins have been studied in relations to different systems. The details that have been investigated are: the reactions between allyl ethers-styrene-cobalt salt in air, the influence of cobalt salt on oxidized allyl ethers, and the interaction between allyl ethers and maleic esters with respect to copolymerization. The curing rates of allyl functional oligomers as coatings have also been studied. The results are summarized together with the results from a previous article by the same authors to give an overall view of the curing mechanism in allyl ether functional unsaturated polyester resins dissolved in styrene.     

Iridium‐Catalyzed Allylic Substitutions with Cyclometalated Phosphoramidite Complexes Bearing a Dibenzocyclooctatetraene Ligand: Preparation of (π‐Allyl)Ir Complexes and Computational and NMR Spectroscopic Studies

(π‐Allyl)Ir complexes derived from dibenzocyclooctatetraene and phosphoramidites by cyclometalation are effective catalysts for allylic substitution reactions of linear monosubstituted allylic carbonates. These catalysts provide exceptionally high degrees of regioselectivity and allow the reactions to be run under aerobic conditions. A series of (π‐allyl)Ir complexes were prepared and characterized by X‐ray crystal structure analyses. An allylic amination with aniline displayed different resting states depending on the presence of a strong base. DFT calculations were carried out on the mechanistic aspects of these reactions. The results suggest that for the (π‐allyl)Ir complexes, the formation and reactions with nucleophiles proceed with comparable rates.     

Palladium(0) nanoparticle catalyzed cross-coupling of allyl acetates and aryl and vinyl siloxanes

The cross-coupling of allyl acetates and aryl and vinyl siloxanes proceeds readily by the catalysis of in situ generated palladium(0) nanoparticles. The reactions are stereoselective, and (E)-coupling products are obtained both from cis and trans allyl acetates. The coupling with vinyl siloxanes provides a novel protocol for the synthesis of 1,4-pentadienes.     

Efficient synthetic method of multisubstituted allenes from the reactions of allylindium reagents with 3 degree-propargyl alcohols

An efficient synthetic method of tri- and tetra-substituted allenes having an allyl and methallyl group was developed by the reactions of allylindium reagents generated in situ from indium and allyl bromides with 3 degree-propargyl alcohols.     

Reaction of isocembrol and alcohols on clay

The reactions of isocembrol with allyl and methyl alcohols on K-10 clay were studied.     

Polymerization of allyl(vinyl phenyl) ethers and reactions of the resulting polymers

Solution polymerizations of allyl(o-vinyl phenyl)ether and allyl(p-vinyl phenyl)ether with cationic and radical initiators were investigated. Soluble polymers were formed in polymerizations with boron trifluoride etherate and with benzoyl peroxide. In polymerization with azobisisobutyronitrile the polymerization in dilute solution gave a soluble polymer, whereas that in concentrated solution gave a crosslinked, insoluble one. For informationon the polymerization behavior some infrared and ultraviolet spectroscopic investigations of the soluble polymers were made. From these results it appears that polymers with pendant allyl groups are formed in polymerization with boron trifluoride etherate at low temperature, and polymers containing pendant vinyl groups and allyl groups are obtained with the two types of radical initiator. Copolymerizations of these monomers with ethyl vinyl ether and styrene with the use of boron trifluoride etherate were sucessfully effected. Such reactions as Claisen rearrangement, crosslinking induced with radical initiators, and epoxidation with perbenzoic acid were examined for the polymers prepared in the polymerization with boron trifluoride etherate. Good results were obtained for the former two reactions. However, the latter was unsuccessful.     

Experimental and Computational Studies on Cobalt(I)-Catalyzed Regioselective Allylic Alkylation Reactions

Here, we report the development of cobalt(I)-catalyzed regioselective allylic alkylation reactions of tertiary allyl carbonates with 1,3-dicarbonyl compounds. A family of well-defined tetrahedral cobalt(I) complexes bearing commercially available bidentate bis(phosphine) ligands [(P,P)Co(PPh₃)Cl] are synthesized and explored as catalysts in allylic alkylation reactions. The catalyst [(dppp)Co(PPh₃)Cl] (dppp=1,3-Bis(diphenylphosphino)propane) enables the alkylation of a large variety of tertiary allyl carbonates with high yields and excellent regioselectivity for the branched product. Remarkably, this methodology is selective for the activation of tertiary allyl carbonates even in the presence of secondary allyl carbonates. This contrasts with the selectivity observed in cobalt-catalyzed allylic alkylations enabled by visible light photocatalysis. Mechanistic insights by means of experimental and computational investigations support a Co(I)/Co(III) catalytic cycle.