77517-66-9

Upstream product

• 83135-00-6 (hex-1-en-3-yl)methyl carbonate 
• 108-59-8 malonic acid dimethyl ester 
• 18424-76-5 sodiodimethylmalonate 
• 120989-95-9 ethyl (E)-hex-2-en-1-yl carbonate 
• 18424-76-5 dimethyl malonate sodium salt 

Relevant academic research and scientific papers

Allyl 4-Chlorophenyl Sulfone as a Versatile 1,1-Synthon for Sequential α-Alkylation/Cobalt-Catalyzed Allylic Substitution

Despite their unique potential as rare 1,1-dipole synthons, allyl sulfones are rarely used in target-oriented syntheses, likely due to the lack of a general catalytic method for their branch-selective allylic substitution. Herein, we identified allyl 4-chlorophenyl sulfone as a versatile linchpin for both base-mediated α-derivatization and subsequent cobalt-catalyzed allylic substitution. The sequential transformations allow for highly regioselective access to branched allylic substitution products with a variety of aliphatic side chains. The photoredox-enabled cobalt catalysis is indispensable for achieving high yields and regioselectivity for the desulfonylative substitution in contrast to traditional metal-catalyzed protocols, which lead to inferior outcomes in the corresponding transformations.

Ruthenium complexes bearing bulky pentasubstituted cyclopentadienyl ligands and evaluation of [Ru(η5-C5Me4R)(MeCN) 3][PF6] precatalysts in nucleophilic allylic substitution reactions

[Ru(η5-C5Me4R)(MeCN) 3][PF6] (R = CH2 tBu, iPr, tBu, and CF 3; 2-5) complexes were synthesized in two steps starting from the appropriate cyclopentadienes and RuCl3·3H2O. The fully substituted ruthenocenes [Ru(C5Me5)(C 5Me4R*)], [Ru(C5Me5)(C 5nPr4R*)] {R* = (1R,5S)-6,6-dimethylbicyclo- [3.1.1]hept-2-en-2-yl} and [Ru(C5Me5)(C 5nPr5)] were obtained by treating [Ru(C5Me 5)Cl]4 with the corresponding cyclopentadienyllithium salts. Complexes 2-5 were evaluated as catalyst precursors for nucleophilic allylic substitution reactions, and the results were compared to those obtained with the [Ru(C5Me5)(MeCN)3][PF6] (1) precatalyst. The etherification of p-methoxyphenol with the typical aliphatic chlorohexene allylic substrate shows that the introduction of the bulky tert-butyl and trifluoromethyl groups into the tetramethylcyclopentadienyl ring results in a valuable enhancement in regioselectivity in favour of the branched allyl aryl ether. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.

Novel [ruthenium(substituted-tetramethylcyclopentadiene) (2-quinolinecarboxylato)(allyl)] hexafluorophosphate complexes as efficient catalysts for highly regioselective nucleophilic substitution of aliphatic allylic substrates

Stable [ruthenium(R-substituted-tetramethylcyclopentadiene)(2- quinolinecarboxylato) (1-R′-substituted-allyl) hexafluorophosphate (R = Me, R′ = H, Me, n-Pr, Ph; R = t-Bu, R′ = Me) and [ruthenium(pentamethylcyclopentadiene)(2-quinolinecarboxylato)(1-n-propylallyl)] tetrafluoroborate (4′a), as allylruthenium(IV) complexes, have been synthesized in one step, starting from [ruthenium(R-substituted- tetramethylcyclopentadiene)tris(acetonitrile) hexafluorophosphate or tetrafluoroborate complexes, quinaldic acid, and allylic alcohols. Single stereoisomers are obtained and the X-ray single crystal structure determinations of 3b (R = t-Bu, R′ = Me) and 4′a allow one to specify the preferred arrangement. Complexes 3a (R = R′ = Me) and 3b are involved as precatalysts favoring the formation of branched products in regioselective nucleophilic allylic substitution reactions, starting from ethyl 2-(E)-hexen-1-yl carbonate and chlorohexene as unsymmetrical aliphatic allylic substrates. Phenols, dimethyl malonate, and primary (aniline) and secondary (pyrrolidine, piperidine) amines have been used as nucleophiles under mild basic conditions. For the first time, the regioselectivity in favor of the branched product obtained from purely aliphatic allylic substrates is close to the high regioselectivity previously reached starting from cinnamyl-type substrates in the presence of ruthenium catalysts.

Features and applications of [Rh(CO)2Cl]2-catalyzed alkylations of unsymmetrical allylic substrates

(Chemical Equation Presented) A novel regio- and stereoselective [Rh(CO)2Cl]2-catalyzed allylic alkylation of unsymmetrical allylic carbonates was discovered. The regioselectivity of the reaction favors product ratios in which substitution occurs at the carbon bearing the leaving group. When an enantiomerically enriched carbonate (≥99% ee) was examined, the Rh(I)-catalyzed allylic alkylation proceeded stereoselectively to provide the alkylation product with retention of absolute stereochemistry (98% ee). To establish the scope of the [Rh(CO)2Cl]2-catalyzed allylic alkylation, a variety of carbon and heteroatom nucleophiles were examined and the results described. As an application of the Rh(I)-catalyzed allylic alkylation, a series of novel domino reactions have been developed that couple the unique regio- and stereoselective [Rh(CO)2Cl]2- catalyzed alkylation of allylic trifluoroacetates with an intramolecular Pauson-Khand annulation, a cycloisomerization, or a [5+2] cycloaddition. A unique aspect of the method described is the use of a single catalyst to effect sequential transformations in which the catalytic activity is moderated simply by controlling the reaction temperature. Implementation of such processes provides a rapid and efficient entry to a variety of bicyclic carbon skeletons from simple precursors.