7530-13-4Relevant articles and documents
Arylsulfonate esters in solid phase organic synthesis. I. Cleavage with amines, thiolate, and imidazole
Rueter, Jaimie K.,Nortey, Samuel O.,Baxter, Ellen W.,Leo, Gregory C.,Reitz, Allen B.
, p. 975 - 978 (1998)
The arylsulfonate ester functionality connecting an alkyl chain to a polystyrene resin is cleaved with neat volatile primary or secondary amines to give secondary or tertiary amines, respectively, in high yields and purity. Non-volatile secondary amines, thiols, and imidazole also cleave the alkyl chain efficiently to afford the expected products which can be readily purified by an ion-exchange resin work-up method.
Ambient Moisture Accelerates Hydroamination Reactions of Vinylarenes with Alkali-Metal Amides under Air
Bole, Leonie J.,Davin, Laia,García-álvarez, Joaquín,Hernán-Gómez, Alberto,Hevia, Eva,Kennedy, Alan,Mulks, Florian F.
supporting information, p. 19021 - 19026 (2020/09/01)
A straightforward alkali-metal-mediated hydroamination of styrenes using biorenewable 2-methyltetrahydrofuran as a solvent is reported. Refuting the conventional wisdom of the incompatibility of organolithium reagents with air and moisture, shown here is that the presence of moisture is key in favoring formation of the target phenethylamines over competing olefin polymerization products. The method is also compatible with sodium amides, with the latter showing excellent promise as highly efficient catalysts under inert atmosphere conditions.
Heavier alkaline earth catalysts for the intermolecular hydroamination of vinylarenes, dienes, and alkynes
Brinkmann, Christine,Barrett, Anthony G. M.,Hill, Michael S.,Procopiou, Panayiotis A.
supporting information; experimental part, p. 2193 - 2207 (2012/03/10)
The heavier group 2 complexes [M{N(SiMe3)2} 2]2(1, M = Ca; 2, M = Sr) and [M{CH(SiMe3) 2}2(THF)2] (3, M = Ca; 4, M = Sr) are shown to be effective precatalysts for the intermolecular hydroamination of vinyl arenes and dienes under mild conditions. Initial studies revealed that the amide precatalysts, 1 and 2, while compromised in terms of absolute activity by a tendency toward transaminative behavior, offer greater stability toward polymerization/oligomerization side reactions. In every case the strontium species, 2 and 4, were found to outperform their calcium congeners. Reactions of piperidine with para-substituted styrenes are indicative of rate-determining alkene insertion in the catalytic cycle while the ease of addition of secondary cyclic amines was found to be dependent on ring size and reasoned to be a consequence of varying amine nucleophilicity. Hydroamination of conjugated dienes yielded isomeric products via η3-allyl intermediates and their relative distributions were explained through stereoelectronic considerations. The ability to carry out the hydroamination of internal alkynes was found to be dramatically dependent upon the identity of the alkyne substituents while reactions employing terminal alkynes resulted in the precipitation of insoluble and unreactive group 2 acetylides. The rate law for styrene hydroamination with piperidine catalyzed by [Sr{N(SiMe3) 2}2]2 was deduced to be first order in [amine] and [alkene] and second order in [catalyst], while large kinetic isotope effects and group 2 element-dependent ΔS? values implicated the formation of an amine-assisted rate-determining alkene insertion transition state in which there is a considerable entropic advantage associated with use of the larger strontium center.
