26900-57-2Relevant academic research and scientific papers
Mechanistic studies on the SCS-pincer palladium(II)-catalyzed tandem stannylation/electrophilic allylic substitution of allyl chlorides with hexamethylditin and benzaldehydes
Pijnenburg, Niels J. M.,Cabon, Yves H. M.,Van Koten, Gerard,Klein Gebbink, Robertus J. M.
, p. 4858 - 4868 (2013/05/23)
This paper describes a mechanistic study of the SCS-pincer Pd II-catalyzed auto-tandem reaction consisting of the stannylation of cinnamyl chloride with hexamethylditin, followed by an electrophilic allylic substitution of the primary tandem-reaction product with 4-nitrobenzaldehyde to yield homoallylic alcohols as the secondary tandem products. As it turned out, the anticipated stannylation product, cinnamyl trimethylstannane, is not a substrate for the second part of the tandem reaction. These studies have provided insight in the catalytic behavior of SCS-pincer PdII complexes in the auto-tandem reaction and on the formation and possible involvement of Pd0 species during prolonged reaction times. This has led to optimized reaction conditions in which the overall tandem reaction proceeds through SCS-pincer PdII-mediated catalysis, that is, true auto-tandem catalysis. Accordingly, this study has provided the appropriate reaction conditions that allow the pincer catalysts to be recycled and reused. Minor isomer, major importance: A mechanistic study of the SCS-pincer Pd-catalyzed auto-tandem reaction is described consisting of the stannylation of cinnamyl chloride, followed by an electrophilic allylic substitution of the primary tandem reaction product to yield homoallylic alcohols (see scheme; SCS=[2,6-(CH2SPh)2C6H3] -). This study pointed out that the anticipated stannylation product, cinnamyl trimethylstannane, is not a substrate for the second part of the tandem reaction. Copyright
SCS-pincer palladium-catalyzed auto-tandem catalysis using dendritic catalysts in semi-permeable compartments
Pijnenburg, Niels J.M.,Dijkstra, Harm P.,Van Koten, Gerard,Gebbink, Robertus J. M. Klein
, p. 8896 - 8905 (2011/10/12)
Novel monometallic and dendritic SCS-pincer palladium complexes 2, 3 and 4 have been synthesized in good yields (60-89%) and high purity (palladium loading >97%). These complexes were successfully used as catalysts in the stannylation of cinnamyl chloride
Photochemical 1,3-stannyl rearrangement of allylic stannanes
Takuwa, Akio,Kanaue, Takashi,Yamashita, Koichi,Nishigaichi, Yutaka
, p. 1309 - 1314 (2007/10/03)
The photochemical 1,3-stannyl rearrangement of allylic stannanes has been investigated. The photorearrangement of (E)-cinnamyl(triphenyl)stannane is not observed in benzene under anaerobic conditions, while the photoinduced 1,3-stannyl migration takes place in the same solvent under aerobic conditions, or in the presence of organic halides or a radical-trapping agent to give a photoequllibrium mixture of the cinnamylstannane and its branched regioisomer, 1-phenylprop-2-enyl(triphenyl)stannane, with the latter predominating. Cinnamyl(trialkyl)stannanes and their homologues also afford the corresponding branched allylstannanes under similar photochemical conditions. These 1,3-stannyl migrations proceed intramolecularly via cinnamyl π-π* excitation in competition with homolytic (cinnamyl)C-Sn bond fission. In contrast, the 1,3-stannyl migration of crotyl- and prenyl-(tributyl)-stannanes is not efficient, but their triphenyl or dibutylphenyl derivatives undergo the 1,3-rearrangement via excitation of the phenyl group(s) on the tin atom to give a regioisomeric mixture of the starting linear tin compounds and the branched ones with the former predominating.
REACTIONS OF TRIMETHYLTINSODIUM WITH ALKYL HALIDES. EFFECTS OF STRUCTURE AND SOLVENT ON COURSE OF REACTION AND REACTIVITY
Kuivila, Henry G.,Reeves, William G.
, p. 801 - 808 (2007/10/02)
The reactions of eleven alkyl chlorides and bromides with trimethyltinsodium have been examined.It has been found that primary and secondary halides react smoothly and rapidly to provide good yields of substitution products in THF and TG at Oo.The reaction is less satisfactory for allyl bromide and unsatisfactory for cinnamyl chloride and tertiary halides.Trimethyltinsodium and 2-chlorobutane react with second order kinetics.Relative reactivities of the halides have been determined in the two solvents and are discussed.Lithium, sodium and potassium as counterions yielded the same results in the reaction of the trimethyltinalkils with primary, secondary and tertiary butyl bromides in THF.
