1009-81-0Relevant articles and documents
Branched/linear selectivity in palladium-catalyzed allyl-allyl cross-couplings: the role of ligands
Ardolino, Michael J.,Morken, James P.
, p. 6409 - 6413 (2015)
Abstract While Pd-catalyzed allyl-allyl cross-couplings in the presence of small-bite-angle bidentate ligands reliably furnish the branched regioisomer with high levels of selectivity, cross-couplings in the presence of large-bite-angle bidentate ligands
A regioselectivity switch in Pd-catalyzed hydroallylation of alkynes
Ji, Ding-Wei,Hu, Yan-Cheng,Zheng, Hao,Zhao, Chao-Yang,Chen, Qing-An,Dong, Vy M.
, p. 6311 - 6315 (2019/07/04)
By exploiting the reactivity of a vinyl-Pd species, we control the regioselectivity in hydroallylation of alkynes under Pd-hydride catalysis. A monophosphine ligand and carboxylic acid combination promotes 1,5-dienes through a pathway involving isomerization of alkynes to allenes. In contrast, a bisphosphine ligand and copper cocatalyst favor 1,4-dienes via a mechanism that involves transmetalation. Our study highlights how to access different isomers by diverting a common organometallic intermediate.
"Design" of boron-based compounds as pro-nucleophiles and co-catalysts for indium(I)-catalyzed allyl transfer to various Csp 3-type electrophiles
Dao, Hai Thanh,Schneider, Uwe,Kobayashi, Shu
experimental part, p. 2522 - 2529 (2012/07/13)
We have recently uncovered a general indium(I)-catalyzed method for allylations and propargylation of acetals and ketals with a water- and air-stable allyl boronate. By using a more reactive allyl borane, we have successfully extended this methodology to the more challenging C-C coupling with ethers. Herein, we report an improved methodology for the indium(I)-catalyzed allylation of acetals and ethers, through combination of the allyl boronate with a commercially available "hard" Lewis acid, B-methoxy-9-BBN (BBN=borabicyclo[3.3.1]nonane), as an effective co-catalyst. Significantly, our work highlights for the first time the correlation between the Lewis acidity of "electrophilic" boron-based compounds and their " nucleophilic" reactivity in Csp3-Csp3 couplings, catalyzed by a "soft" low-oxidation main group metal. In addition, we also report several applications of these methodologies to the selective synthesis of various carbohydrate derivatives. Copyright
Indium(i)-catalyzed alkyl-allyl coupling between ethers and an allylborane
Dao, Hai Thanh,Schneider, Uwe,Kobayashi, Shu
supporting information; experimental part, p. 692 - 694 (2011/03/22)
An efficient method for alkyl-allyl cross-coupling between ethers and a 9-BBN-derived allylborane catalyzed by indium(i) triflate has been developed. The allylborane proved to be essential to obtain the desired products in high yields. The reaction displayed good substrate scope including high functional group tolerance. The Royal Society of Chemistry 2011.
Pd-catalyzed enantioselective allyl-allyl cross-coupling
Zhang, Ping,Brozek, Laura A.,Morken, James P.
supporting information; experimental part, p. 10686 - 10688 (2010/11/04)
The Pd-catalyzed cross-coupling of allylic carbonates and allylB(pin) is described. The regioselectivity of this reaction is sensitive to the bite angle of the ligand, with small-bite-angle ligands favoring the branched substitution product. This mode of
Palladium(0) versus nickel(0) catalysis in selective functional- grouptolerant sp3-sp3 carbon-carbon bond formations
Flegeau, Emmanuel Ferrer,Schneider, Uwe,Kobayashi, Shue
experimental part, p. 12247 - 12254 (2010/06/11)
We have uncovered Pd°-catalyzed intermolecular nonsymmetrical Suzuki-Miyaura-type sp3-sp3 C-C bond formations between allyl carbonates and nontoxic allyl, allenyl, or propargyl boronates. This report represents the first use of these
Nickel-catalyzed allylation of allyl carbonates with homoallyl alcohols via retro-allylation providing 1,5-hexadienes
Sumida, Yuto,Hayashi, Sayuri,Hirano, Koji,Yorimitsu, Hideki,Oshima, Koichiro
experimental part, p. 1629 - 1632 (2009/04/10)
A highly efficient and mild method for the synthesis of 1,5-hexadienes, nickel-catalyzed reactions of Boc-protected allyl alcohols with homoallyl alcohols, has been developed. Nickel-mediated retro-allylation allows for the use of homoallyl alcohols as allylmetal equivalents in the synthesis of 1,5-hexadienes.2008 American Chemical Society.
Synthesis of 2-phenyl-2-cycloalkenones via palladium-catalyzed tandem epoxide isomerization-intramolecular aldol condensation
Kim, Ji-Hyun,Kulawiec, Robert J.
, p. 3107 - 3110 (2007/10/03)
We have extended the scope of our palladium-catalyzed tandem epoxide isomerization/aldol condensation reaction to encompass intramolecular condensations, which provide facile access to conjugated cycloalkenones from epoxy aldehydes or diepoxides. For example, reaction of 5,6-epoxy-6- phenylhexanal with Pd(OAc)2-PBu3 catalyst in the presence of NaHCO3 and 3A molecular sieves forms 2-phenyl-2-cyclopentenone (80%). Similarly, 1,2;5,6-diepoxy-1-phenylhexane affords 3-methyl-2-phenyl-2-cyclopentenone (72%). The observation of dicarbonyl intermediates (e.g., 1-phenyl-2,5- hexanedione in the latter case) demonstrates that the reaction proceeds via Pd-catalyzed isomerization of the diepoxide to the diketone, followed by base-catalyzed aldol condensation.
Photocleavage of Benzyl-Sulfide Bonds
Fleming, Steven A.,Jensen, Anton W.
, p. 7135 - 7137 (2007/10/02)
The nucleoside transport inhibitor 6--9-(β-D-ribofuranosyl)purine, NBMPR, has been used successfully in photoaffinity labeling.We have studied the mechanism for photocleavage of the benzyl-sulfur bond by using substituted benzyl phenyl sulfides as analogues of NBMPR.This has enabled us to enhance the photoreactivity of the benzyl-sulfur bond.We have also performed "radical clock" studies with a hexenyl side chain to trap reactive intermediates.The mechanistic interpretation from the substituent and side chain studies is that the benzyl-sulfur moiety is photocleaved via a homolytic pathway.
