20883-16-3Relevant academic research and scientific papers
P-Chiral Monophosphorus Ligands for Asymmetric Copper-Catalyzed Allylic Alkylation
Xiong, Wenrui,Xu, Guangqing,Yu, Xinhong,Tang, Wenjun
supporting information, p. 4003 - 4013 (2019/06/24)
Asymmetric copper-catalyzed allylic alkylation between allyl bromides and alkyl Grignard reagents using a P-chiral monophosphorus ligand is described. A range of terminal olefins bearing tertiary or quaternary carbon centers were formed in good branched/linear selectivities and excellent enantioselectivities at copper loadings as low as 0.5 mol %.
Triflimide-catalyzed allyl-allyl cross-coupling: A metal-free allylic alkylation
Ding, Feiqing,William, Ronny,Wang, Fei,Liu, Xue-Wei
supporting information; experimental part, p. 8709 - 8711 (2012/10/08)
A highly efficient metal-free intermolecular C(sp3)-C(sp3) allyl-allyl cross-coupling protocol between allyl acetates and allyltrimethylsilanes, which proceeded smoothly in the presence of catalytic triflimide to form 1,5-dienes with good to excellent regioselectivity, has been developed.
Stereoselective reductions of N-Boc-hexahydro-1H-indolin-5(6H)-ones
Brodney, Michael A.,Cole, Marcus L.,Freemont, Jamie A.,Kyi, Stella,Junk, Peter C.,Padwa, Albert,Riches, Andrew G.,Ryan, John H.
, p. 1939 - 1943 (2007/10/03)
We report the divergent effects of a 3a-methyl and 3a-phenyl substituent on the chemoselectivity and stereoselectivity of reduction of the enamide moiety of N-Boc-hexahydro-1H-indolin-5(6H)-ones. Under ionic reduction conditions (triethylsilane/trifluoroacetic acid) the enamide group of 3a-methyl-N-Boc-hexahydro-1H-indolin-5(6H)-one was reduced to afford exclusively a cis ring-fused product. For the 3a-phenyl substituted analogue more forcing conditions (sodium cyanoborohydride at pH 2-2.5) were required and resulted in the selective reduction of the enamide group to give a trans ring-fused product as well as reduction of the ketone group.
[(NHC)Au1]-catalyzed rearrangement of allylic acetates
Marion, Nicolas,Gealageas, Ronan,Nolan, Steven P.
, p. 2653 - 2656 (2008/02/09)
Equation Presented [(NHC)AuCl] complexes (NHC = N-heterocyclic carbene), in conjunction with a silver salt, were found to efficiently catalyze the rearrangement of allylic acetates under both conventional and microwave-assisted heating. The optimization of several reaction parameters (solvent, silver salt, and ligand) as well as a study of the reaction scope are reported. The steric hindrance of the ligand bound to gold was found crucial for the outcome of the reaction as only extremely bulky ligands permitted the isomerization.
Studies of the formation of all-carbon quaternary centres, en route to lyngbyatoxin A. A comparison of phenyl and 7-substituted indole systems.
Tonder, Janne E,Hosseini, Masood,Ahrenst, Alex B,Tanner, David
, p. 1447 - 1455 (2007/10/03)
Copper mediated allylic substitutions and conjugate additions to geranyl, cinnamyl and allylic indole compounds have been investigated with the aim of finding a method for the creation of the all-carbon quaternary centre present in the natural product lyngbyatoxin A. Reaction conditions have been found giving a 68% SN2' selectivity in the copper mediated addition of PhMgBr to geranyl chloride, as well as 99% and 95% SN2' selectivity in the copper catalysed addition of EtMgBr to cinnamyl chloride and acetate, respectively. When the optimised reaction conditions were applied to the corresponding allylic compounds containing a 7-substituted indole moiety, the regioselectivity was reversed giving only the SN2 product. The allylic indole-containing substrates were also found to be unproductive in Pd- or Mo-catalysed SN2'-type substitution reactions. In related studies, copper catalysed conjugate addition of EtMgBr to the tricyclic lactam 6-methyl-pyrrolo[3,2,1-ij]quinolin-4-one gave a maximum of 20% of the 1,4-addition product.
On the regioselectivity of Pd-catalyzed additions of organoboronic acids to unsymmetrical alkynes
Kim, Nakjoon,Kim, Ki Seong,Gupta, Aruna Kumar,Oh, Chang Ho
, p. 618 - 619 (2007/10/03)
The Pd-catalyzed reaction of unsymmetrical alkynes 1 with organoboronic acids 2 gave a mixture of products 3 and 4, whose ratios were controlled by the electronic as well as steric effects of the substrates 1.
6-hydroxymethyl-1,2,4-trioxanes and derivatives: An alternative 1,2,4-trioxane synthesis from β′γ′-unsaturated β-hydroxyhydroperoxides
Bloodworth,Johnson, Karen A.
, p. 8057 - 8060 (2007/10/02)
Allylic hydroperoxides CH2:C(Ph)CH(OOH)CH2OX (X = H, CONHPh, Ac), from regiospecific photooxygenation of allylic alcohols CH3C(Ph):CHCH2OX, form hemiperoxyacetals with aldehydes or ketones which upon cyclisation with mercury(II) trifluoroacetate then reduction with sodium borohydride diastereoselectively afford 1,2,4-trioxanes with XOCH2 substituents at C-6.
Oxidation by Cobalt(III) Acetate. Part 8. Effects of Substituents on Product Distributions in Oxidation of Aromatic Olefins by Cobalt(III) Acetate
Morimoto, Takashi,Hirano, Masao,Koyama, Tsuyoshi
, p. 1109 - 1116 (2007/10/02)
Oxidation of aromatic olefins by cobalt(III) acetate in acetic acid under nitrogen gave both allylic acetates and glycol monoacetates.Disubstituted olefins were oxidized by the oxidant to give predominantly allylic acetates.Glycol monoacetates were minor products except for the case of 1-phenylisobutene which was slowly oxidized to give the corresponding glycol monoacetate.In the oxidation of tri- and tetra-substituted olefins, the yield of glycol monoacetate increased at the expense of that of allylic acetate.A mechanism, in which the reaction proceeds through a Co-co-ordinated radical kation formed by an one-electron abstraction from olefin by cobalt(III) acetate, is suggested.
