16580-35-1Relevant academic research and scientific papers
A Unified Catalytic Asymmetric (4+1) and (5+1) Annulation Strategy to Access Chiral Spirooxindole-Fused Oxacycles
Gao, Min,Gong, Xiangnan,Hu, Lin,Luo, Yanshu,Xia, Yuanzhi,Xu, Qianlan,Zhao, Yukun
supporting information, p. 19813 - 19820 (2021/08/03)
A unified catalytic asymmetric (N+1) (N=4, 5) annulation reaction of oxindoles with bifunctional peroxides has been achieved in the presence of a chiral phase-transfer catalyst (PTC). This general strategy utilizes peroxides as unique bielectrophilic four- or five-atom synthons to participate in the C?C and the subsequent umpolung C?O bond-forming reactions with one-carbon unit nucleophiles, thus providing a distinct method to access the valuable chiral spirooxindole-tetrahydrofurans and -tetrahydropyrans with good yields and high enantioselectivities under mild conditions. DFT calculations were performed to rationalize the origin of high enantioselectivity. The gram-scale syntheses and synthetic utility of the resultant products were also demonstrated.
Synthesis of Functionalized Aliphatic Acid Esters via the Generation of Alkyl Radicals from Silylperoxyacetals
Matsumoto, Akira,Shiozaki, Yoko,Sakurai, Shunya,Maruoka, Keiji
supporting information, p. 2431 - 2434 (2021/08/07)
We describe a catalytic method for the synthesis of a variety of functionalized aliphatic acid esters using silylperoxyacetals, which are versatile alkyl radical precursors with a terminal ester moiety. In the presence of an appropriate transition-metal catalyst, the in situ generation of alkyl radicals and the subsequent bond-forming process proceeds smoothly to afford synthetically valuable aliphatic acid derivatives. The present method can be applied to the efficient synthesis of a pharmaceutically important 1,1-diarylalkane motif. In addition, a novel strategy for the synthesis of structurally diverse hydroxy acid derivatives via a C?O bond formation process that utilizes TEMPO has been developed.
Spiro- and dispiro-1,2-dioxolanes: Contribution of iron(II)-mediated one-electron vs two-electron reduction to the activity of antimalarial peroxides
Wang, Xiaofang,Dong, Yuxiang,Wittlin, Sergio,Creek, Darren,Chollet, Jacques,Charman, Susan A.,Tomas, Josefina Santo,Scheurer, Christian,Snyder, Christopher,Vennerstrom, Jonathan L.
, p. 5840 - 5847 (2008/03/17)
Fourteen spiro- and dispiro-1,2-dioxolanes were synthesized by peroxycarbenium ion annulations with alkenes in yields ranging from 30% to 94%. Peroxycarbenium ion precursors included triethylsilyldiperoxyketals and -acetals derived from geminal dihydroperoxides and from a new method employing triethylsilylperoxyketals and -acetals derived from ozonolysis of alkenes. The 1,2-dioxolanes were either inactive or orders of magnitude less potent than the corresponding 1,2,4-trioxolanes or artemisinin against P. falciparum in vitro and P. berghei in vivo. In reactions with iron(II), the predominant reaction course for 1,2-dioxolane 3a was two-electron reduction. In contrast, the corresponding 1,2,4-trioxolane 1 and the 1,2,4-trioxane artemisinin undergo primarily one-electron iron(II)-mediated reductions. The key structural element in the latter peroxides appears to be an oxygen atom attached to one or both of the peroxide-bearing carbon atoms that permits rapid β-scission reactions (or H shifts) to form primary or secondary carbon-centered radicals rather than further reduction of the initially formed Fe(III) complexed oxy radicals.
Ozonolysis of Vinyl Ethers in Solution and on Polyethylene
Griesbaum, Karl,Kim, Woo-Sun,Nakamura, Norinaga,Mori, Mitsuyuki,Nojima, Masatomo,Shigekazu, Kusabayashi
, p. 6153 - 6161 (2007/10/02)
Ozonolyses of the vinyl ethers 1a-f in methanol afforded almost exclusively the corresponding α-methoxy hydroperoxides 4, suggesting the preferred formation of the carbonyl oxides 2.In aprotic solvents including methyl formate, the predominant modes of decay of the carbonyl oxides 2 were cyclodimerization, reduction, and rearrangement, yet no ozonide formation.By contrast, ozonolyses of 1a-f on polyethylene gave the α-methoxy-substituted ozonides 14 in fair yields.Ozonolyzes of 1a-f in the presence of added carbonyl compounds 6 in methylene chloride or ether yielded the corresponding cross ozonides.Judged from the ozonide yields, the reactivities of the carbonyl compounds follow the sequence: (ClCH2)2C=O > ClCH2COCH3 > (CH3)2C=O and 2-CF3C6H4CHO > PhCHO.
