87639-46-1Relevant academic research and scientific papers
Synthesis of 2-Substituted Cyclobutanones by a Suzuki Reaction and Dephosphorylation Sequence
Koudelka, Jakub,Tobrman, Tomá?
, p. 3260 - 3269 (2021/06/25)
We report a novel process for the preparation of 2-substituted cyclobutanones. Such a method relies on the cross-coupling reaction of bromocyclobutenyl diethyl phosphate with either boronic acids or organozinc reagents. Dephosphorylation of the prepared 2-substituted cyclobutenyl phosphates affords 2-substituted cyclobutanones. We observed that the course of the dephosphorylation reaction depends on the properties of the substituents found on the cyclobutene nucleus. The presence of groups capable of stabilizing the negative charge is necessary for ring opening of cyclobutanones. The scope of the reported process for the preparation of 2-substituted cyclobutanones has also been extended to the preparation of cyclobutenyl sulfides.
Copper-Catalyzed Enantioselective Arylation via Radical-Mediated C-C Bond Cleavage: Synthesis of Chiral ω,ω-Diaryl Alkyl Nitriles
Cui, Guo-Qing,Dai, Jing-Cheng,Li, Yan,Li, Yuan-Bo,Hu, Duo-Duo,Bian, Kang-Jie,Sheng, Jie,Wang, Xi-Sheng
supporting information, p. 7503 - 7507 (2021/10/02)
The first example of copper-catalyzed ring-opening, enantioselective arylation of cyclic ketoxime esters to access ω,ω-diaryl alkyl nitriles has been developed in high yield (up to 92% yield) with excellent enantioselectivity (up to 91% ee). Side-arm bis(oxazoline) ligand plays a significant role in this asymmetric catalytic transformation, which provides an efficient route to construct diverse chiral ω,ω-diaryl alkyl nitriles. Synthetic utility has also been demonstrated in the further derivatization of the ω,ω-diaryl alkyl nitrile to the corresponding amide.
Enantioselective Radical Ring-Opening Cyanation of Oxime Esters by Dual Photoredox and Copper Catalysis
Chen, Jun,Wang, Peng-Zi,Lu, Bin,Liang, Dong,Yu, Xiao-Ye,Xiao, Wen-Jing,Chen, Jia-Rong
supporting information, p. 9763 - 9768 (2019/11/29)
Catalytic enantioselective chemical reactions involving highly reactive radical species remain largely unexplored. We report herein for the first time a novel enantioselective radical ring-opening cyanation of redox-active oxime esters by dual photoreodox
Cu-Catalyzed Redox-Neutral Ring Cleavage of Cycloketone O-Acyl Oximes: Chemodivergent Access to Distal Oxygenated Nitriles
Ai, Wenying,Liu, Yaqian,Wang, Qian,Lu, Zhonglin,Liu, Qiang
supporting information, p. 409 - 412 (2018/01/27)
A chemodivergent copper-catalyzed ring opening of cycloketone oximes via radical-mediated C-C bond cleavage under redox-neutral conditions is described. This method allows the divergent synthesis of γ- and δ-acyloxylated, alkoxylated, and hydroxylated nitriles while avoiding the use of toxic cyanide reagents. Moreover, these reactions proceed under very mild conditions with good functional group tolerance. Notably, ring-opening reactions of the less-strained substrate cyclopentanone oxime also proceeded well under the established conditions.
2,2-Dimethyl cyclopentanones by acid catalyzed ring expansion of isopropenylcyclobutanols. A short synthesis of (±)-α-cuparenone and (±)-herbertene
Bernard, Angela M.,Frongia, Angelo,Secci, Francesco,Piras, Pier P.
, p. 3853 - 3855 (2007/10/03)
2,2-Dimethyl cyclopentanones are readily prepared by acid catalyzed ring expansion of isopropenylcyclobutanols; the method allows ready access to the family of sesquiterpenes cuparanes and herbertanes, as demonstrated by the synthesis of (±)-α-cuparenone
Ring-enlargement of Cyclopropylacylsilanes with Sulfuric or Triflic Acid. Selective Formation of Cyclobutanones or 2-Silyl-4,5-dihydrofurans
Nakajima, Tadashi,Segi, Masahito,Mituoka, Takeshi,Fukute, Yasuyuki,Honda, Mitsunori,Naitou, Kaneyuki
, p. 1667 - 1670 (2007/10/02)
Reaction of cyclopropylacylsilanes with sulfuric or triflic acid in aprotic solvent affords the corresponding cyclobutanone or 2-silyl-4,5-dihydrofuran derivatives, depending upon the substituents on the three-membered ring or acid used.The use of triflic
Vinyl Cations. 41. Influence of 4-Aryl and 4-Alkyl Substituents on the ?-Route Solvolyses of Homopropargyl Esters
Collins, Clair J.,Hanack, Michael,Stutz, Herbert,Auchter, Gerhard,Schoberth, Winfried
, p. 5260 - 5268 (2007/10/02)
The four 4-substituted-homopropargyl tosylates and triflates 6b-e (R=phenyl, p-tolyl, anisyl, and cyclopropyl) have been synthesized and solvolyzed under various conditions, as have 2-cyclopropyl-1-cyclobutenyl triflate (11-OTf) and nonaflate (11-ONf).In addition, the solvolyses of pent-3-yn-1-yl tosylate (6a-OTs, R=methyl) and triflate (prepared previously) are reported.The ratios of C-3 ring to C-4 ring 3 ring/C4ring)> products are recorded for the reactions in various solvents.As expected, ring closure (kΔ) increases and solvent displacement (kS, SN2) decreases with decreasing nucleophilicity of solvent.Temperature effects are noted for the sovolyses of tosylates 6a-e in 100percent TFE buffered with Na2CO3 in which kΔ increases with increasing temperature.The result is explained by decomposition of the intimate ion pair with temperature, whereupon elimination to the enyne becomes smaller and ring closure (kΔ) increases at the expense of elimination.The possibility of intervention of nonclassical vinyl cations is discussed, as are other mechanistic implications.
