1145-92-2Relevant articles and documents
Synthesis, structure, and reactivity of iminosulfonium ylides bearing an α-carbonyl group
Fujii, Takayoshi,Suzuki, Tetsuya,Sato, Takashi,Horn, Ernst,Yoshimura, Toshiaki
, p. 6151 - 6154 (2001)
Treatment of methyl(methylimino)diphenylsulfonium tetraphenylborate (3) with NaH and subsequent acylation produced a new type of iminosulfonium ylides bearing an α-carbonyl group 5. The molecular structure of iminosulfonium phenacylide 5a was determined by X-ray crystallographic analysis. The ylide 5 reacted further with methyl triflate affording the corresponding novel alkylidenesulfonium salts 6.
"Instant methylide" modification of the Corey-Chaykovsky cyclopropanation reaction
Ciaccio, James A.,Aman, Courtney E.
, p. 1333 - 1341 (2006)
Treatment of various electron-deficient alkenes in DMSO with stable, dry, equimolar mixtures of either Me3S(O)I/KOt-Bu or Me 3S(O)I/NaH cleanly afforded the corresponding substituted cyclopropanes in good yields and short reaction ti
Hantzsch Ester-Mediated Photochemical Transformations in the Ketone Series: Remote C(sp3)-H Arylation and Cyclopentene Synthesis through Strain Release
Paternoga, Jan,Kühlborn, Jonas,Rossdam, Nils Ole,Opatz, Till
supporting information, p. 3232 - 3248 (2021/02/27)
A metal-free Hantzsch ester-mediated synthesis of cyclopentenylketones as well as O-hetarylketones starting from ketocyclopropanes under eco-friendly conditions was developed. The versatility of the developed conditions is shown by reacting ketocyclopropanes in both a formal [3 + 2] cycloaddition with terminal alkynes (further investigated using theoretical calculations) and a radical C-C-coupling with cyanopyridines. The newly developed methodologies were later on utilized as a downstream reaction for photogenerated cyclopropanes combining UV and visible light photochemistry. Following this procedure, a UV-driven Norrish-Yang-type reaction induces the ring strain of the intermediates, which serves as activation energy for the subsequent ring transformation.
Facile synthesis of libraries of functionalized cyclopropanes and oxiranes using ionic liquids – A new approach to the classical Corey-Chaykovsky reaction
Malunavar, Shruti S.,Sutar, Suraj M.,Prabhala, Pavankumar,Savanur, Hemantkumar M.,Kalkhambkar, Rajesh G.,Aridoss, Gopalakrishnan,Laali, Kenneth K.
supporting information, (2021/09/13)
The potential of [PAIM][NTf2]/BMIM-ILs as a base/solvent in the Corey-Chaykovsky reaction is demonstrated by the facile synthesis of libraries of functionalized cyclopropanes from enones and oxiranes from aldehydes and ketones, at room temperature in respectable isolated yields. To demonstrate their application, the synthesized epoxides were employed as substrates for the synthesis of a library of 2,3-disubstituted quinolines, using [BMIM(SO3H)][OTf]/[BMIM][PF6] as a catalyst/solvent. The potential for recycling/reuse of the IL solvents was also explored.
Harnessing Applied Potential: Selective β-Hydrocarboxylation of Substituted Olefins
Alkayal, Anas,Buckley, Benjamin R.,Malkov, Andrei V.,Montanaro, Stephanie,Tabas, Volodymyr,Wright, Iain A.
supporting information, (2020/02/13)
The construction of carboxylic acid compounds in a selective fashion from low value materials such as alkenes remains a long-standing challenge to synthetic chemists. In particular, β-addition to styrenes is underdeveloped. Herein we report a new electrosynthetic approach to the selective hydrocarboxylation of alkenes that overcomes the limitations of current transition metal and photochemical approaches. The reported method allows unprecedented direct access to carboxylic acids derived from β,β-trisubstituted alkenes, in a highly regioselective manner.
Bromomethyl Silicate: A Robust Methylene Transfer Reagent for Radical-Polar Crossover Cyclopropanation of Alkenes
Luo, Wenping,Fang, Yewen,Zhang, Li,Xu, Tianhang,Liu, Yongjun,Li, Yan,Jin, Xiaoping,Bao, Jiakan,Wu, Xiaodong,Zhang, Zongyong
supporting information, p. 1778 - 1781 (2020/03/11)
A general protocol for visible-light-induced cyclopropanation of alkenes was developed with bromomethyl silicate as a methylene transfer reagent, offering a robust tool for accessing highly valuable cyclopropanes. In addition to α-aryl or methyl-substituted Michael acceptors and styrene derivatives, the unactivated 1,1-dialkyl ethylenes were also shown to be viable substrates. Apart from realizing the cyclopropanation of terminal alkenes, the methyl transfer reaction has been further demonstrated to be amenable to the internal olefins. The photocatalytic cyclopropanation of 1,3-bis(1-arylethenyl)benzenes was also achieved, giving polycyclopropane derivatives in excellent yields. With late-stage cyclopropanation as the key strategy, the synthetic utility of this transformation was also demonstrated by the total synthesis of LG100268.
Rhodium Porphyrin Catalyzed Regioselective Transfer Hydrogenolysis of C-C σ-Bonds in Cyclopropanes with iPrOH
Chen, Chen,Feng, Shiyu,Chan, Kin Shing
supporting information, p. 2582 - 2589 (2019/07/02)
A new rhodium porphyrin catalyzed regioselective transfer hydrogenolysis of both activated and unactivated cyclopropanes employing iPrOH as the hydrogen source was discovered. The reaction mechanism for the C-C σ-bond activation of cyclopropanes was identified through an initial radical substitution with rhodium(II) metalloporphyrin radical to give a rhodium porphyrin alkyl, followed by hydrogenolysis with iPrOH to give the corresponding acyclic alkanes and regenerate rhodium(II) metalloporphyrin radical.
Enantioselective Copper-Catalyzed 1,5-Cyanotrifluoromethylation of Vinylcyclopropanes
Zhang, Zi-Qi,Meng, Xiang-Yu,Sheng, Jie,Lan, Quan,Wang, Xi-Sheng
, p. 8256 - 8260 (2019/10/16)
A copper-catalyzed enantioselective 1,5-cyanotrifluoromethylation of vinylcyclopropanes has been developed using a radical relay strategy. This asymmetric reaction has demonstrated high enantioselective control, broad substrate scope, and mild conditions. Initiated by the in situ generated CF3 radical from Togni's reagent, this method offers a new solution for remote enantioselective bifunctionalization of alkenes and thus provides a straightforward way for the synthesis of chiral CF3-containing internal alkenylnitriles.
Nucleophilic Ring Opening of Donor-Acceptor Cyclopropanes Catalyzed by a Br?nsted Acid in Hexafluoroisopropanol
Richmond, Edward,Vukovi?, Vuk D.,Moran, Joseph
supporting information, p. 574 - 577 (2018/02/10)
A general, Br?nsted acid catalyzed method for the room temperature, nucleophilic ring opening of donor-acceptor cyclopropanes in fluorinated alcohol solvent, HFIP, is described. Salient features of this method include an expanded cyclopropane scope, including those bearing single keto-acceptor groups and those bearing electron-deficient aryl groups. Notably, the catalytic system proved amenable to a wide range of nucleophiles including arenes, indoles, azides, diketones, and alcohols.
Redox-Neutral Photocatalytic Cyclopropanation via Radical/Polar Crossover
Phelan, James P.,Lang, Simon B.,Compton, Jordan S.,Kelly, Christopher B.,Dykstra, Ryan,Gutierrez, Osvaldo,Molander, Gary A.
supporting information, p. 8037 - 8047 (2018/07/03)
A benchtop stable, bifunctional reagent for the redox-neutral cyclopropanation of olefins has been developed. Triethylammonium bis(catecholato)iodomethylsilicate can be readily prepared on multigram scale. Using this reagent in combination with an organic photocatalyst and visible light, cyclopropanation of an array of olefins, including trifluoromethyl- and pinacolatoboryl-substituted alkenes, can be accomplished in a matter of hours. The reaction is highly tolerant of traditionally reactive functional groups (carboxylic acids, basic heterocycles, alkyl halides, etc.) and permits the chemoselective cyclopropanation of polyolefinated compounds. Mechanistic interrogation revealed that the reaction proceeds via a rapid anionic 3-exo-tet ring closure, a pathway consistent with experimental and computational data.
