3145-76-4Relevant academic research and scientific papers
Silylium-Ion-Promoted Ring-Opening Hydrosilylation and Disilylation of Unactivated Cyclopropanes
Bonetti, Vittorio,Klare, Hendrik F. T.,Oestreich, Martin,Roy, Avijit,Wang, Guoqiang,Wu, Qian
supporting information, (2020/02/04)
A silylium-ion-promoted ring-opening hydrosilylation of unactivated cyclopropanes is reported. The reaction is facilitated by the γ-silicon effect, and the regioselectivity is influenced by various stabilizing effects on the carbenium-ion intermediates, including the β-silicon effect. The experimental observations are in accord with the computed reaction mechanism. The work also showcases the ability of silylium ions to isomerize cyclopropyl to allyl groups, and the resulting α-olefins engage in a silylium-ion-mediated disilylation with hexamethyldisilane.
Mild Ring-Opening 1,3-Hydroborations of Non-Activated Cyclopropanes
Wang, Di,Xue, Xiao-Song,Houk, Kendall N.,Shi, Zhuangzhi
supporting information, p. 16861 - 16865 (2018/11/27)
The Brown hydroboration reaction, first reported in 1957, is the addition of B?H across an olefin in an anti-Markovnikov fashion. Here, we solved a long-standing problem on mild 1,3-hydroborations of non-activated cyclopropanes. A three-component system including cyclopropanes, boron halides, and hydrosilanes has been developed for borylative ring-opening of cyclopropanes following the anti-Markovnikov rule, under mild reaction conditions. Density functional theory (M06-2X) calculations show that the preferred pathway involves a cationic boron intermediate which is quenched by hydride transfer from the silane.
Synergistic effect of additives on cyclopropanation of olefins
Cheng, Donghao,Huang, Deshun,Shi, Yian
supporting information, p. 5588 - 5591 (2013/09/12)
An efficient cyclopropanation of olefins with Zn(CH2I) 2, a catalytic amount of CCl3CO2H, and 1,2-dimethoxyethane at room temperature is described. A wide variety of olefins, including acid-sensitive substrates,
Cyclopropanation of alkenes with CH2I2/Et3Al by the phase-vanishing method based on fluorous phase screen
Matsubara, Hiroshi,Tsukida, Masaaki,Yasuda, Shinji,Ryu, Ilhyong
scheme or table, p. 951 - 954 (2009/04/04)
Phase-vanishing (PV) method using perfluorohexanes as a screen phase was applied to cyclopropanation reactions with CH2I2/Et2Zn and CH2I2/Et3Al. When Et3Al was used as a carbenoid generator, the reaction proceeded smoothly and desired cyclopropane derivatives were obtained in high yield. The PV cyclopropanation took 2 or 3 days to complete, however, reduction of reaction time by a factor of 2-3 was also achieved by vigorous stirring after the bottom CH2I2 layer disappeared.
Lanthanum metal-assisted cyclopropanation of alkenes with gem-dihaloalkanes
Nishiyama, Yutaka,Tanimizu, Hana,Tomita, Tsuyoshi
, p. 6405 - 6407 (2008/02/12)
It was confirmed that lanthanum metal was an efficient reagent for the reductive dehalogenation of gem-dihaloalkanes. When gem-dihaloalkanes were allowed to react with lanthanum metal in the presence of alkenes, cyclopropanation of the alkenes occurred under mild conditions giving the corresponding cyclopropanes in moderate to good yields.
Processing of cyclopropylarenes by toluene dioxygenase: Isolation and absolute configuration of metabolites
Finn, Kevin J.,Rochon, Lena,Hudlicky, Tomas
, p. 3606 - 3613 (2007/10/03)
Several arenes possessing a cyclopropyl substituent were subjected to enzymatic oxidation with toluene dioxygenase. The absolute configuration of metabolites was established by chemical means.
Iodomethylzinc phosphates: Powerful reagents for the cyclopropanation of alkenes
Lacasse, Marie-Christine,Poulard, Cyril,Charette, Andre B.
, p. 12440 - 12441 (2007/10/03)
A new family of zinc carbenoids derived from phosphoric acids was developed and used in the cyclopropanation of allylic alcohols and ethers and also of unfunctionalized olefins. The use of the chiral phosphoric acid of a 3,3′-disubstituted BINOL leads to efficient stereocontrol, affording the cyclopropanes of allylic and homoallylic ethers with complete conversions and up to 93% ee. A catalytic version of this reaction using 10 mol % of the chiral phosphate reagent is also disclosed. Copyright
Highly diastereoselective hydrostannylation of allyl and homoallyl alcohols with dibutyl(trifluoromethanesulfoxy)stannane
Miura, Katsukiyo,Wang, Di,Hosomi, Akira
, p. 9366 - 9367 (2007/10/03)
Dibutyl(trifluoromethanesulfoxy)stannane (Bu2Sn(OTf)H, 1a) was found to be very valuable for highly diastereoselective homolytic hydrostannylation of allyl and homoallyl alcohols. α,β-Disubstituted allyl alcohols and α,γ-disubstituted homoallyl alcohols were converted into γ- and δ-stannylated alcohols with high 1,2-syn and 1,3-syn diastereoselectivity, respectively. The origin of the stereochemical outcomes can be rationalized by conformational fixation of the intermediary β-stannylalkyl radical by coordination of the hydroxy group to the Lewis acidic tin center. Copyright
A Novel Class of Tunable Zinc Reagents (RXZnCH2Y) for Efficient Cyclopropanation of Olefins
Lorenz, Jon C.,Long, Jiang,Yang, Zhiqiang,Xue, Song,Xie, Yinong,Shi, Yian
, p. 327 - 334 (2007/10/03)
A class of zinc reagents (RXZnCH2Y) generated with an appropriate organozinc is very effective for the cyclopropanation of olefins. The reactivity and selectivity of these reagents can be regulated by tuning the electronic and steric nature of the RX group on Zn. A reasonable level of enantioselectivity was obtained for the cyclopropanation of unfunctionalized olefins when a chiral (iodomethyl)zinc species was used, providing a valuable approach for the asymmetric cyclopropanation of unfunctionalized olefins.
Zirconium-mediated conversion of homoallylic ethers into cyclopropane derivatives
Gandon, Vincent,Laroche, Christophe,Szymoniak, Jan
, p. 4827 - 4829 (2007/10/03)
Homoallylic ethers react with Cp2ZrCl2/2 n-BuLi reagent to afford cyclopropane derivatives. Cyclopropylcarbinyl-homoallyl rearrangements involving zirconium species are observed depending on the substrate structure.
