97552-09-5Relevant academic research and scientific papers
Stereoselective Functionalization of Racemic Cyclopropylzinc Reagents via Enantiodivergent Relay Coupling
An, Lun,Tong, Fei-Fei,Zhang, Shu,Zhang, Xingang
supporting information, p. 11884 - 11892 (2020/08/06)
Efficient construction of optically pure molecules from readily available starting materials in a simple manner is an ongoing goal in asymmetric synthesis. As a straightforward route, transition-metal-catalyzed enantioconvergent coupling between widely available secondary alkyl electrophiles and organometallic nucleophiles has emerged as a powerful strategy to construct chiral center(s). However, the scope of racemic secondary alkylmetallic nucleophiles for this coupling remains limited in specific substrates because of the difficulties in stereoselective formation of the key alkylmetal intermediates. Here, we report an enantiodivergent strategy to efficiently achieve an array of synthetically useful chiral cyclopropanes, including chiral fluoroalkylated cyclopropanes and enantiomerically enriched cyclopropanes with chiral side chains, from racemic cyclopropylzinc reagents. This strategy relies on a one-pot, two-step enantiodivergent relay coupling process of the racemic cis-cyclopropylzinc reagents with two different electrophiles, which involves kinetic resolution of racemic cis-cyclopropylzinc reagents through a nickel-catalyzed enantioselective coupling with alkyl electrophiles, followed by a stereospecific relay coupling of the remaining enantiomeric cyclopropylzinc reagent with various electrophiles, to produce two types of functionalized chiral cyclopropanes with opposite configurations on the cyclopropane ring. These chiral cyclopropanes are versatile synthons for diverse transformations, rendering this strategy effective for obtaining structurally diversified molecules of medicinal interest.
Stereoselective Desymmetrization of gem-Diborylalkanes by “Trifluorination”
Kumar, Nivesh,Reddy, Reddy Rajasekhar,Masarwa, Ahmad
supporting information, p. 8008 - 8012 (2019/05/28)
An efficient and general method for the chemoselective synthesis of unsymmetrical gem-diborylalkanes is reported. This method is based on a late-stage desymmetrization through nucleophilic “trifluorination”, providing chiral gem-diborylalkanes bearing a trifluoroborate group. The reaction offers a highly modular and diastereoselective approach towards the synthesis of gem-diborylcyclopropanes. The utility of the gem-diborylalkane building blocks was demonstrated by selective post-functionalization of the trifluoroborate group. These functionalizations include inter- and intra- Pd-catalyzed Suzuki–Miyaura coupling reactions.
A Modular Approach to the Synthesis of gem-Disubstituted Cyclopropanes
Harris, Michael R.,Wisniewska, Hanna M.,Jiao, Wenhua,Wang, Xiaochun,Bradow, James N.
supporting information, p. 2867 - 2871 (2018/05/29)
A diastereoselective, Pd-catalyzed Suzuki-Miyaura coupling reaction of geminal bis(boryl)cyclopropanes has been developed. The reaction offers a highly modular approach to the synthesis of tertiary cyclopropylboronic esters. The resulting boronic esters may be further functionalized to afford a range of gem-disubstituted cyclopropanes, which represent an important structural motif in the pharmaceutical industry. Sequential Suzuki-Miyaura cross-coupling reactions of gem-bis(boryl)cyclopropanes are also reported. The coupling protocols are compatible with a broad range of functionalized aryl and heteroaryl bromides.
gem-Dihalocyclopropane formation by iron/copper activation of tetrahalomethanes in the presence of nucleophilic olefins. Evidence for a carbene pathway
Léonel, Eric,Lejaye, Michael,Oudeyer, Sylvain,Paugam, Jean Paul,Nédélec, Jean-Yves
, p. 2635 - 2638 (2007/10/03)
The activation of CBr4 and CCl4 by a bimetallic iron/copper couple in acetonitrile is a new, inexpensive, nontoxic and efficient procedure for gem-dibromo- and gem-dichloromethylenation of nucleophilic alkenes. This new route to gem-dihalocyclopropanes involves dihalocarbene species.
Stereomutation in the Seyferth Reaction
Lambert, Joseph B.,Larson, Eric G.,Bosch, Richard J.,Vrucht, Mollie L. E. Te
, p. 5443 - 5447 (2007/10/02)
The cyclopropanation reaction between dibromomethylene (:CBr2) from the Seyferth reagent (PhHgCBr3) and electron-deficient alkenes is nonstereospecific.Thus fumaronitrile, styrene-cis-β-d, and trans-1,2-dichloroethene give mixtures of the respective cis a
