Cobalt-Catalyzed Regio- and Diastereoselective Formal [3 + 2] Cycloaddition between Cyclopropanols and Allenes
作者:Junfeng Yang、Qiao Sun、Naohiko Yoshikai
DOI:10.1021/acscatal.8b05114
日期:2019.3.1
reaction between a cyclopropanol and an allene viacyclopropanol ring opening, which affords a 3-alkylidenecyclopentanol derivative with high regio- and diastereoselectivities. The reaction tolerates monosubstituted, 1,1-disubstituted, and 1,3-disubstituted allenes and various functional groups. The reaction is proposed to proceed through carbometalation of the allene with a cobalt homoenolate followed by
Iron catalyzed tandem ring opening/1,6-conjugate addition of cyclopropanols with <i>p</i>-quinone methides: new access to γ,γ-diaryl ketones
作者:Sachin R. Shirsath、Sagar M. Chandgude、M. Muthukrishnan
DOI:10.1039/d1cc05997a
日期:——
An iron(III) catalyzed tandem ring opening/1,6-conjugate addition of cyclopropanols to p-quinone methides leading to γ,γ-diaryl ketones has been described. This catalytic protocol provides a novel and efficient method to access γ,γ-diaryl ketone derivatives in good to excellent yields with high functional group tolerance. Importantly, γ,γ-diaryl ketone can be further functionalized to give a versatile
reactions between a cyclopropanol and an oxabicyclic alkene via a cobalt homoenolate, which afford either an alkylative ring-opening product or a hydroalkylation product, with the counterion of the cobalt catalyst being a major chemoselectivity-controlling factor. A catalyst generated from cobalt(II) chloride and a chiral diphosphine promotes alkylative ring opening to afford 1,2-dihydronaphthalen-1-ol
Synthesis of 2-Substituted Quinolines <i>via</i>
Rhodium(III)-Catalyzed C-H Activation of Imidamides and Coupling with Cyclopropanols
作者:Xukai Zhou、Zisong Qi、Songjie Yu、Lingheng Kong、Yang Li、Wan-Fa Tian、Xingwei Li
DOI:10.1002/adsc.201601278
日期:2017.5.17
An efficient synthesis of 2-substituted quinolines from readily available cyclopropanols and imidamides has been developed, where the cyclopropanol acts as a C3 synthon. With the assistance of a bifunctional imidamide directing group, the reaction occurred via sequential C–H/C–C cleavage and C–C/C–N bond formation.
The site-selective C8-alkylation of quinolines has been accomplished using cyclopropyl alcohols as the alkylating agents and N-oxide as a weak chelating group in the presence of Co(III) catalysis via merging C–H/C–C bond activation. The use of cyclopropanol as the alkyl source, Co catalysis, substrate scope, HRMS analysis of the reaction intermediate, and late-stage mutation of drug molecules/natural