Metal-Free Direct C-H β-Carbonyl Alkylation of Heteroarenes with Cyclopropanols Mediated by K<sub>2</sub>
S<sub>2</sub>
O<sub>8</sub>
作者:Qiang Liu、Qiang Wang、Guanqun Xie、Zeyang Fang、Shujiang Ding、Xiaoxia Wang
DOI:10.1002/ejoc.202000289
日期:2020.5.10
direct C–H β‐carbonyl alkylation of heteroarenes has been achieved through K2S2O8‐mediated ring‐opening of cyclopropanols. A wide scope of substrates, such as various substituted quinolines and isoquinolines, pyridines, pyridazine, benzo[d]thiazole, and phenanthroline, underwent the β‐carbonyl alkylation efficiently and afforded the β‐heteroarylated ketones in moderate to excellent yields.
medicinal chemistry and organic synthesis is known. An efficient route to γ-keto sulfones through a metal-free reaction of cyclopropanols, sulfur dioxide and electron-deficient olefins is achieved. This reaction proceeds smoothly under mild conditions without the need of catalyst, oxidant or additive. A plausible mechanism is proposed, which undergoes through γ-keto sulfinate intermediate generated
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
A route to γ-keto sulfones through a metal-free reaction of cyclopropanols, DABCO ⋅ (SO2)2 and alkyl halides is described. This reaction occurs under mild conditions in the absence of any catalysts, additives, or oxidants. Various functional groups including as ester, amino, methoxy, bromo, trifluoromethyl, nitro and carbonyl are tolerated well in this transformation, and the corresponding γ-keto sulfones
4-HO-TEMPO-Catalyzed Redox Annulation of Cyclopropanols with Oxime Acetates toward Pyridine Derivatives
作者:Jun-Long Zhan、Meng-Wei Wu、Dian Wei、Bang-Yi Wei、Yu Jiang、Wei Yu、Bing Han
DOI:10.1021/acscatal.9b00832
日期:2019.5.3
for the synthesis of pyridines through the annulation of cyclopropanols and oxime acetates has been developed. This protocol features good functional group tolerance and high chemoselectivity and also promises to be efficient for the late-stage functionalization of skeletons of drugs and natural products. Mechanism studies indicate that the reaction involves the in situ generated α,β-unsaturated ketones