Enantioselective Type II Cycloaddition of Alkynes via C-C Activation of Cyclobutanones: Rapid and Asymmetric Construction of [3.3.1] Bridged Bicycles was written by Hou, Si-Hua;Yu, Xuan;Zhang, Rui;Deng, Lin;Zhang, Mengxi;Prichina, Adriana Y.;Dong, Guangbin. And the article was included in Journal of the American Chemical Society in 2020.Product Details of 98231-07-3 This article mentions the following:
Synthesis of bridged scaffolds via Type II cyclization constitutes substantial challenges due to the intrinsic ring strain accumulated in reaction transition states. Catalytic enantioselective Type II-cyclization methods are even rarer. Here, a detailed study of developing a Rh(I)-catalyzed enantioselective intramol. Type II cyclization of alkynes via C-C activation of cyclobutanones is described. This method offers a rapid approach to access a wide range of functionalized [3.3.1]-bridged bicycles along with an exocyclic olefin and an all-carbon quaternary stereocenter. Excellent enantioselectivity has been achieved using a combination of cationic rhodium(I) and DTBM-segphos. Attributed to the redox neutral and strong acid/base-free reaction conditions, high chemoselectivity has also been observed For the oxygen-tethered substrates, the reaction can proceed at room temperature In addition, partial kinetic resolution has been achieved for substrates with existing stereocenters, forging interesting chiral tricyclic scaffolds. The methylalkyne-derived substrates gave unexpected dimeric structures in good yield with excellent enantioselectivity and complete diastereoselectivity. Furthermore, the bridged bicyclic products can be diversely functionalized through simple transformations. Finally, mechanistic studies reveal a surprising reaction pathway that involves forming a metal-stabilized anti-Bredt olefin intermediate. In the experiment, the researchers used many compounds, for example, Methyl 3,3-dimethoxycyclobutanecarboxylate (cas: 98231-07-3Product Details of 98231-07-3).
Methyl 3,3-dimethoxycyclobutanecarboxylate (cas: 98231-07-3) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.Product Details of 98231-07-3
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