103150-19-2Relevant academic research and scientific papers
Au-Catalyzed Intermolecular [2+2] Cycloadditions between Chloroalkynes and Unactivated Alkenes
Bai, Yu-Bin,Luo, Zaigang,Wang, Yuguang,Gao, Jin-Ming,Zhang, Liming
supporting information, p. 5860 - 5865 (2018/05/14)
The [2+2] cycloaddition is a versatile strategy for the synthesis of strained cyclobutenes of high synthetic value. In this study, two efficient intermolecular [2+2] cycloadditions between two different types of chloroalkynes and unactivated alkene are realized with gold catalysis. Of significance is that the reaction works with challenging monosubstituted unactivated alkenes, which is unprecedented in gold catalysis and scarcely documented in other metal-catalyzed/promoted reactions; moreover, the reaction exhibits excellent regioselectivities, which are much better than those reported in literature. With 1,2-disubstituted unactivated alkenes, the reaction is largely stereospecific. The cyclobutene products can be prepared in nearly gram scale and readily undergo further reactions including various cross-coupling reactions using the C(sp2)-Cl and/or C(sp2)-SPh bond, which in turn substantially broaden the scope of accessible cyclobutenes and enhance the synthetic utility of this bimolecular reaction.
Allylic Displacements and a Novel Ester-Ether Interchange in Fused Cyclobutanones
Hassner, Alfred,Dillon, John
, p. 3315 - 3319 (2007/10/02)
Chlorophenylcyclobutanone 11, prepared by chlorophenylketene addition to cyclohexene, reacts readily with simple and hindered carboxylic acids in a cine substitution to produce keto esters 14.The acyloxy and phenyl substituents in 14c are shown by X-ray diffraction to be cis oriented; nevertheless 14 reacts with NaOMe at 20 deg C by an unusual ester-ether interchange to produce 15 and the released carboxylate RCO2-.These reactions apparently proceed via an oxyallyl cation intermediate.The behaviors of related cyclobutanones 4, 6, and 11 with methoxide are contrasted.
