16930-95-3Relevant articles and documents
Ruthenium-catalyzed [2+2] cycloaddition reactions of a 2-oxa-3- azabicyclo[2.2.1]hept-5-ene with unsymmetrical alkynes
Durham, Robin,Mandel, Jeremie,Blanchard, Nicolas,Tam, William
, p. 1494 - 1505 (2011)
Ruthenium-catalyzed [2+2] cycloaddition reactions of a 2-oxa-3- azabicyclo[2.2.1]hept-5-ene with unsymmetrical alkynes were investigated. Yields of up to 90% were obtained though regioselectivity was modest. Select cycloadducts could be separated and used to access a highly functionalized [3.2.0] bicyclic structure through reductive cleavage of the N-O bond. These ring-opened products displayed a chemical exchange phenomenon in 1D carbon NMR and required characterization by 2D NMR techniques.
Phosphine-Catalyzed Intermolecular Dienylation of Alkynoate with para-Quinone Methides
Song, Zefeng,Wang, Weijia,Liu, Zhixin,Lu, Yue,Wang, De
supporting information, p. 8590 - 8599 (2021/07/20)
An interesting remote I-C 1,6-Addition and an isomerization cascade reaction for phosphine-catalyzed activated alkynes have been disclosed. The products featuring a functional diene and a 1,1-diaryl methyl motif have been obtained in moderate to good yields (30-86%) by applying para-quinone methides (p-QMs) and I-substituted alkynoate with tributylphosphine (PnBu3) catalysis, along with high regioselectivity and stereoselectivity (dr > 20:1). The wide scope of compatible substrates (35 examples), such as indolyl, oxindolyl, ester, and cinnamyl, expand the utility of this methodology. A plausible mechanism and some applications of it have also been presented.
Development of Gold-catalyzed [4+1] and [2+2+1]/[4+2] Annulations between Propiolate Derivatives and Isoxazoles
Sahani, Rajkumar Lalji,Liu, Rai-Shung
supporting information, p. 1026 - 1030 (2017/01/18)
Two new gold-catalyzed annulations of isoxazoles with propiolates have been developed. Most isoxazoles follow an initial O attack on the alkyne to afford a [4+1] annulation product. This process results in a remarkable alkyne cleavage of initial propiolates. Unsubstituted isoxazoles proceed through an N attack step to yield formal [2+2+1]/[4+2] annulation products. These two annulation products arise initially from two seven-membered heterocyclic intermediates, which then lead to products.
Gold-catalyzed formal [4π+2π]-cycloadditions of tert-butyl propiolates with aldehydes and ketones to form 4H-1,3-dioxine derivatives
Karad, Somnath Narayan,Chung, Wei-Kang,Liu, Rai-Shung
supporting information, p. 13004 - 13007 (2015/08/06)
Gold-catalyzed formal hetero-[4π+2π] cycloadditions of tert-butyl propiolates with carbonyl compounds proceeded efficiently to yield 4H-1,3-dioxine derivatives over a wide scope of substrates. With acetone as a promoter, gold-catalyzed cycloadditions of these propiolate derivatives with enol ethers led to the formation of atypical [4+2]-cycloadducts with skeletal rearrangement.
