Synthesis of [1.1.1]Propellanes by Cyclization of 3-Alkylidenecyclobutylidenes
摘要:
Starting from tricyclo[3.1.0.0(2,6)]hexane 5 and 1-bromobicyclo[1.1.0 ]butane 6, a series of [1.1.1]propellanes 15 and 21 has been synthesized which carry alkyl, aryl, alkenyl, and alkynyl groups. Propellane formation proceeded via 1-bromo-1-chloro-3-alkylidenecyclobutanes of type 13 and 19, which on treatment with methyllithium gave rise to the generation of carbenes 14 and 20 as short-lived intermediates. For these carbenes, the most efficient path of stabilization is obviously the intramolecular cycloaddition. Ab initio MO calculations at the Becke3LYP/6-31G* and MP2/6-31G* level of theory indicated that 3-alkylidenecyclobutylidenes 4 and 37a-d are not local energy minima but collapse to the corresponding [1.1.1]propellanes. On this basis, propellane formation should follow a carbenoid reaction path.
Synthesis of [1.1.1]Propellanes by Cyclization of 3-Alkylidenecyclobutylidenes
作者:Monika Kenndoff、Andrea Singer、Günter Szeimies
DOI:10.1002/prac.19973390141
日期:——
Starting from tricyclo[3.1.0.0(2,6)]hexane 5 and 1-bromobicyclo[1.1.0 ]butane 6, a series of [1.1.1]propellanes 15 and 21 has been synthesized which carry alkyl, aryl, alkenyl, and alkynyl groups. Propellane formation proceeded via 1-bromo-1-chloro-3-alkylidenecyclobutanes of type 13 and 19, which on treatment with methyllithium gave rise to the generation of carbenes 14 and 20 as short-lived intermediates. For these carbenes, the most efficient path of stabilization is obviously the intramolecular cycloaddition. Ab initio MO calculations at the Becke3LYP/6-31G* and MP2/6-31G* level of theory indicated that 3-alkylidenecyclobutylidenes 4 and 37a-d are not local energy minima but collapse to the corresponding [1.1.1]propellanes. On this basis, propellane formation should follow a carbenoid reaction path.
Continuous Synthesis Method for 1, 1'-Bicyclic [1.1.1]Pentane-1,3-Diethyl Ketone Compounds
申请人:JILIN ASYMCHEM LABORATORIES CO., LTD.
公开号:US20220144744A1
公开(公告)日:2022-05-12
Provided is a continuous synthesis method for 1,1′-bicyclic[1.1.1]pentane-1,3-diethyl ketone compounds. The continuous synthesis method comprises: under the irradiation of a light source, continuously conveying raw material A and raw material B to a continuous reaction device for a continuous photochemical reaction to obtain 1,1′-bicyclic[1.1.1]pentane-1,3-diethyl ketone compounds, and controlling the reaction temperature in the continuous reaction device by a temperature control device during the continuous photochemical reaction. A propellane with substituents, as a reaction raw material, is subjected to the above photochemical reaction in the continuous reaction device to reduce the probability of its slow decomposition and deterioration under the irradiation, and greatly improve the conversion rate of the reaction material and product yield.