Iron-catalyzed intermolecular [2+2] cycloadditions of unactivated alkenes
作者:Jordan M. Hoyt、Valerie A. Schmidt、Aaron M. Tondreau、Paul J. Chirik
DOI:10.1126/science.aac7440
日期:2015.8.28
synthetic chemistry. The analogous [2+2] alkene cycloaddition to synthesize cyclobutanes is kinetically accessible by photochemical methods, but the substrate scope and functional group tolerance are limited. Here, we report iron-catalyzed intermolecular [2+2] cycloaddition of unactivated alkenes and cross cycloaddition of alkenes and dienes as regio- and stereoselective routes to cyclobutanes. Through
铁充当媒人配对烯烃理论上,将正确波长的光照射到碳-碳双键上应该将它们配对成四元环丁烷环。然而,在实践中,这条路线可能被证明是挑剔和低效的,特别是如果必要的波长位于紫外线区域的深处。霍伊特等人。报道了一种铁催化剂,可以将各种简单的烯烃诱导成这样的环,而无需光激发(参见 Smith 和 Baran 的观点)。与铁协调的配体的系统优化有效地消除了替代产品的竞争途径。科学,这个问题 p。960; 另见第。925 精心优化的催化剂提供了通向四元碳环的一般途径。[另见 Smith 和 Baran 的观点] Cycloadditions,例如 [4+2] Diels-Alder 反应形成六元环,是合成化学中最强大和最广泛使用的方法之一。类似的 [2+2] 烯烃环加成反应合成环丁烷可通过光化学方法在动力学上进行,但底物范围和官能团耐受性有限。在这里,我们报告了铁催化的未活化烯烃的分子间 [2+2] 环加成
Investigations into the Mechanism of Inter- and Intramolecular Iron-Catalyzed [2 + 2] Cycloaddition of Alkenes
作者:Matthew V. Joannou、Jordan M. Hoyt、Paul J. Chirik
DOI:10.1021/jacs.0c00250
日期:2020.3.18
catalytically relevant intermediates were used to gain insight into the mechanism of both inter- and intramolecular [2+2] cycloadditionreactions. For the stereo- and regioselective [2+2] cycloaddition of 1-octene to form trans-1,2-dihexylcyclobutane, a first-order dependence on both iron complex and alkene was measured as well as an inverse dependence on N2 pressure. Both 57Fe Mössbauer and infrared spectroscopic
Kasanskii; Lukina, Doklady Akademii Nauk SSSR, 1954, vol. 94, p. 887
作者:Kasanskii、Lukina
DOI:——
日期:——
Carbon-13 NMR spectra of methylated cyclobutanes and ethyl cyclobutane-carboxylates
作者:Ernest L. Eliel、K. Michal Pietrusiewicz
DOI:10.1002/mrc.1270130308
日期:1980.3
AbstractThe 13C NMR spectra of cyclobutane and seven methylated homologs and of ethyl cyclobutanecarboxylate and five isomeric diethyl cyclobutanedicarboxylates are reported and substituent parameters for methyl groups in methylcyclobutanes are calculated. Of note is a sizeable and nearly configuration‐independent upfield shifting γ‐effect.
WANG, YEN-SEINE;CHICKOS, JAMES S., J. ORG. CHEM., 52,(1987) N 21, 4776-4781