Iron Catalyzed Double Bond Isomerization: Evidence for an Fe
<sup>I</sup>
/Fe
<sup>III</sup>
Catalytic Cycle
作者:Callum R. Woof、Derek J. Durand、Natalie Fey、Emma Richards、Ruth L. Webster
DOI:10.1002/chem.202004980
日期:2021.4
Density Functional Theory (DFT) and Electron Paramagnetic Resonance (EPR) spectroscopy. The data obtained support a pre‐catalyst activation step that gives access to an η2‐coordinated alkene FeI complex, followed by oxidative addition of the alkene to give an FeIII intermediate, which then undergoes reductive elimination to allow release of the isomerization product.
据报道,铁催化的烯烃异构化使用铁(II) β-二酮亚胺预催化剂。该反应在催化量的氢化物源(例如频哪醇硼烷(HBpin)或氨硼烷(H 3 N·BH 3))下进行。已研究了与烯丙基芳烃和脂肪族烯烃的反应性。通过多种手段研究了催化机理,包括氘化研究、密度泛函理论(DFT)和电子顺磁共振(EPR)光谱。获得的数据支持预催化剂活化步骤,该步骤提供了 η 2配位烯烃 Fe I络合物,然后通过氧化加成烯烃得到 Fe III中间体,然后进行还原消除以释放异构化产物。
Stereoselective aldol condensations of organotin reagents with aldehydes
作者:Sharada S. Labadie、J.K. Stille
DOI:10.1016/0040-4020(84)80016-2
日期:1984.1
reaction requiring isomerization of the C-Sn to the O-Sn enolate. The Pd catalyzed condensation of cyanomethyltributyltin with reactive aldehydes, such as nitrobenzaldehydes, took place at ambient temperatures in polar solvents to give high yields of condensation products. No reaction occurred with aldehydes such as benzaldehyde. Only low stereoselectivity (10-34% ee) was observed when (-) DIOP or (-)BPPM
Phosphate mediated biomimetic synthesis of tetrahydroisoquinoline alkaloids
作者:Thomas Pesnot、Markus C. Gershater、John M. Ward、Helen C. Hailes
DOI:10.1039/c0cc05282e
日期:——
A one-potsynthesis of tetrahydroisoquinoline alkaloids in a phosphate buffer has been achieved, and a reaction mechanism proposed. The utilisation of mild reaction conditions readily afforded a range of isoquinolines, including norcoclaurine.
Intermediates in the ene reactions of singlet oxygen and N-phenyl-1,2,4-triazoline-3,5-dione with olefins
作者:M. Orfanopoulos、I. Smonou、Christopher S. Foote
DOI:10.1021/ja00165a053
日期:1990.4
The reaction between singlet oxygen and cis- and trans-2-butene-1,1,1-d 3 has been studied. The product isotope effects (k H /k D ) were found to be 1.38 and 1.25, respectively. Similarly, N-phenyl-1,2,4-triazoline-3,5-dione (PTAD) reacts readily with these substrates and shows isotope effects that are larger (5.36, 1.29) but in the same direction. 2-Methyl-1-propene-3,3,3-d 3 is unreactive with singlet
Facile One‐Pot Synthesis of Polysubstituted Pyridinium Salts by Annulation of Enamines with Alkynes
作者:Seokwoo Lee、Hanbin Yoo、Soojun Park、Ran Yoon、Sanghee Kim
DOI:10.1002/chem.202300059
日期:——
An efficient and facilesynthesis of highly substituted pyridinium salts through annulation of enamines with alkynes is reported. The keys to this advancement are: 1) one-pot, mild reaction conditions; 2) broad substrate scope; and 3) selective 6-endo-dig cyclization.