Use of Strain-Release for the Diastereoselective Construction of Quaternary Carbon Centers
作者:Tobias Pinkert、Mowpriya Das、Malte L. Schrader、Frank Glorius
DOI:10.1021/jacs.1c03492
日期:2021.5.26
formation of quaternary carbon centers with excellent diastereoselectivity via a strain-release protocol. An organometallic species is generated by Cp*Rh(III)-catalyzed C–H activation, which is then coupled with strained bicyclobutanes (BCBs) and a prochiral carbon electrophile in a three-component reaction. This work illustrates a rare example of BCBs in transition metal catalysis and demonstrates their
Palladium-Catalyzed Oxidative Ethoxycarbonylation of Aromatic C−H Bond with Diethyl Azodicarboxylate
作者:Wing-Yiu Yu、Wing Nga Sit、Kin-Man Lai、Zhongyuan Zhou、Albert S. C. Chan
DOI:10.1021/ja710555g
日期:2008.3.1
(DEAD) together with Oxone or K2S2O8. Substrates such as 2-arylpyridines, pyrrolidinone, acetylindoline, quinoline, and oximes were ethoxycarbonylated with excellent chemo- and regioselectivities. The catalytic reaction is probably initiated by chelation-assisted cyclopalladation of the ortho-C−H bond. Preliminary studies suggested that reactive ethoxyacyl radicals generated from thermal decomposition
Asymmetric reduction of oxime ethers. Distinction of anti and syn isomers leading to enantiomeric amines.
作者:Yoji Sakito、Yukio Yoneyoshi、Gohfu Suzukamo
DOI:10.1016/s0040-4039(00)80059-3
日期:1988.1
Anti and syn ketoxime ethers were reduced with a chiral reducing agent prepared from (−)-norephedrine and 2 eq of BH3 to give S and R amines respectively in up to 92% ee. The preferred absolute configuration of the amine was depended on the geometry of the oxime ether.
A palladium-catalyzed ortho-directed alkylation of O-methyl ketoximes that proceeds through a regioselective ring-opening reaction of epoxides has been demonstrated. This C(sp2)–H activation/alkylation protocol was carried out in pivalic acid/1,1,1,3,3,3-hexafluoro-2-propanol (PivOH/HFIP, 2:8) as the solvent and was applied to various O-methyl ketoximes that contain either electron-donating or electron-withdrawing
Rhodium-Catalyzed Direct C-H Phosphorylation of (Hetero)arenes Suitable for Late-Stage Functionalization
作者:Minsik Min、Dahye Kang、Sungwoo Jung、Sungwoo Hong
DOI:10.1002/adsc.201600014
日期:2016.4.14
Efficient rhodium‐catalyzed direct C–H phosphorylation of (hetero)arenes was developed. Various directing groups and a wide range of substrates, including heterocycles, can be utilized in this C–H phosphorylation process, allowing for the rapid installation of the phosphonate group into medicinally and biologically important privileged scaffolds. The efficient and straightforward method could serve