strategy for the synthesis of unsymmetrically disubstituted tetraphenylenes from 2-acetylbiphenylene has been developed via ruthenium-catalyzedC–Hfunctionalization. Four reactions, including alkenylation–cyclization, alkenylation, alkylation, and amidation, were achieved. The reactions provide easy access to a variety of unsymmetrically disubstituted tetraphenylene derivatives, which could accelerate research
Synthesis of 1-Benzyl-, 1-Alkoxyl-, and 1-Aminoisoquinolines via Rhodium(III)-Catalyzed Aryl C–H Activation and Alkyne Annulation
作者:Yiming Zhou、Ruimao Hua
DOI:10.1021/acs.joc.1c00786
日期:2021.7.2
(DGauto)-assisted, rhodium(III)-catalyzed aryl C–H activation and annulation with internal alkynes were developed. The reactions affording 1-benzylisoquinolines involve a cascade oximation of diarylacetylenes with hydroxylamine, forming aryl benzyl ketone oxime, and oxime-assisted rhodium(III)-catalyzed aryl C–H activation and followed annulation with another molecule of diarylacetylene in a one-pot manner
arene ring of arylglyoxals. A possible mechanism involving Fe(III)-promoted formation of a vinyl cation from arylglyoxal and alkyne, electrophilic addition of the vinyl cation to the ipso carbon of the aryl group to give a spiral intermediate, and then migration of the keto carbon to the ortho carbon was proposed as key steps and verified using quantum mechanics.
A practical and atom-economic protocol for the stereoselective preparation of various 1,4- and 1,3-diene skeletons through iridium-catalyzed directed olefinic C–H allylation and alkenylation of NH-Ts acrylamides in water was developed. This reaction tolerated a wide scope of substrates under simple reaction conditions and enabled successful gram-scale preparation. Furthermore, an asymmetric variant
Rhodium-Catalyzed Oxidative C-H Activation/Cyclization for the Synthesis of Phosphaisocoumarins and Phosphorous 2-Pyrones
作者:Youngchul Park、Jungmin Seo、Sangjune Park、Eun Jeong Yoo、Phil Ho Lee
DOI:10.1002/chem.201302652
日期:2013.11.25
Rhodium‐catalyzed cyclization of phosphinic acids and phosphonic monoesters with alkynes has been developed. The oxidative annulation proceeds with complete conversion of phosphinic acid derivatives and allowed the atom‐economic preparation of useful phosphaisocoumarins with high yield and selectivity. The reaction is tolerant of extensive substitution on the phosphinic acid, phosphonic monoester and alkyne, including