A one-pot synthesis of ibuprofene involving three consecutive steps of superbase metalation
摘要:
A one-pot reaction sequence consisting of three consecutive metalation and electrophilic substitution stages leads to 2-(4-isobutylphenyl)propanoic acid with 52% over-all yield. A crucial step is the alkylation of deprotonated p-ethyltoluene with isopropyl bromide. In general terms, sec-alkyl halides and benzyl or allyl type alkalimetal reagents undergo coupling reactions with surprising ease.
Coupling of Reformatsky Reagents with Aryl Chlorides Enabled by Ylide‐Functionalized Phosphine Ligands
作者:Zhiyong Hu、Xiao‐Jing Wei、Jens Handelmann、Ann‐Katrin Seitz、Ilja Rodstein、Viktoria H. Gessner、Lukas J. Gooßen
DOI:10.1002/anie.202016048
日期:2021.3.15
organozinc reagents with aryl electrophiles using a cyclohexyl‐YPhos ligand bearing an ortho‐tolyl‐substituent in the backbone. This highly electron‐rich, bulky ligand enables the use of arylchlorides in room temperature couplings of Reformatsky reagents. The reaction scope covers diversely functionalized arylacetic and arylpropionic acid derivatives. Aryl bromides and chlorides can be converted selectively
Role of Sterically Demanding Chiral Dirhodium Catalysts in Site-Selective C–H Functionalization of Activated Primary C–H Bonds
作者:Changming Qin、Huw M. L. Davies
DOI:10.1021/ja504797x
日期:2014.7.9
sterically demanding dirhodium tetracarboxylate catalysts on the site selectivity of C-H functionalization by means of rhodium carbene-induced C-Hinsertion is described. The established dirhodium tetraprolinate-catalyzed reactions of aryldiazoacetates cause preferential C-H functionalization of secondary C-H bonds as a result of competing steric and electronic effects. The sterically more demanding dirhodium
An unprecedented iron-catalyzed cross-coupling of primary and secondary alkyl Grignard reagents with non-activated aryl chlorides
作者:Marc C. Perry、Amber N. Gillett、Tyler C. Law
DOI:10.1016/j.tetlet.2012.06.048
日期:2012.8
The use of N-heterocyclic carbene ligands in the iron-catalyzed cross-coupling of alkyl Grignards has allowed, for the first time, coupling of non-activated, electron rich arylchlorides. Surprisingly, the tetrahydrate of FeCl2 was found to be a better pre-catalyst than anhydrous FeCl2. Primary Grignard reagents coupled in excellent yields while secondary Grignard reagents coupled in modest yields
Abstract A ligand-free nickel-catalyzed Kumada cross-coupling of aryl bromides and tert-butyl Grignardreagents led to the formation of a series of tert-butyl aryls in moderate to good yields, excellent tBu/iBu ratios, and good functional group compatibility. A radical coupling process is indicated and a mechanism with a Ni(I)-Ni(III) catalytic cycle is proposed.