A Heteroleptic Dirhodium Catalyst for Asymmetric Cyclopropanation with α‐Stannyl α‐Diazoacetate. “Stereoretentive” Stille Coupling with Formation of Chiral Quarternary Carbon Centers
作者:Fabio P. Caló、Alois Fürstner
DOI:10.1002/anie.202004377
日期:2020.8.10
The heteroleptic dirhodium paddlewheel catalyst 7 with a chiral carboxylate/acetamidate ligand sphere is uniquely effective in asymmetric [2+1] cycloadditions with α‐diazo‐α‐trimethylstannyl (silyl, germyl) acetate. Originally discovered as a trace impurity in a sample of the homoleptic parent complex [Rh2((R )‐TPCP)4] (5 ), it is shown that the protic acetamidate ligand is quintessential for rendering
Rh<sub>2</sub>(<i>R</i>-TPCP)<sub>4</sub>-Catalyzed Enantioselective [3+2]-Cycloaddition between Nitrones and Vinyldiazoacetates
作者:Changming Qin、Huw M. L. Davies
DOI:10.1021/ja4069003
日期:2013.10.2
Rhodium-catalyzed reaction of vinyldiazoacetates with nitrones results in a formal [3+2]-cycloaddition to generate 2,5-dihydroisoxazoles with high levels of asymmetricinduction. The cascade reaction begins with a vinylogous addition event, followed by an iminium addition ring-closure/hydride migration/alkene isomerization cascade. Dirhodium tetrakis(triarylcyclopropanecarboxylates) are the optimum
Dirhodium Tetraprolinate-Catalyzed Asymmetric Cyclopropanations with High Turnover Numbers
作者:Huw M. L. Davies、Chandrasekar Venkataramani
DOI:10.1021/ol034002a
日期:2003.5.1
graphicThe bridged dirhodium tetraprolinate Rh-2(S-biTISP)(2) (2) catalyzes the asymmetric cyclopropanation reaction between methyl phenyldiazoacetate and styrene at room temperature with high turnover number (92 000) and turnover frequency (4000 per h).
From Serendipity to Rational Design: Heteroleptic Dirhodium Amidate Complexes for Diastereodivergent Asymmetric Cyclopropanation
stannylated cyclopropanes to be made selectively and in excellent optical purity, this transformation also marks a rare case of diastereodivergent asymmetric catalysis. The products are amenable to stereospecific cross coupling with aryl halides or alkenyl triflates; these transformations appear to be the first examples of the formation of stereogenic quaternary carbon centers by the Stille reaction; carbonylative