WebChiral allylsilane (R)-1e exhibited 29Si chemical shift at 17.2 ppm in CD 2 Cl 2 solution at -50 oC (Figure S5). Upon addition of HNTf 2 (1 equiv) to the solution of (R)-1e in CD 2 Cl 2, the 29Si signal was downfield-shifted to +49.0 ppm at -50 oC (Figure S4). 29Si NMR spectra of tetracoordinate silyl triflimides having Si-N bonds with C n Si 3 ... WebSep 1, 2005 · Woerpel and coworkers have previously described a kinetic resolution in a double asymmetric [3+2] annulation reaction of a racemic allylsilane and a chiral auxiliary-bearing α-keto ester to prepare highly-substituted tetrahydrofurans as single enantiomers. 21 Our methodology is complementary in that it takes advantage of the stereochemistry ...

Leighton’s Chiral Allylation Reagents

WebDec 15, 2011 · Three-in-one: The nickel-catalyzed asymmetric three-component coupling of 1,3-dienes, aldehydes, and a silylborane in the presence of a chiral phosphoroamidite ligand has been realized. The reaction proceeds by σ-bond metathesis of an oxanickelacycle intermediate with the silylborane to afford the corresponding α-chiral … WebOct 1, 2009 · Distribution of these products can be controlled by the fine optimization of the catalyst. In that case, the process will be asymmetric transformation controlled by the chiral catalyst even when racemic allylsilanes are used. 3 1 Scheme Generation of four possible isomers from chiral allylsilane. fly to batemans bay

NMR Study on Ligand Exchange Reaction between a …

Webdeveloped chiral auxiliary based on the cyclohexane-1,2-diamine scaffold successfully allylated a broad range of aldehydes highly enantioselectively.2 Ph N H NHAc + Ph NHNHAc CH 2 ... chiral allylsilane reagent to a structurally diverse array N O Si H3C CH3 CH2 Cl R1 N R2 NHBz + 1 CHCl R2 NHNHBz 3 24 h Ph CH2 H3C NHNHBz 86%; 90% … WebApr 9, 2016 · The zinc-Brook rearrangement of enantiomerically enriched α-hydroxy allylsilane produces a chiral allylzinc intermediate, which reacts with retention of configuration in the presence of an electrophile. Two remarkable features of this transformation are the stereochemical outcome during the formation of the allylzinc … WebThree-in-one: The nickel-catalyzed asymmetric three-component coupling of 1,3-dienes, aldehydes, and a silylborane in the presence of a chiral phosphoroamidite ligand has been realized. The reaction proceeds by σ-bond metathesis of an oxanickelacycle intermediate with the silylborane to afford the corresponding α-chiral allylsilane derivative ... greenpoint subdivision