Base-induced rearrangement of 1-(trimethylsilyl)allylic alcohols. Stereo- and regioselective synthesis of silyl enol ethers through lithium homoenolates
A Convenient Synthesis of Episulfides and Their Conversion into Alkenes
作者:Piotr Dybowski、Aleksandra Skowrońska
DOI:10.1055/s-1997-1329
日期:1997.10
A convenient and stereoselective synthesis of episulfides based on the reaction of readily available S-(β-oxoalkyl) thiophosphate with sodium borohydride and their conversion into alkenes is described.
α-Nitration of Ketones <i>via</i> Enol Silyl Ethers. Radical Cations as Reactive Intermediates in Thermal and Photochemical Processes
作者:Rajendra Rathore、Jay K. Kochi
DOI:10.1021/jo9515687
日期:1996.1.1
silyl ether (ESE) to TNM results in the radical ion triad [ESE(*)(+), NO(2)(*), C(NO(2))(3)(-)]. A subsequent fast homolytic coupling of the cation radical of the enol silyl ether with NO(2)(*)() leads to the alpha-nitro ketones. The use of time-resolved spectroscopy and the disparate behavior of the isomeric enol silyl ethers of alpha- and beta-tetralones as well as of 2-methylcyclohexanone strongly
A novelcatalyticsystem based on copper(I) and chiral bis(phosphine) dioxides is described. This allows the arylation of silyl enol ethers to access enolizable α-arylated ketones in good yields and enantiomeric excess up to 95%. Noncyclic ketones are amenable substrates with this method, which complements other approaches based on palladium catalysis. Optimization of the ligand structure is accomplished
Stereoselective Synthesis of Trisubstituted Vinylboronates from Ketone Enolates Triggered by 1,3‐Metalate Rearrangement of Lithium Enolates
作者:Yue Hu、Wei Sun、Tao Zhang、Nuo Xu、Jianeng Xu、Yu Lan、Chao Liu
DOI:10.1002/anie.201909235
日期:2019.10.28
unprecedented stereoselectivesynthesis of trisubstituted vinylboronates is reported to proceed by direct borylation of lithium ketone enolates under transition-metal-free conditions. The stereospecific C-O borylation of lithium enolates was triggered by a carbonyl-induced 1,3-metalate rearrangement via a C-bound boron enolate. DFT calculations and control experiments revealed that the stereoselectivity is controlled