The highly stereoselective allylicalkylation of Morita–Baylis–Hillman carbonates with β-ketoesters catalysed by β-ICD is described. The corresponding products containing two adjacent quaternary and tertiary carbon centers were obtained in good yields with high diastereoselectivity (up to 10 : 1 dr) and enantioselectivity (up to 95% ee).
the directly dehydrative cross-coupling of allylicalcohols with terminal alkynes was developed. This calcium salt cocatalyst facilitates the oxidative addition of the palladium catalyst (1 mol %) to the C-OH bond. Then, the in situ-generated hydroxide ion deprotonates the terminal alkynes to promote the formation of the allylalkynylpalladium intermediate, liberating water as the only byproduct. This
Stereoselective synthesis of substituted 1,2-annulated sugars by domino double-Michael addition reaction
作者:Kadigachalam Parasuraman、Ande Chennaiah、Sateesh Dubbu、A.K. Ibrahim Sheriff、Yashwant D. Vankar
DOI:10.1016/j.carres.2019.03.007
日期:2019.5
A simple, highly stereoselective one-pot methodology for the synthesis of novel 1,2-annulated sugars comprising of oxa-oxa and oxa-carbasugar fused skeletons from 2-nitrogalactal and a sugar-derived enone, obtained from 2-formylgalactal, promoted by KOtBu and CH3ONa respectively is described. Both processes rely on a domino double-Michael additionreaction resulting in the formation of three stereocenters
Herein, we report an atom-economical and environmentally benign approach for P–Cbond construction via C–OH/P–H dehydrative cross-coupling reaction. This reaction was carried out under metal-free conditions, proceeds in the absence of any solvent and delivered allylic phosphorus compounds in high yields with wide functional group tolerance.
A cascade synthesis of<i>S</i>-allyl benzoylcarbamothioates<i>via</i>Mumm-type rearrangement
作者:Anjali Dahiya、Wajid Ali、Tipu Alam、Bhisma K. Patel
DOI:10.1039/c8ob02293c
日期:——
A cascade synthesis ofS-allyl benzoylcarbamothioates has been achieved from Morita Baylis Hillman alcohols and aroyl isothiocyanatesviaMumm-type rearrangement.