Direct Access to Monoprotected Homoallylic 1,2-Diols via Dual Chromium/Photoredox Catalysis
作者:Felix Schäfers、Linda Quach、J. Luca Schwarz、Mar Saladrigas、Constantin G. Daniliuc、Frank Glorius
DOI:10.1021/acscatal.0c03697
日期:2020.10.16
Herein, we present a dual catalytic strategy to efficiently obtain monoprotected homoallylic 1,2-diols by coupling abundant aldehydes with simple (silyl) enol ethers, thus providing direct access to this important motif without the (super) stoichiometric use of prefunctionalized metal-allyl species. The modularity of our approach is shown by the introduction of several silyl- and alkyl-based protecting
Synthesis of (+)-Discodermolide by Catalytic Stereoselective Borylation Reactions
作者:Zhiyong Yu、Robert J. Ely、James P. Morken
DOI:10.1002/anie.201405455
日期:2014.9.1
1990 and, to this day, remains a compelling synthesis target. Not only does the compound possess fascinating biological activity, but it also presents an opportunity to test current methods for chemical synthesis and provides an inspiration for new reaction development. A new synthesis of discodermolide employs a previously undisclosed stereoselectivecatalytic diene hydroboration and also establishes
New Tetraphosphorus Ligands for Highly Linear Selective Hydroformylation of Allyl and Vinyl Derivatives
作者:Chaoxian Cai、Shichao Yu、Bonan Cao、Xumu Zhang
DOI:10.1002/chem.201201396
日期:2012.8.6
New tetraphosphorusligands have been developed and applied in the rhodium‐catalyzedregioselectivehydroformylation of a variety of functionalized allyl and vinyl derivatives. Remarkably high linear selectivity was obtained by these tetraphosphorusligands. The ligand that bears strong electron‐withdrawing 2,4‐difluorophenyl groups is the most effective one in affording linear aldehydes. The Rh/tetraphosphorus
catalysts for this process. The reaction allows the synthesis of a wide variety of cyclic and acyclic alkenyl nonaflates 3 in good to excellent yields. For E/Z isomeric alkenes the configuration of the double bond is essentially retained. Remarkably, enolates derived from methyl ketones also provide C-sulfonylation products 4 as a side product; the desired alkenyl nonaflates 3l and 3m could, however, be prepared
Crossed aldolreactionbetween aromatic aldehydes having an electron-withdrawing group and trimethylsilylenolates generated from several aldehydes proceeded smoothly in dry or water-containing DMF...