Reaction of tin enolates with substituted tricarbonylcyclohexadienyliumiron hexafluorophosphate electrophiles: diastereoselective synthesis of (±)-trichodiene
作者:Anthony J. Pearson、Michael K. O'Brien
DOI:10.1039/c39870001445
日期:——
A number of tinenolates react cleanly with tricarbonylcyclohexadienyliumiron cations, in cases where the use of lithium enolates or silyl enol ethers is problematic; this new carbon–carbon bond-forming reaction allows diastereoselective construction of proximate quaternary centres and provides a key step in a short synthesis of (±)-trichodiene.
Simple Synthesis of α-Hydroxyamino Carbonyl Compounds: New Scope of the Nitroso Aldol Reaction
作者:Norie Momiyama、Hisashi Yamamoto
DOI:10.1021/ol026443k
日期:2002.10.1
[reaction: see text] The reaction of nitrosocompounds with enolates, "the nitroso aldol reaction", occurs in high yield to generate alpha-hydroxyamino carbonyl compounds. Yields range from 42% to 98% with N-selectivity >99:1 from commercially available aromatic or aliphaticnitrosocompounds and a variety of alkali metal or tin enolates.
Regioselectivity in organo-transition-metal chemistry. A remarkable steric effect in π-allyl palladium chemistry
作者:Ehud Keinan、Mahendra Sahai
DOI:10.1039/c39840000648
日期:——
The regioselectivity of the palladium catalysed allylic substitution by several representative nucleophiles was found to be highly dependent on very small steric differences that exist at the two ends of the allylic system: attack by stabilized nucleophiles occurred at the less hindered position while PhZnCl led to substitution at the more hindered position.
Enantioselective Alkylations of Tributyltin Enolates Catalyzed by Cr(salen)Cl: Access to Enantiomerically Enriched All-Carbon Quaternary Centers
作者:Abigail G. Doyle、Eric N. Jacobsen
DOI:10.1021/ja043601p
日期:2005.1.1
The catalytic asymmetric alpha-alkylation of tributyltinenolates with a range of primary alkyl halides is catalyzed by a chiral Cr(salen) complex. The reaction constitutes the first transition-metal-catalyzed system for alpha-alkylation of carbonyl substrates with this important class of electrophiles, providing access to five-, six-, and seven-membered ring ketone products bearing alpha-quaternary