Addition of ketone enolates to π-allylpalladlum compounds. Stereochemistry and scope of the reaction
作者:Björn Akermark、Anny Jutand
DOI:10.1016/s0022-328x(00)93458-2
日期:1981.9
Conditions have been developed for the addition of ketone enolates to π-allylpaliadium systems, A stereochemica1 study has shown that the enolate adds from the face of the π-allyl system opposite to palladium.
ZrCp2(isoprene) reacts with aliphatic aldehydes, ketones or nitriles regioselectively on C1-carbon of the isoprene moiety to give novel 2-oxa- or 2-aza-metallacycles which release alcohols or ketones respectively on hydrolysis. In contrast, ZrCH3(η1-methylallyl)Cp2, Ti(η3-methylallyl)Cp2, and [MgCH2C(CH3)=CHCH2]n reacted with acetone on the C3-carbon of the methylallyl or the isoprene unit.
Neighboring group participation in Lewis acid-promoted [3 + 4] and [3 + 5] annulations. The synthesis of oxabicyclo[3.n.1]alkan-3-ones
作者:Gary A. Molander、Kimberly O. Cameron
DOI:10.1021/ja00056a002
日期:1993.2
2-(alkoxycarbon)-m-oxabicyclo[3.n.1]alkan-3-ones can be constructed by this process in which two new carbon-carbon bonds are generated. Unusually high regioncontrol is observed, and good to excellent stereochemicalcontrol can be achieved at virtually every position on the new carbocycles. Intramolecular neighboringgroupparticipation is proposed to explain the unusually high selectivities attained in the annulation
Highly stereoselective synthesis of exocyclic alkenes via cyclialkylation
作者:Ei-ichi Negishi、Yantao Zhang、Vahid Bagheri
DOI:10.1016/s0040-4039(01)81055-8
日期:1987.1
Treatment of stereodefined ω-halo-2-iodoalkene derivatives (1), prepared viastereoselective addition reactions of alkynes, with either -BuLi (1 equiv) or -BuLi (2 equiv) can produce exocyclicalkenes whose isomeric purity is essentially 100%.