A highly efficient addition of allylic bromides to carbonyl compounds promoted by Cp2TiCl2(cat.)/Zn system
作者:Yu Ding、Gang Zhao
DOI:10.1016/s0040-4039(00)74734-4
日期:1992.12
Aldehydes or ketones reacted with allylic bromides in the presence of Cp2TiCl2(cat.)/Zn system at room temperature to give homo-allylic alcohols in high yields.
Homoallylic (but-3-enylic) alcohols have been prepared in good yields
by reductive allylation of aldehydes in water with various allylic
chlorides in the presence of tin(II) chloride and potassium
iodide. The Barbier type reaction with prop-2-ynyl chloride is also
achieved under the same conditions.
Regioselective allylation and propargylation were achieved using acylsilanes as electrophiles and this methodology was applied to the synthesis of PGE3 and F3α methylester.
The Reaction of some Carbonyl and Thiocarbonyl Compounds with Prenyl- and Crotyllithium in Tetrahydrofuran Solution
作者:V. Rautenstrauch
DOI:10.1002/hlca.19740570226
日期:——
(1) and cis-crotyllithium (Z-but-2-enyl-lithium) (2) in tetrahydrofuran solution, prepared according to the method of Eisch & Jacobs, react with carbonylcompounds to give the branched alcoholates with moderate to high selectivity, unless access to the carbonyl group is strongly hindered (see the Table). Adamantanethione (12) reacts with 1 to give the unbranched thiolate.
A Highly Atom Efficient, Solvent Promoted Addition of Tetraallylic, Tetraallenic, and Tetrapropargylic Stannanes to Carbonyl Compounds
作者:Adam McCluskey、I. Wayan Muderawan、Muntari、David J. Young
DOI:10.1021/jo015904x
日期:2001.11.1
Tetraallylic, tetraallenic, and tetrapropargylic stannanes (0.25 equiv) react with aldehydes in methanol to provide unsaturated alcohols in good to excellent yields (56-99%). These reactions proceed exclusively with allylic rearrangement for tetra(2-butenyl)tin 2b and tetra(1,2-butadienyl)tin 16c and predominantly with allylic rearrangement for tetrapropadienyltin 16a and tetra(2-butynyl)tin 6e. Allylation. reactions also proceeded smoothly with reactive ketones such as ethyl pyruvate (9a) and cyclohexanone (9b). The corresponding TFA-catalyzed reactions of dimethyl acetals 4d and 4e are regiospecific with allylic rearrangement.