Reactions and characterization of allylic and related zirconium reagents (allenic and γ-alkoxyallylic zirconiums) generated by treatment of allylic and/or propargylic ethers with a zirconocene-butene complex (“Cp2Zr”) are described.
Hydroboration of mono-substituted allenes: A general synthetic route to the higher crotylboranes and anti-3-alkyl/aryl-4-hydroxy-1-alkenes
作者:Gowriswari Narla、Herbert C. Brown
DOI:10.1016/s0040-4039(96)02255-1
日期:1997.1
Hydroboration of mono-substituted allenes with Chx2BH at 0 °C leads to the corresponding (E)-substituted allylboranes, known as higher crotylboranes, exclusively. These higher crotylboranes react with aldehydes, and on oxidation, provide the corresponding anti-3-alkyl/aryl-4-hydroxy-1-alkenes in high diastereomeric excess. By changing the hydroborating reagent to dIpc2BH, synthesis of the corresponding
Highly Regioselective and Stereoselective Allylation of Aldehydes via Palladium-Catalyzed in Situ Hydrostannylation of Allenes
作者:Hao-Ming Chang、Chien-Hong Cheng
DOI:10.1021/ol0064563
日期:2000.11.1
regio- and stereoselective allylation of aldehydes by allenes proceeds smoothly in aqueous/organic media in the presence of PdCl(2)(PPh(3))(2), HCl, and SnCl(2). The reaction likely occurs via hydrostannylation of allenes and allylation of aldehydes by the in situ generated allyltrichlorotins to afford the final products.
Stereoselective Synthesis of γ-Substituted (<i>Z</i>)-Allylic Boranes via Kinetically Controlled Hydroboration of Allenes with 10-TMS-9-borabicyclo[3.3.2]decane
作者:Jeremy Kister、Amy C. DeBaillie、Ricardo Lira、William R. Roush
DOI:10.1021/ja905494c
日期:2009.10.14
Kineticallycontrolled hydroboration of allenes 8 and 14a-d with the readily accessible Soderquist borane 7, which is generated in situ from borohydride 6, constitutes a convenient and preparatively useful method for synthesis of (Z)-gamma-(substituted)allylboranes 9 and 15a-d. These allylboranes undergo highly diastereo- (> or = 90: 10) and enantioselective (typically 89-96% e.e.) allylboration reactions