Preparation of Organoaluminum Reagents from Propargylic Bromides and Aluminum Activated by PbCl2 and Their Regio- and Diastereoselective Addition to Carbonyl Derivatives
作者:Li-Na Guo、Hongjun Gao、Peter Mayer、Paul Knochel
DOI:10.1002/chem.201000523
日期:2010.8.23
propargylic and allenic aluminum reagents have been easily prepared by a direct insertion of aluminum into propargylic bromides in the presence of PbCl2 (1 mol %). These organoaluminum reagents react with carbonyl compounds to afford the corresponding allenic alcohols or homopropargylic alcohols in good to excellent yields with high regio‐ and diastereoselectivity.
The propargyltitanium reagents derived from 1-alkylpropyne condensed with aldehydes to give α-allenyl alcohol regioselectively, while the allenyltitanium reagents generated from 1-alky1-1-butyne derivatives gave threo-β-acetylenic alcohols with high regio- and stereoselectivities. The course of the reaction was determined by the substitution pattern of starting alkynes. The similar reactions of metallated
Highly efficient synthesis of propargyl- and allenyltitanium reagents from propargyl halides or propargyl alcohol derivatives. Practical synthesis of allenyl and homopropargyl alcohols
作者:Takashi Nakagawa、Aleksandr Kasatkin、Fumie Sato
DOI:10.1016/0040-4039(95)00514-d
日期:1995.5
Reaction of Ti(O-i-Pr)4/2 i-PrMgBr, synthetic equivalent of practical Ti(II) reagent, with propargylhalides or propargyl alcohol derivatives affords allenyl titanium compounds in excellent yields, thus providing an efficient and practical method for synthesis of both allenyl and homopropargyl alcohols by the successive treatment with aldehydes or ketones.
A CONVENIENT SYNTHESIS OF α-HYDROXYALLENES BY THE REACTION OF PROPARGYL IODIDES WITH ALDEHYDES IN THE PRESENCE OF STANNOUS HALIDE
作者:Teruaki Mukaiyama、Taira Harada
DOI:10.1246/cl.1981.621
日期:1981.5.5
In the presence of stannous halide, propargyl iodides react with aldehydes in an aprotic solvent to yield α-hydroxyallenes as major products, particularly in the cases of γ-substituted propargyl iodides, along with β-hydroxyacetylenes.
REACTION OF PROPARGYL BROMIDE AND TRIMETHYLSILYLPROPARGYL IODIDE WITH METALLIC TIN, ALUMINUM, AND ALDEHYDES OR KETONES. SELECTIVE SYNTHESIS OF β-ACETYLENE, β-TRIMETHYLSILYLACETYLENE, AND α-TRIMETHYLSILYLALLENE ALCOHOLS
β-Acetylenic and α-allenic alcohols were synthesized selectively by the reaction of aldehydes and ketones with organotin compounds prepared by treatment of propargyl bromide or trimethylsilylpropargyl iodide with metallic tin and aluminum in a suitable solvent.