Chelation and Nonchelation Control in the [3 + 4] and [3 + 5] Annulation Reactions of Benzyloxy-Substituted Dicarbonyl Electrophiles with Bis(trimethylsilyl) Enol Ethers
Chelation and Nonchelation Control in the [3 + 4] and [3 + 5] Annulation Reactions of Benzyloxy-Substituted Dicarbonyl Electrophiles with Bis(trimethylsilyl) Enol Ethers
Alkyl vinyl ketones and acrylic esters were hydroacylated with organotetracarbonylferrates to the corresponding 1,4-diketones and 4-oxo carboxylic acid derivatives in good yield in dipolar aprotic solvents such as N,N-dimethylacetamide. Addition of 18-crown-6 improved the yield. cis-Jasmone and γ-jasmolactone were synthesized by use of these reactions.
Ruthenium-Catalyzed Three-Component Coupling via Hydrative Conjugate Addition of Alkynes to Alkenes: One-Pot Synthesis of 1,4-Dicarbonyl Compounds
作者:Yiyun Chen、Sung Hwan Park、Chung Whan Lee、Chulbom Lee
DOI:10.1002/asia.201100266
日期:2011.8.1
A catalytic three‐way rendezvous: Terminal alkynes undergo metal vinylidene formation, anti‐Markovnikov hydration to give a metal acyl complex, and conjugate addition to produce synthetically useful 1,4‐dicarbonyl compounds under ruthenium catalysis. This one‐pot three‐component coupling reaction is a useful platform for further exploration in alkyne functionalization.
Element Effect Revisited. Variable and Inverse Element Effect in the S<sub>N</sub>Ar Reaction of Picryl Halide and 2,4-Dimethoxyaniline
作者:Naoki Sugiyama、Jun-ichi Hayami
DOI:10.1246/cl.1999.691
日期:1999.7
made of the SNAr reaction of picrylhalides (PicX, X = F, Cl) with 2,4-dimethoxyaniline in organic solvents. The element effect, kΨPicF/kΨPicCl, was found to be well-known large value at high [DMA], however, diminished continuously as the decrease of [DMA], and an inverse element effect was observed in CH3CN. Variable/inverse element effect has not been suggested for SNAr reaction and clearly shows