Palladium-Catalyzed Isomerization of Methylenecyclopropanes in Acetic Acid
摘要:
Pd(PPh3)(4)-catalyzed isomerization of MCPs 1 in acetic acid proceeds smoothly at 80 degrees C in toluene to give the corresponding I-substituted or 1,1-disubstituted dienes 2 in good to excellent yields under mild conditions. The plausible mechanism has been disclosed on the basis of a deuterium-labeling experiment.
Palladium-Catalyzed Addition of Alcohol Pronucleophiles to Alkylidenecyclopropanes
作者:Drexel H. Camacho、Itaru Nakamura、Shinichi Saito、Yoshinori Yamamoto
DOI:10.1021/jo001428j
日期:2001.1.1
Palladium-catalyzedaddition of alcohol pronucleophiles 1 to alkylidenecyclopropane derivatives 2 afforded the corresponding allylic ethers 3 in excellent to moderate yields. Catalyst optimization indicated the Pd(PPh3)4-P(o-tolyl)3 combination as the best system among all catalysts tested. Intramolecular reaction also proceeded smoothly. A plausible mechanism for this catalytic reaction was proposed
Ring-Opening Reactions of MCPs with Sulfonamides Promoted by Metal Triflate Lewis Acids
作者:Yu Chen、Min Shi
DOI:10.1021/jo035233y
日期:2004.1.1
sulfonamides gives the corresponding pyrrolidine derivatives under the same conditions. Through deuterium-labeling experiments, we found that the reaction process is involved with the rearrangement of a cyclopropylcarbinyl cation and a nonclassic carboniumion.
Addition of Heteroaromatics to Alkylidenecyclopropanes Catalyzed by Palladium
作者:Itaru Nakamura、Amal I. Siriwardana、Shinichi Saito、Yoshinori Yamamoto
DOI:10.1021/jo0255126
日期:2002.5.1
The reaction of heteroaromatics, such as furans, thiophenes, thiazoles, and pyrroles, with alkylidenecyclopropanes proceeded smoothly in the presence of palladium catalysts, producing the corresponding alpha-allylated products in good to high yields. For example, the reaction of 3-butylpentylidenecyclopropane (1a) with 2-methylfuran (2a), ethyl 2-thiophenecarboxylate (4a), 2-isobutylthiazole (6a),
Synthesis of 5-Azaindolizine Derivatives by the Palladium-Catalyzed Intermolecular Formal [3+2] Cycloaddition of Alkylidenecyclopropanes with 1,2-Diazines
作者:Amal I. Siriwardana、Itaru Nakamura、Yoshinori Yamamoto
DOI:10.1021/jo035810i
日期:2004.4.1
The palladium-catalyzed formal [3+2] cycloaddition reaction of alkylidenecyclopropanes with 1,2-diazines proceeded smoothly to give the corresponding 5-azaindolizine derivatives in good to allowable yields. For example, in the presence of 5 mol % of Pd(PPh3)4, the reaction of 1-propylhexylidenecyclopropane with phthalazine or with pyridazine proceeded at 120 °C without solvent, and the corresponding
Synthesis of Spiro[2.2]pentanes and Spiro[2.3]hexanes Employing the Me<sub>3</sub>
Al/CH<sub>2</sub>
I<sub>2</sub>
Reagent
作者:Ilfir R. Ramazanov、Rita N. Kadikova、Tat'yana P. Zosim、Usein M. Dzhemilev、Armin de Meijere
DOI:10.1002/ejoc.201700991
日期:2017.12.22
Substituted alkylidenecyclopropanes reacted with 5 equivalents each of Me3Al and CH2I2 at room temperature in hexane to give 1-mono- and 1,1-disubstituted spiro[2.2]pentanes in high yields. Surprisingly, the same reaction with substituted alkylidenecyclopropanes in CH2Cl2 afforded exclusively 1,1-disubstituted spiro[2.3]hexanes. The transformation of 1,1-diphenylspiro[2.2]pentane into 1,1-diphenylspiro[2