Synthesis of Silylated Cyclobutanone and Cyclobutene Derivatives Involving 1,4‐Addition of Zinc‐Based Silicon Nucleophiles
作者:Ming Cui、Martin Oestreich
DOI:10.1002/chem.202102993
日期:2021.11.22
intermediate metal enolate can be trapped as an enol phosphate and further reacted with Grignard reagents in Kumada cross-coupling reactions. By this, a range of silylated cyclobutanone and cyclobutenederivatives becomes accessible.
Enantioselective Synthesis of 3‐Substituted Cyclobutenes by Catalytic Conjugate Addition/Trapping Strategies
作者:Changxu Zhong、Yingchao Huang、Haocheng Zhang、Qiang Zhou、Yu Liu、Ping Lu
DOI:10.1002/anie.201913825
日期:2020.2.10
A copper-catalyzed tandem process to generate chiral cyclobutene derivatives has been developed. It is based on an enantioselective conjugate addition or reduction of a cyclobutenone and sequential trapping with a chlorophosphate in a one-pot process. These phosphates are stable under mildly acidic conditions and serve as good electrophiles in Negishi coupling reactions.
THE SILA-PUMMERER REARRANGEMENT OF 1-ALKYL-3-PHENYLSULFINYL-3-TRIMETHYLSILYLCYCLOBUTANOLS. A NEW METHOD FOR THE PREPARATION OF 3-ALKYL-2-CYCLOBUTENONES
3-Alkyl-2-cyclobutenones were produced by the sila-Pummerer rearrangement of 1-acetoxy-1-alkyl-3-phenylsulfinyl-3-trimethylsilylcyclobutanes followed by hydrolysis. β-Phenylthio-α,β-and β,γ-unsaturated ketones were major products when the corresponding cyclobutanols were employed.
Cross-Coupling of Cyclobutenone <i>N</i>-Tosylhydrazones with Organohalides: Access to Conjugated Enynes and Enallenes via a Strained Allylpalladium Intermediate
palladium-catalyzed cross-couplingreaction of cyclobutenone N-tosylhadrazones with organohalides is disclosed. The protocol involves the generation of a strained allylpalladium intermediate from readily available starting materials through palladium carbene migratory insertion, which undergoes electrocyclic ring opening and β-hydride elimination for the production of conjugated enynes and enallenes
Nickel‐Catalyzed Tunable Enantioconvergence and Kinetic Resolution in the Coupling of Tertiary Cyclobutenols with Arylboroxines
作者:Xufei Yan、Yulei Zhu、Ying Xia
DOI:10.1002/anie.202304462
日期:2023.6.19
enantioconvergent or a kinetic resolution step was used in the reaction of tertiary cyclobutenols with arylboroxines under a Ni/modified SPINOL catalytic system. This reaction allows the direct use of free hydroxyl groups as leaving groups while the strained ring remains untouched and provides enantioenriched cyclobutenes having a tertiary hydroxyl or an all-carbon quaternary stereocenter.