The syn addition of alkylcopper compounds to various alkynes HCC(CH2)2Z (n = 2, 3, Z = X, NEt2, SEt, OR) shows a regio-selectivity dependant on various factors, the major factors being the nature of the function and the solvent. The vinylcopper derivatives thus obtained have been carboxylated, iodinated and alkylated.
Stereoselective Dichlorination of Allylic Alcohol Derivatives to Access Key Stereochemical Arrays of the Chlorosulfolipids
作者:Grant M. Shibuya、Jacob S. Kanady、Christopher D. Vanderwal
DOI:10.1021/ja804167v
日期:2008.9.17
Dichlorination of (Z)-allylic trichloroacetates efficiently and stereoselectively generates the syn,syn hydroxydichloride stereotriad that is prevalent in the understudied polychlorinated sulfolipid class of natural products. Further, the dichlorination of a (Z)-allylic chlorohydrin affords with high selectivity a stereotetrad present in one of the chlorosulfolipids.
Monosubstituted 3,3‐Difluorocyclopropenes as Bench‐Stable Reagents: Scope and Limitations
作者:Pavel S. Nosik、Mykola O. Pashko、Andrii S. Poturai、Denys A. Kvasha、Alexander E. Pashenko、Alexander B. Rozhenko、Sergiy Suikov、Dmitriy M. Volochnyuk、Sergey V. Ryabukhin、Yurii L. Yagupolskii
DOI:10.1002/ejoc.202100921
日期:2021.12.21
A protocol for the synthesis of gem-difluorocyclopropenes was developed, based on Ruppert-Prakash reagent slow addition. The empiric observations allow to predict whether the compound could be stocked neat, as a solution, or only used after generation in situ.
Stereoselective formation of 1,2-diiodoalkenes and their application in the stereoselective synthesis of highly functionalised alkenes via Suzuki and Stille coupling reactions
作者:Nadine Hénaff、Andrew Whiting
DOI:10.1039/a906832e
日期:——
Treatment of an alkyne with iodine monochloride and sodium iodide at room temperature results in the formation of the thermodynamic (E)-diiodoalkene. The corresponding (Z)-diiodoalkene can also be produced, by treatment of the alkyne with iodine monochloride at −78 °C in the presence of tetraethylammonium iodide. Such 1,2-diiodoalkenes are useful for the synthesis of more functionalised alkenes by using either Stille or Suzuki cross-coupling protocols.
A Unified Synthetic Approach to Polyketides Having Both Skeletal and Stereochemical Diversity
作者:Shiying Shang、Hayato Iwadare、Daniel E. Macks、Lisa M. Ambrosini、Derek S. Tan
DOI:10.1021/ol070405p
日期:2007.5.1
developed to provide both skeletal and stereochemical diversity. Each synthetic intermediate is also a desired polyketide fragment and no protecting group manipulations are required. A first-generation synthesis provides a 74-membered polyketide library comprising six different skeletal classes, each in one to five steps from propargylic alcohol precursors. A study of epoxyol opening reactions revealed