Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States.
J Org Chem. 2020 Aug 7;85(15):9475-9490. doi: 10.1021/acs.joc.0c01176. Epub 2020 Jul 22.
A nucleophilic retro-Claisen ring-opening of donor-acceptor cyclobutenes, formed with high stereocontrol by [3 + 1]-cycloaddition of TIPS-protected enoldiazoacetates with α-acyl sulfur ylides, has been developed. Removal of the TIPS group to form the isolable β-keto ester precedes the strain-induced ring-opening. Various amines, alcohols, thiols, and amino acid derivatives are effective nucleophiles, and their products are formed in very high yields via stoichiometric reactions. The chirality of the reactant donor-acceptor cyclobutenes is fully retained in the ring-opening reactions. The 3-acylglutaric acid products are converted to various valuable structures, including amido-diols, γ-aminobutyric acid (GABA) derivatives, and heterocycles.
已开发出一种亲核反-Claisen 环开环反应，通过 TIPS 保护的烯二唑乙酸酯与α-酰基硫叶立德的[3 + 1]-环加成，以高立体选择性形成给体-受体环丁烯。在应变诱导的开环之前，先除去 TIPS 基团以形成可分离的β-酮酯。各种胺、醇、硫醇和氨基酸衍生物是有效的亲核试剂，通过计量反应以非常高的产率形成其产物。反应物给体-受体环丁烯的手性在开环反应中得到完全保留。3-酰基戊二酸产物可转化为各种有价值的结构，包括酰胺二醇、γ-氨基丁酸（GABA）衍生物和杂环。
