Development of a Cross‐Conjugated Vinylogous [4+2] Anionic Annulation and Application to the Total Synthesis of Natural Antibiotic (±)‐ABX
作者:Jing‐Kai Huang、Kak‐Shan Shia
DOI:10.1002/anie.201914657
日期:2020.4.16
vinylogous [4+2] anionic annulation has been newly developed, the cascade process of which has a high preference for regiochemical control and chemoselectivity, giving rise to exclusively Michael-type adducts in moderate to high yields (up to 94 %, 35 examples). By making use of this approach as a key operation, the first total synthesis of natural antibiotic ABX, in racemic form, has been successfully
Ph<sub>3</sub>P-mediated highly selective C(α)–P coupling of quinone monoacetals with R<sub>2</sub>P(O)H: convenient and practical synthesis of <i>ortho</i>-phosphinyl phenols
作者:Ruwei Shen、Ming Zhang、Jing Xiao、Chao Dong、Li-Biao Han
DOI:10.1039/c8gc02918k
日期:——
A highlyselective Ph3P-mediated C(α)–P coupling reaction of quinone monoacetals with secondary phosphine oxides is developed to provide an effective method for the synthesis of a wide array of ortho-phosphinylphenols in good to excellent yields. This protocol can be adopted for scale-up synthesis directly from cheap and abundant phenols, and the products can be easily obtained in high yields by simple
new twist: A one‐pot nitrous acid free, diazonium‐free, and transition‐metal‐free variation of the Fischer indole synthesis has been developed. Condensation of quinone monoketals and aliphatic hydrazine hydrochlorides afforded indoles via intermediate alkylaryldiazenes. This method will complement the classical Fischer indole synthesis by providing indoles in two steps from widely available phenols
Regiospecific nucleophilic aromatic substitution: conjugate addition of active methylene compounds to quinone monoacetals and aromatization of the adducts