Double cyclization of allyloxybenzoic acid chlorides mediated by samarium diiodide giving cyclopropanols
作者:Mitsuru Sasaki、Jacqueline Collin、Henri B. Kagan
DOI:10.1016/s0040-4039(00)82276-5
日期:——
Cyclopropanols were easily obtained by an unusual double cyclization of 2-allyloxybenzoic acid chlorides mediated by samariumdiiodide in THF. A tentative mechanism is discussed.
Zinc-Mediated Hydroxyallylation of Aldehydes with Cyclopropanols: Direct Access to Vicinal <i>anti</i>-<i>sec</i>,<i>tert</i>-Diols via Enolized Homoenolates
作者:Yoshiya Sekiguchi、Naohiko Yoshikai
DOI:10.1021/acs.orglett.1c04331
日期:2022.1.28
by zinc-mediated α-hydroxyallylation of aldehydes with cyclopropanols. The reaction features the action of the zinc-enolized homoenolate as a γ-oxyallyl nucleophile toward the carbonyl electrophile. The diastereoselectivity of the present reaction is ascribed to the strong preference for a chelated (Z)-configuration of the enolized homoenolate as well as the bicyclic chairlike transition state it forms
Zinc-Catalyzed β-Functionalization of Cyclopropanols via Enolized Homoenolate
作者:Yoshiya Sekiguchi、Naohiko Yoshikai
DOI:10.1021/jacs.1c10109
日期:2021.11.10
involves zinc homoenolate and its enolization to generate a key bis-nucleophilic species. α-Allylation of this “enolized homoenolate” with MBH carbonate would be followed by regeneration of the cyclopropane ring and irreversible lactonization. The enolized homoenolate mechanism has also been proven to allow for β-functionalization with alkylidenemalononitrile as the reaction partner. A sequence of the present
SASAKI, MITSURU;COLLIN, JACQUELINE;KAGAN, HENRI B., TETRAHEDRON LETT., 29,(1988) N 47, C. 6105-6106
作者:SASAKI, MITSURU、COLLIN, JACQUELINE、KAGAN, HENRI B.
DOI:——
日期:——
Cyclization and Ring-Expansion Processes Involving Samarium Diiodide Promoted Reductive Formation and Subsequent Oxidative Ring Opening of Cyclopropanol Derivatives
convert to cyclic conjugated enones in moderate to good yields. In addition, the reduction−oxidation reaction sequences can be successfully performed in one pot. The regioselectivities of cyclopropane ringopening in the bicyclic substrates depend on the oxidizing agents used. For example, reactions promoted by FeCl3 with pyridine lead to the expected ring-expansion process involving internal-bond cleavage
io二碘化物促进了各种α-溴甲基环烷酮的反应,然后用三甲基甲硅烷基氯进行处理,导致嵌在双环[ m .1.0]烷烃骨架中的环丙基甲硅烷基醚的生产。用氧化性电子转移试剂(例如Fe(III),Ce(IV)和Mn(III)盐)处理醚时,会生成扩环酮,并以中等至良好的产率转化为环状共轭烯酮。另外,还原氧化反应序列可以在一锅中成功进行。双环底物中环丙烷开环的区域选择性取决于所用的氧化剂。例如,FeCl 3促进的反应用吡啶导致预期的扩环过程,该过程涉及双环烷烃的内部键裂解并产生环烯酮作为最终产物。相反,与Ce(NH 4)2(NO 3)6或Mn(OAc)3作为氧化剂的反应通过外键裂解进行,得到α-碘甲基环烷酮。