Asymmetric Inter- and Intramolecular Cyclopropanation Reactions Catalyzed by a Reusable Macroporous-Polymer-Supported Chiral Ruthenium(II)/Phenyloxazoline Complex
Along came poly: A novel macroporous polymer‐supported chiral RuII/pheox catalyst (1, see SEM image) afforded excellent reactivity and enantioselectivity in inter‐ and intramolecular cyclopropanation reactions with a broad range of substrates. The catalyst showed no leaching and could be reused up to 11 times, even after storage.
随之而来的是聚:一种新型的大孔聚合物负载的手性Ru II / pheox催化剂(1,参见SEM图片)在与多种底物的分子间和分子内环丙烷化反应中具有出色的反应性和对映选择性。该催化剂没有浸出,即使在储存后也可以重复使用多达11次。
Enantioselective Intramolecular Cyclopropanations of Allylic and Homoallylic Diazoacetates and Diazoacetamides Using Chiral Dirhodium(II) Carboxamide Catalysts
作者:Michael P. Doyle、Richard E. Austin、A. Scott Bailey、Michael P. Dwyer、Alexey B. Dyatkin、Alexey V. Kalinin、Michelle M. Y. Kwan、Spiros Liras、Christopher J. Oalmann
DOI:10.1021/ja00126a016
日期:1995.5
counterparts, but allylicdiazoacetates are subject to greater variations in enantioselectivities with changes in substitution patterns on the carbon-carbon double bond. For example, the enantioselectivities in the intramolecularcyclopropanations of 3-allcyl/aryl-2(Z)-alken-l-y1 diazoacetates are generally 194%, whereas the cyclizations of the homologous 4-alkyl/aryl-3(Z)-alken1-yl diazoacetates are typically
Remarkably Stable Iron Porphyrins Bearing Nonheteroatom-Stabilized Carbene or (Alkoxycarbonyl)carbenes: Isolation, X-ray Crystal Structures, and Carbon Atom Transfer Reactions with Hydrocarbons
作者:Yan Li、Jie-Sheng Huang、Zhong-Yuan Zhou、Chi-Ming Che、Xiao-Zeng You
DOI:10.1021/ja020391c
日期:2002.11.1
spectrometry, and elemental analyses. X-raycrystalstructure determinations of 1.0.5C(6)H(6).0.5CH(2)Cl(2) and 4 reveal Fe=CPh(2) bond lengths of 1.767(3) (1) and 1.827(5) A (4), together with large ruffling distortions of the TPFPP macrocycle. Complexes 2 and 4 are reactive toward styrene, affording the corresponding cyclopropanes in 82 and 53% yields, respectively. Complex 1 is an active catalyst for both
Bidentate carbenoid ester coordination in ruthenium(ii) Schiff-base complexes leading to excellent levels of diastereo- and enantioselectivity in catalytic alkene cyclopropanation
作者:Ian J. Munslow、Kevin M. Gillespie、Robert J. Deeth、Peter Scott
DOI:10.1039/b104964j
日期:——
Exceptionally high stereoselectivity (ee ⩽ 98%, dr ⩽
99∶1) in the cyclopropanation of alkenes with ethyl diazoacetate
using a non-planar ruthenium(II) Schiff-base precatalyst is a
result of η2C,O binding of the carbenoid ester
intermediate, according to DFT calculations.
Enantioselective Intramolecular Iridium-Catalyzed Cyclopropanation of α-Carbonyl Sulfoxonium Ylides
作者:Lucas Vidal、Pan-Pan Chen、Eva Nicolas、Andrew Hackett、Craig M. Robertson、Kendall N. Houk、Christophe Aïssa
DOI:10.1021/acs.orglett.2c03396
日期:2022.11.25
Enantioselective cyclopropanation of α-carbonyl sulfoxonium ylides (SY) has so far been limited to addition/ring closure reactions on electron-poor olefins. Herein, we report the iridium-catalyzed intramolecular cyclopropanation of SY in the presence of a chiral diene in up to 96% yield and 98% enantioselectivity. Moreover, density functional theory calculations suggest that the re face of the olefin
迄今为止,α-羰基亚砜 (SY) 的对映选择性环丙烷化仅限于缺电子烯烃的加成/闭环反应。在此,我们报道了在手性二烯存在下铱催化的 SY 分子内环丙烷化反应,收率高达 96%,对映选择性高达 98%。此外,密度泛函理论计算表明,烯烃的表面优选在与烯烃的几何结构无关的异步协同步骤中攻击铱卡宾中间体。