Enantio- and diastereoselective cyclopropanation with tert-butyl α-diazopropionate catalyzed by dirhodium(II) tetrakis[N-tetrabromophthaloyl-(S)-tert-leucinate]
The first successful example of a catalytic asymmetriccyclopropanation with α-diazopropionates is described. The cyclopropanation reaction of 1-aryl-substituted and related conjugated alkenes with tert-butyl α-diazopropionate has been achieved by catalysis with dirhodium(II) tetrakis[N-tetrabromophthaloyl-(S)-tert-leucinate], Rh2(S-TBPTTL)4, providing the corresponding cyclopropane products containing
Asymmetric Synthesis of Isoindolones by Chiral Cyclopentadienyl-Rhodium(III)-Catalyzed CH Functionalizations
作者:Baihua Ye、Nicolai Cramer
DOI:10.1002/anie.201404895
日期:2014.7.21
Directed Cp*RhIII‐catalyzed carbon–hydrogen (CH) bond functionalizations have evolved as a powerful strategy for the construction of heterocycles. Despite their high value, the development of related asymmetric reactions is largely lagging behind due to a limited availability of robust and tunable chiral cyclopentadienyl ligands. Rhodium complexes comprising a chiral Cp ligand with an atropchiral
Enantioselective C–H Annulation of Indoles with Diazo Compounds through a Chiral Rh(III) Catalyst
作者:Xiaohong Chen、Shujing Yang、Helong Li、Bo Wang、Guoyong Song
DOI:10.1021/acscatal.7b00104
日期:2017.4.7
The asymmetric C–H annulation of O-pivaloyl 1-indolehydroxamic acid with donor/acceptor diazocompounds has been achieved for the first time, to the best of our knowledge, by using a rhodium catalyst embedded in a chiral binaphthyl backbone. This protocol constitutes a straightforward route for the synthesis of a new family of 1,2-dihydro-3H-imidazo[1,5-a]indol-3-one derivatives having a quaternary
据我们所知,通过使用嵌入在手性联萘骨架中的铑催化剂,首次实现了O-新戊酰基1-吲哚羟肟酸与供体/受体重氮化合物的不对称CH环化。该协议为合成具有季碳立构中心的1,2-二氢-3 H-咪唑并[1,5- a ]吲哚-3-one衍生物的新家族提供了一条简单的路线,该路线具有高收率和出色的对映选择性(至98:2 er)。
CATALYTIC ASYMMETRIC INTERMOLECULAR C–H INSERTION OF 1,4-CYCLOHEXADIENE WITH α-ALKYL-α-DIAZOESTERS USING CHIRAL DIRHODIUM(II) CARBOXYLATES
The first example of dirhodium(II) complex-catalyzed asymmetric intermolecular C-H insertion with alpha-alkyl-alpha-diazoesters is described. The reaction of 1,4-cyclohexadiene with 2,4-dimethyl-3-pentyl alpha-alkyl-alpha-diazoacetates under catalysis by dirhodium(II) tetrakis[N-phthaloyl-(S)-tert-leucinate], Rh-2(S-PTTL)(4), or dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], Rh-2(S-TFPTTL)(4), gave the corresponding C-H insertion products with enantioselectivities of up to 86% ee, albeit in low to modest yields.