The development of a novel asymmetric ringopening of bi- and polycyclic hydrazines with aryl organometallic reagents is presented. The application of this reaction to the most simple bicyclic hydrazine 1a gives a straightforward regio- and diastereoselective access to synthetically useful trans 3,4-disubstituted hydrazinocyclopentenes in an enantioenriched form.
trimethylaluminum in "noncoordinating" solvents, leading to the corresponding aminophosphine which is the real ligand in copper-catalyzed asymmetric transformations. This artifact explains the experimental differences in the asymmetric ringopening of meso bicyclic hydrazines using dialkylzinc or trialkylaluminum reagents as nucleophiles.
An Enantioselective Cp
<sup>x</sup>
Rh(III)‐Catalyzed C−H Functionalization/Ring‐Opening Route to Chiral Cyclopentenylamines
作者:Shou‐Guo Wang、Nicolai Cramer
DOI:10.1002/anie.201813953
日期:2019.2.18
oxidant was developed for a C−H activation/ring‐opening sequence between aryl ketoxime ethers and 2,3‐diazabicyclo[2.2.1]hept‐5‐enes. This transformation provides access to densely functionalized chiral cyclopentenylamines in excellent yields and enantioselectivities of up to 97:3 er. The reported method is also well suitable for asymmetric alkenyl C−Hfunctionalizations of α,β‐unsaturated oxime ethers
开发了由Cp x Rh I(鳕鱼)预催化剂和双(邻甲苯甲酰基)过氧化物作为活化氧化剂生成的手性Cp x Rh III催化剂体系,用于芳基酮肟醚和2,3-二氮杂双环[2.2.1]庚-5-烯。这种转化提供了以优异的收率和高达97:3 er的对映选择性进入致密官能化手性环戊烯胺的途径。所报道的方法也非常适用于α,β-不饱和肟醚的不对称烯基CH官能化,为跳过的二烯提供了高水平的对映控制。
SimplePhos Monodentate Ligands: Synthesis and Application in Copper-Catalyzed Reactions
作者:Laëtitia Palais、Igor S. Mikhel、Chloée Bournaud、Laurent Micouin、Caroline A. Falciola、Magali Vuagnoux-d'Augustin、Stéphane Rosset、Gérald Bernardinelli、Alexandre Alexakis
DOI:10.1002/anie.200702186
日期:2007.10.1
LEUENBERGER, C.;HOESCH, L.;DREIDING, A. S., HELV. CHIM. ACTA, 1981, 64, N 4, 1219-1233