Enantioselective Synthesis of
<i>cis</i>
‐Decalin Derivatives by the Inverse‐Electron‐Demand Diels–Alder Reaction of 2‐Pyrones
作者:Xu‐Ge Si、Zhi‐Mao Zhang、Cheng‐Gong Zheng、Zhan‐Ting Li、Quan Cai
DOI:10.1002/anie.202006841
日期:2020.10.12
A novel strategy for the synthesis of cis‐decalins by an ytterbium‐catalyzed asymmetric inverse‐electron‐demand Diels–Alderreaction of 2‐pyrones and silyl cyclohexadienol ethers is reported here. A broad range of synthetically important cis‐decalin derivatives with multiple contiguous stereogenic centers and functionalities are obtained in good yields and stereoselectivities. A full set of diastereomeric
obtained enantiomerically pure by employing the chiral copper-phosphoramidite complex [Cu(OTf)2 L*] as a highly efficient catalyst for their kineticresolution (>99 % ee at 52 % conversion, selectivity S>200). These important building blocks can be obtained on a synthetically interesting scale, as was demonstrated by the successful multigram resolution of 5-methyl-2-cyclohexenone. Tf=trifluoromethanesulfonyl
通过使用手性铜-亚磷酰胺络合物[Cu(OTf)2 L *]作为其动力学拆分的高效催化剂,可以得到对映体纯的多种取代的2-环己酮,如(R)-1 (> 99% ee,转化率为52%,选择性S> 200)。这些重要的结构单元可以以合成有趣的规模获得,如成功的5-甲基-2-环己烯酮的克数解析度所证明的那样。Tf =三氟甲磺酰基。
Kinetic resolution of 5-substituted cycloalkenones by peptidic amidophosphane-copper-catalyzed asymmetric conjugate addition of dialkylzinc
Asymmetricconjugate alkylation reaction of racemic 5-substituted cyclohexenones with dialkylzinc reagents was catalyzed by 2–5 mol % of dipeptidic amidophosphane-Cu(MeCN)4BF4 in toluene at 0 °C for 20 min to recover enantioenriched starting 5-substituted cyclohexenones with 88–98% ee in 28–41% yield along with trans major 3-alkylated 5-substituted cyclohexanones with 81–90% ee in 53–60% yield. Complete
Enantiodivergent Preparation of Optically Pure Tricyclic Cyclohexanoids via Lipase-Mediated Asymmetrization of a meso-Symmetric Starting Material
作者:Minoru Moriya、Takashi Kamikubo、Kunio Ogasawara
DOI:10.1055/s-1995-3879
日期:1995.2
Two potentially useful, optically pure, tricyclohexanoids having 1,4-ethanohydronaphthalen-5-one system have been prepared in an enantiodivergent way from a single chiral tricyclic cyclohexanoid precursor obtained by lipase-mediated asymmetrization of a meso-symmetric starting material.
Synergistic Cu–amine catalysis for the enantioselective synthesis of chiral cyclohexenones
作者:A. Quintard、J. Rodriguez
DOI:10.1039/c5cc02987b
日期:——
An unprecedented utilization of 1,3-acetonedicarboxylic acid as a 1,3-bis-pro-nucleophile and a reactive acetone surrogate in enantioselective catalysis has been reported.