Highly Enantioselective Iron-Catalyzed <i>cis</i>
-Dihydroxylation of Alkenes with Hydrogen Peroxide Oxidant via an Fe<sup>III</sup>
-OOH Reactive Intermediate
作者:Chao Zang、Yungen Liu、Zhen-Jiang Xu、Chun-Wai Tse、Xiangguo Guan、Jinhu Wei、Jie-Sheng Huang、Chi-Ming Che
DOI:10.1002/anie.201603410
日期:2016.8.22
catalysts for highly enantioselective asymmetric cis‐dihydroxylation (AD) of alkenes with broad substrate scope remains a challenge. By employing [FeII(L)(OTf)2] (L=N,N′‐dimethyl‐N,N′‐bis(2‐methyl‐8‐quinolyl)‐cyclohexane‐1,2‐diamine) as a catalyst, cis‐diols in up to 99.8 % ee with 85 % isolated yield have been achieved in AD of alkenes with H2O2 as an oxidant and alkenes in a limiting amount. This “[FeII(L)(OTf)2]+H2O2”
开发具有良好底物范围的烯烃的高对映选择性不对称顺二羟基化(AD)的环境友好型催化剂仍然是一个挑战。通过使用[Fe II(L)(OTf)2 ](L = N,N'-二甲基-N,N'-双(2-甲基-8-喹啉基)-环己烷-1,2-二胺)作为催化剂,在以H 2 O 2为氧化剂的烯烃和数量有限的烯烃的AD中,已实现了高达99.8%ee的顺式二醇和85%的分离产率。该“ [Fe II(L)(OTf)2 ] + H 2 O 2”方法适用于(E)-烯烃和末端烯烃(24个实例,ee大于80%,最大1 g)。机理研究包括18种O-标记,UV / Vis,EPR,ESI-MS分析和DFT计算,为手性Fe III- OOH活性物种参与两个C-O键的对映选择性形成提供了证据。
Synthesis and Conformational Analysis of α,β-Difluoro-γ-amino Acid Derivatives
作者:Luke Hunter、Katrina A. Jolliffe、Meredith J. T. Jordan、Paul Jensen、Rene B. Macquart
DOI:10.1002/chem.201003320
日期:2011.2.18
access has been achieved to all possible stereoisomers of the α,β‐difluoro‐γ‐amino acid motif. These novel building blocks can readily be coupled to other amino acids, and the resulting peptides display unique conformational behavior depending on the fluorine stereochemistry. The differences in peptide conformation can be rationalized in terms of the various stereoelectronic effects associated with
形状控制:已经合成了所有可能的α,β-二氟-γ-氨基酸基序的立体异构体。这些新颖的结构单元可以很容易地与其他氨基酸偶联,并且取决于氟的立体化学,所得的肽显示出独特的构象行为。可以根据与C can F键相关的各种立体电子效应,合理化肽构象的差异。
Synlett 2006, 11, 1771-1773
作者:
DOI:——
日期:——
Enantioselective Synthesis of (+)-(<i>S</i>,<i>S</i>)-Reboxetine
An efficient enantioselectivesynthesis leading directly to (+)-(S,S)-reboxetine has been described from commercially available trans-cinnammyl bromide using Sharpless asymmetric dihydroxylation as the key step.