献给斯科特教授丹麦在他65之际个生日。 发布时间为致力于斯科特E.丹麦在他65之际特殊部分的部分次生日。 抽象的 用锌试剂对酸酐进行催化脱对称可提供脱氧聚丙酸酯和聚丙酸酯合成子的途径。进行离子霉素的合成,其中使用这种方法将四个片段中的三个组装在一起。两种策略(烯醇硅烷/氧碳鎓偶联和还原环化)均未成功安装C23立体中心,但通过还原/ S N 2方法克服了该立体化学问题。除了合成离子霉素的受保护的非对映异构体之外,C17–C32片段的合成还构成正式的总合成。 用锌试剂对酸酐进行催化脱对称可提供脱氧聚丙酸酯和聚丙酸酯合成子的途径。进行离子霉素的合成,其中使用这种方法将四个片段中的三个组装在一起。两种策略(烯醇硅烷/氧碳鎓偶联和还原环化)均未成功安装C23立体中心,但通过还原/ S N 2方法克服了该立体化学问题。除了合成离子霉素的受保护的非对映异构体之外,C17–C32片段的合成还构成正式的总合成。
Tied back: The title reaction was observed when a silicon‐tethered diene was treated with the Hoveyda–Grubbs second‐generation catalyst. The structural requirements for the E‐olefin‐formingring‐closing metathesis, and the transition state leading to E olefin are discussed. This methodology will be useful in the synthesis of polyketides containing a pent‐2‐ene‐1,5‐diol unit.
Desymmetrizing Hydroformylation with the Aid of a Planar Chiral Catalyst-Directing Group
作者:Bernhard Breit、Daniel Breuninger
DOI:10.1021/ja0467364
日期:2004.8.1
Desymmetrizinghydroformylation of bisalkenyl- and bisallylcarbinols could be achieved employing a chiral substrate-bound catalyst-directinggroup (o-DPPF) with excellent levels of diastereotopic alkene face and diastereotopic alkene group discrimination to give bifunctionalized chiral aldehydes in enantiomerically pure form.
Enantioselective synthesis of 2,6-dideoxy carbasugars based on a desymmetrizing hydroformylation–carbonyl ene cyclization process
作者:Bernhard Breit、Aurélien Bigot
DOI:10.1039/b817786d
日期:——
A practical one-pot process involving a desymmetrizinghydroformylation with the aid of a chiral catalyst-directinggroup (CDG*), followed by a carbonyl ene cyclization provides a straightforward access to both enantiomers of the resulting cyclohexanediol; further divergent, highly selective and protecting group-free transformations furnish the carbocyclic analogues of four important 2,6-dideoxysugars
The structures of the O‐glycosyltransferaseLanGT2 and the engineered, CC bond‐forming variant LanGT2S8Ac show how the replacement of a single loop can change the functionality of the enzyme. Crystal structures of the enzymes in complex with a nonhydrolyzable nucleotide‐sugar analogue revealed that there is a conformational transition to create the binding sites for the aglycon substrate. This induced‐fit
Stereoselective Rh-Catalyzed Hydrogenative Desymmetrization of Achiral Substituted 1,4-Dienes
作者:Héctor Fernández-Pérez、Joan R. Lao、Anton Vidal-Ferran
DOI:10.1021/acs.orglett.6b01088
日期:2016.6.17
Highly efficient catalytic stereoselective hydrogenative desymmetrization reactions mediated by rhodiumcomplexes derived from enantiopure phosphine–phosphite (P–OP) ligands are described. The highest performing ligand, which contains a TADDOL-derived phosphite fragment [TADDOL = (2,2-dimethyl-1,3-dioxolane-4,5-diyl)bis(diphenylmethanol)], presented excellent catalytic properties for the desymmetrization