An enantiospecific and versatile synthesis of statine
摘要:
A short, enantiospecific synthesis of statine is described, starting from a readily available aldehyde. The control of chirality was effected by using the Sharpless asymmetric epoxidation procedure.
The organocatalytic enantio- and diastereoselective cycloetherification of 1,3-cyclohexanedione-bearing enones involving the in situ generation of chiral cyanohydrins was developed. This transformation offers the first catalytic asymmetric approach to oxadecalin derivatives containing contiguous tetrasubstituted chiral carbons at the bridge heads of the fused ring systems. Depending on substituents
Hydroxymethylation beyond Carbonylation: Enantioselective Iridium-Catalyzed Reductive Coupling of Formaldehyde with Allylic Acetates via Enantiotopic π-Facial Discrimination
作者:Victoria J. Garza、Michael J. Krische
DOI:10.1021/jacs.6b01078
日期:2016.3.23
2-propanol-mediated reductive coupling of branched allylic acetates 1a-1o with formaldehyde to form primary homoallylic alcohols 2a-2o with excellent control of regio- and enantioselectivity. These processes, which rely on enantiotopic π-facial discrimination of σ-allyliridium intermediates, represent the first examples of enantioselective formaldehyde C-C coupling beyond aldol addition.
SEGPHOS 修饰的手性铱配合物可催化 2-丙醇介导的支链烯丙乙酸酯 1a-1o 与甲醛的还原偶联,形成高烯丙醇 2a-2o,并具有出色的区域选择性和对映选择性控制。这些过程依赖于 σ-烯丙基铱中间体的对映体 π-面辨别,代表了羟醛加成以外的对映选择性甲醛 CC 偶联的第一个例子。
Palladium(II)-Catalyzed Intramolecular Aminocarbonylation of <i>endo</i>-Carbamates under Wacker-Type Conditions
Pd(II)-catalyzed intramolecularaminocarbonylation of olefins bearing many types of nitrogen nucleophiles has been examined under two typical conditions: acidic conditions [conditions A, typically PdCl(2) (0.1 equiv) and CuCl(2) (3.0 equiv) under 1 atm of CO at room temperature in methanol] and buffered conditions [conditions B, typically PdCl(2) (0.1 equiv) and CuCl(2) (2.3 equiv) under 1 atm of CO at
InI-mediated direct allylation of carbonyl compounds with allylic alcohols proceeded smoothly with catalytic amounts of Ni(acac)2 and PPh3 to give the corresponding homoallylic alcohols in high yields. Allylindium compounds were shown to be the real allylating agents in the present system. Substituted allylic alcohols gave branched homoallylic alcohols with syn-selectivity irrespective of the geometry
Grubbs Cross-Metathesis Pathway for a Scalable Synthesis of γ-Keto-α,β-unsaturated Esters
作者:Reji N. Nair、Thomas D. Bannister
DOI:10.1021/jo4023606
日期:2014.2.7
A direct and scalable route to γ-keto-α,β-unsaturated esters, useful intermediates in medicinal chemistry and natural products synthesis, is reported. The key step involves the use of Grubbs’ second-generation olefin metathesis catalyst for cross-metathesis of alkyl acrylates and 2° allylic alcohols. The metathesis step is followed by oxidation to give the desired products in high yield on scales of
报道了一种直接且可扩展的 γ-酮基-α,β-不饱和酯途径,它是药物化学和天然产物合成中有用的中间体。关键步骤涉及使用 Grubbs 的第二代烯烃复分解催化剂进行丙烯酸烷基酯和 2° 烯丙醇的交叉复分解。复分解步骤之后是氧化,以高达 25 g 的规模以高产率提供所需的产品。