Distal γ‐C(sp
<sup>3</sup>
)−H Olefination of Ketone Derivatives and Free Carboxylic Acids
作者:Han Seul Park、Zhoulong Fan、Ru‐Yi Zhu、Jin‐Quan Yu
DOI:10.1002/anie.202003271
日期:2020.7.27
Reported herein is the distal γ‐C(sp3)−H olefination of ketone derivatives and free carboxylic acids. Fine tuning of a previously reported imino‐acid directing group and using the ligand combination of a mono‐N‐protected amino acid (MPAA) and an electron‐deficient2‐pyridone were critical for the γ‐C(sp3)−H olefination of ketone substrates. In addition, MPAAs enabled the γ‐C(sp3)−H olefination of free carboxylic
An improved synthesis of 1-azoniatricyclo[4.4.3.01,6]tridecane (2) and the preparation of the remaining member of the series, 1-azoniatricyclo[4.3.3.01,6]dodecane salts (3) have been achieved. Using a combination of 1H (at 400 MHz) and 13C NMR spectra has allowed the assignment of the signals in the well-resolved 1H spectra. The results indicate that 1 exists in the all-chair form which undergoes racemization
已经实现了1-氮杂三环[4.4.3.0 1,6 ]十三烷(2)的改进的合成以及该系列的剩余成员1-氮杂三环[4.3.3.0 1,6 ]十二烷盐(3)的制备。通过结合使用1 H(在400 MHz下)和13 C NMR光谱,可以在良好分辨的1 H光谱中分配信号。结果表明1以全椅子形式存在,其以0.7秒-的速率常数通过环反转经历消旋化,并且进一步地,这些盐中的抗衡离子被限制为仅与四面体N原子的一个表面缔合。
Iron-catalysed allylation–hydrogenation sequences as masked alkyl–alkyl cross-couplings
作者:Josef Bernauer、Guojiao Wu、Axel Jacobi von Wangelin
DOI:10.1039/c9ra07604b
日期:——
organomagnesium reagents (alkyl, aryl) with simple allyl acetates proceeds under mild conditions (Fe(OAc)2 or Fe(acac)2, Et2O, r.t.) to furnish various alkene and styrene derivatives. Mechanistic studies indicate the operation of a homotopic catalyst. The sequential combination of such iron-catalysed allylation with an iron-catalysed hydrogenation results in overall C(sp3)–C(sp3)-bond formation that constitutes
在温和条件下(Fe(OAc) 2或 Fe(acac) 2 , Et 2 O, rt),有机镁试剂(烷基、芳基)与简单的乙酸烯丙酯发生铁催化烯丙基化反应,得到各种烯烃和苯乙烯衍生物。机理研究表明了同伦催化剂的运作。这种铁催化烯丙基化与铁催化氢化的顺序组合导致整体C(sp 3 )–C(sp 3 )-键形成,这构成了具有挑战性的与烷基卤化物的直接交叉偶联方案的有吸引力的替代方案。
Regio‐ and Diastereoselective Copper‐Catalyzed Carbomagnesiation for the Synthesis of Penta‐ and Hexa‐Substituted Cyclopropanes
作者:Yair Cohen、André U. Augustin、Laura Levy、Peter G. Jones、Daniel B. Werz、Ilan Marek
DOI:10.1002/anie.202102509
日期:2021.5.17
Despite the highly strained nature of cyclopropanes possessing three vicinal quaternary carbon stereocenters, the regio‐ and diastereoselective copper‐catalyzed carbomagnesiation reaction of cyclopropenes provides an easy and efficient access to these novel persubstituted cyclopropyl cores with a complete regio‐ and diastereoselectivity.
4-hydroxy-2-cyclopentenone, process for production thereof,
申请人:Teijin Limited
公开号:US04711895A1
公开(公告)日:1987-12-08
A 4-hydroxy-2-cyclopentenone represented by the following formula (I) ##STR1## wherein X represents a hydrogen or halogen atom, A represents a hydrogen atom and B represents a hydroxyl group, or A and B are bonded to each other to represent a bond, R.sup.1 represents a substituted or unsubstituted alkyl, alkenyl or alkynyl group having 1 to 10 carbon atoms, R.sup.2 represents a substituted or unsubstituted alkyl, alkenyl or alkynyl group having 1 to 10 carbon atoms, and R.sup.3 represents a hydrogen atom or a protective group for a hydroxyl group, provided that R.sup.2 is not a 2-octenyl, 8-acetoxy-2-octenyl or 2,5-octadienyl group. The compounds of formula (I) in which A is hydrogen and B is hydroxyl group are prepared by subjecting a 5-unsubstituted cyclopentenone and an aldehyde to aldol condensation reaction. The compounds of formula (I) in which A and B form a bond is prepared by subjecting the compounds of the formula (I) in which A is hydrogen and B is hydroxyl group to dehydration. The compounds (I) are useful for treatment of malignant tumors.