Synthesis, structure and antiproliferative activity of chiral polyamines based on a 2-azanorbornane skeleton
摘要:
A series of enantiopure 2-azanorbornane-based amines were prepared via a stereoselective aza-Diels-Alder reaction and further modifications of the obtained cycloadduct. In particular, derivatives containing two bicyclic moieties linked by N-C-C-N fragments were synthesized. Two dimeric derivatives exhibited a significant antiproliferative activity against selected cell lines, comparable to cisplatin in certain cases. (C) 2016 Elsevier Ltd. All rights reserved.
Reduction of carbonyl compounds with trialkoxysilane can be readily catalyzed by alkoxides of alkali metal. A considerable high asymmetric induction takes place by use of optically active diolates or even N-lithio 2-amino alcoholates derived from optically active amino acid as a catalyst.
cis-Dihydroxylation of electron deficient olefins catalysed by an oxo-bridged diiron(III) complex with H2O2
作者:Ambica Kejriwal、Sachidulal Biswas、Achintesh N. Biswas、Pinaki Bandyopadhyay
DOI:10.1016/j.molcata.2015.11.023
日期:2016.3
acetic acid. The catalytic system has been shown to oxidise electron-deficient olefins to the corresponding cis-diols, while epoxidation is favoured in case of electron-rich olefins. The μ-oxo diiron(III) core of the catalyst 1 has been found be regenerated after the catalytic turnovers. Addition of a second batch of substrate and oxidant at the end of the olefin oxidation results in the formation of
室由一个对称的(μ-氧代)(μ-羟基)二铁催化的烯烃的温度氧化(III)配合物(1)的基础上氨基吡啶基配体bpmen(bpmen = Ñ,Ñ '二甲基Ñ,Ñ N'-双描述了在限制底物的条件下用过氧化氢的(2-吡啶基甲基)乙烷-1,2-二胺。在环境反应条件下,已实现了出色的底物转化率。已经发现1 / H 2 O 2体系的烯烃氧化效力在乙酸的存在下得到改善。已表明催化体系可将缺电子的烯烃氧化为相应的顺式-二醇,而在富含电子的烯烃的情况下,环氧化是有利的。已经发现催化剂1的μ-氧代二铁(III)核在催化周转之后被再生。在烯烃氧化结束时添加第二批底物和氧化剂导致形成几乎相同量的环氧化物/二醇。此外,再生的催化剂对缺电子烯烃的氧化表现出明显更高的优先性。
Manganese catalyzed cis-dihydroxylation of electron deficient alkenes with H2O2
作者:Pattama Saisaha、Dirk Pijper、Ruben P. van Summeren、Rob Hoen、Christian Smit、Johannes W. de Boer、Ronald Hage、Paul L. Alsters、Ben L. Feringa、Wesley R. Browne
DOI:10.1039/c0ob00102c
日期:——
A practical method for the multigram scale selective cis-dihydroxylation of electron deficient alkenes such as diethyl fumarate and N-alkyl and N-aryl-maleimides using H2O2 is described. High turnovers (>1000) can be achieved with this efficient manganese based catalyst system, prepared in situ from a manganese salt, pyridine-2-carboxylic acid, a ketone and a base, under ambient conditions. Under optimized conditions, for diethyl fumarate at least 1000 turnovers could be achieved with only 1.5 equiv. of H2O2 with d/l-diethyl tartrate (cis-diol product) as the sole product. For electron rich alkenes, such as cis-cyclooctene, this catalyst provides for efficient epoxidation.
Gold(I)-Catalyzed Domino Cyclizations of Diynes for the Synthesis of Functionalized Cyclohexenone Derivatives. Total Synthesis of (−)-Gabosine H and (−)-6-<i>epi</i>-Gabosine H
作者:Bojan Vulovic、Dusan Kolarski、Filip Bihelovic、Radomir Matovic、Maja Gruden、Radomir N. Saicic
DOI:10.1021/acs.orglett.6b01898
日期:2016.8.5
position undergo gold(I)-catalyzed domino-cyclization which affords α-hydroxycyclohexenones. The described sequence can be applied on functionalized, highly oxygenated substrates, as examplified in the synthesis of (−)-gabosine H and its epimer.
Benzylidene acetals of 1,2- and 1,3-glycols are easily cleft by diisobutylaluminumhydride in a toluene solution at 0 °C–room temperature to give the corresponding monobenzyl ethers of the glycols. In general the reaction proceeds excellently in regioselective manner depending on the stereochemical environment.
1,2- 和 1,3- 乙二醇的亚苄基缩醛很容易被二异丁基氢化铝在甲苯溶液中在 0 °C - 室温下裂解,得到相应的乙二醇单苄基醚。通常,该反应根据立体化学环境以区域选择性方式出色地进行。