一系列六个开链四吡咯已被合成并用作植物光感受器蛋白光敏色素的发色团。新的发色团在环 D 的取代基 17 和 18 的大小不同。该环在光激发时会发生最大的构象变化(Z --> E 15,16-双键的光异构化)。已生成二甲基、甲基和异丙基、甲基和叔丁基、乙基和甲基、乙烯基和甲基以及异丙基和甲基取代基,而不是天然生色团植物色素中存在的甲基和乙烯基取代基(17、18 位)。所有新型生色团都与脱辅基蛋白组装。与天然色素相比,所获得的色蛋白的吸光度最大值最大为 10 nm,除了 17-异丙基-18-甲基取代的化合物显示出 100 nm 的选择性 P r 形式的红移。组装动力学随着取代基尺寸的增加而减慢,对 17 位改性取代基的影响更强。 18-异丙基和 18-叔丁基取代基的光诱导 P fr 形式的热稳定性甚至更高比原生颜料要好。那些在第 17 位带有比甲基(乙基和异丙基)大的取代基的发色团显示出各自 P
Diastereoselectivity in the triethylamine-catalyzed sulfa-Michael addition of thiols to nitroalkenes: kinetic and thermodynamic control
作者:Jiandong Wang、Ning Chen、Jiaxi Xu
DOI:10.1016/j.tet.2015.04.053
日期:2015.6
sulfa-Michael addition of nitroalkenes and thiols was investigated. The sulfa-Michael addition is kineticcontrol at the beginning and thermodynamiccontrol at the end for less bulky reactants. Thus, kinetic and thermodynamic-controlled adducts can be obtained as major products by controlling the reaction time in those cases. Linear nitroalkenes generally produce anti-adducts as major kinetic products due
Construction of Multisubstituted Tetrahydropyrans by a Domino Oxa-Michael/Tsuji–Trost Reaction
作者:Liang Wang、Dirk Menche
DOI:10.1021/jo302102x
日期:2012.12.7
Biologically significant tetrahydropyrans (THP) were synthesized by a Tandemoxa-Michael/Tsuji–Trostreaction. Different Michael acceptors were investigated, and optimal results in terms of diastereoselectivities and yields were obtained with nitro olefins. The influence of the reaction parameters, substrate patterns, and type of metal counterions on the yield and stereochemical outcome of this process
An efficient [3+2] cycloaddition for the synthesis of substituted pyrazolo[1,5-c]quinazolines
作者:Tao Wang、Ailong Shao、Haiyan Feng、Shuwu Yang、Meng Gao、Jun Tian、Aiwen Lei
DOI:10.1016/j.tet.2015.03.019
日期:2015.7
and efficient [3+2] cycloaddition reaction between N-iminoquinazolinium ylide and nitroolefins was developed. From a synthetic point of view, this protocol represents an efficient way to pyrazolo[1,5-c]quinazolines derivatives.
开发了N-亚氨基喹唑啉鎓叶立德和硝基烯烃之间简单有效的[3 + 2]环加成反应。从综合的观点来看,该方案代表了吡唑并[1,5- c ]喹唑啉衍生物的有效方法。
A new synthesis of allylic alcohols or their derivatives via reductive elimination from γ-phenylthio-β-nitroalcohols with tributyltinhydride
作者:Noboru Ono、Akio Kamimura、Aritsune Kaji
DOI:10.1016/s0040-4039(01)81593-8
日期:——
Allylic alcohols are readily prepared by the Bu3SnH-promoted elimination reaction from γ-phenylthio-β-nitroalcohls which are obtained by the joint reaction of nitroolefins, thiophenol, and aldehydes.
for the diversifiedsynthesis of furans and arenofurans has been developed that proceeds through K2CO3‐promoted cyclization between enols/1,3‐dicarbonyl compounds and nitroolefins at reflux in EtOH. This facile method has been successfully employed in the synthesis of benzotrifuran derivatives, which are useful hole‐transporting materials. This procedure also provides directaccess to dioxa[5]helicenes
已经开发了一种多样化合成呋喃和槟榔呋喃的通用方法,该方法通过在EtOH中回流,通过K 2 CO 3促进烯醇/ 1,3-二羰基化合物与硝基烯烃之间的环化反应来进行。这种简便的方法已成功用于苯并三呋喃衍生物的合成,苯并三呋喃衍生物是有用的空穴传输材料。该程序还提供了直接接触二氧杂[5]螺旋的方法。该反应提供了广泛的底物范围,使用了廉价的碱和对环境无害的溶剂,并且操作简单。