Cyclopropanation of alkenes with metallocarbenes generated from monocarbonyl iodonium ylides
作者:Tristan Chidley、Graham K. Murphy
DOI:10.1039/c8ob02636j
日期:——
Reacting Wittigreagents and the hypervalent iodine reagent iodosotoluene, in the presence of 10 mol% Cu(tfacac)2 and 5 equiv. of alkene, results in a novel cyclopropanation reaction. The reagent combination is believed to generate a transient monocarbonyliodoniumylide (MCIY) in situ, which can be intercepted by the copper catalyst to give a metallocarbene. Both ester and ketone derived phosphoranes
Selective carbene transfer to amines and olefins catalyzed by ruthenium phthalocyanine complexes with donor substituents
作者:Lucie P. Cailler、Andrey P. Kroitor、Alexander G. Martynov、Yulia G. Gorbunova、Alexander B. Sorokin
DOI:10.1039/d0dt04090h
日期:——
Electron-rich ruthenium phthalocyanine complexes were evaluated in carbene transfer reactions from ethyl diazoacetate (EDA) to aromatic and aliphatic olefins as well as to a wide range of aromatic, heterocyclic and aliphatic amines for the first time. It was revealed that the ruthenium octabutoxyphthalocyanine carbonyl complex [(BuO)8Pc]Ru(CO) is the most efficient catalyst converting electron-rich
富电子钌酞菁配合物是首次从重氮乙酸乙酯(EDA)到芳香族和脂肪族烯烃以及各种芳香族,杂环和脂肪族胺的卡宾转移反应中进行评估的。结果表明,八丁氧基酞菁钌羰基络合物[(BuO)8Pc] Ru(CO)是最有效的催化剂,在低催化剂负载和几乎等摩尔的底物条件下,可以将高电子含量和电子贫乏的芳族烯烃转化为环丙烷衍生物,并具有高收率(通常为80–100%)和高TON(最高为1000)。 / EDA比。该催化剂在卡宾插入胺N–H键中显示出罕见的效率。使用0.05摩尔%的催化剂负载量,高胺浓度(1M)和1.1当量。在EDA的作用下,许多结构不同的胺被选择性地转化为单取代的甘氨酸衍生物,其定量收率和周转数均达到2000。高选择性,大底物范围,低催化剂载量和实际反应条件[[BuO)8 Pc ] Ru(CO)是卡宾插入胺中最有效的催化剂。
Transition metal-catalyzed cyclopropanation of alkenes in fluorinated alcohols
The system hexafluoroisopropanol/ethyl diazoacetate/Cu(OTf)2 is efficient for the cyclopropanation reaction. The process is experimentally simple, and efficient with various olefins in particular terminal, disubstituted double bonds.
Modular Access to Substituted Azocanes via a Rhodium-Catalyzed Cycloaddition–Fragmentation Strategy
作者:Megan H. Shaw、Rosemary A. Croft、William G. Whittingham、John F. Bower
DOI:10.1021/jacs.5b05215
日期:2015.7.1
A short entry to substituted azocanes by a Rh-catalyzed cycloaddition–fragmentation process is described. Specifically, exposure of diverse N-cyclopropylacrylamides to phosphine-ligated cationic Rh(I) catalyst systems under a CO atmosphere enables the directed generation of rhodacyclopentanone intermediates. Subsequent insertion of the alkene component is followed by fragmentation to give the heterocyclic
描述了通过 Rh 催化的环加成-断裂过程对取代的偶氮烷的简短介绍。具体来说,在 CO 气氛下将不同的 N-环丙基丙烯酰胺暴露于膦配位的阳离子 Rh(I) 催化剂体系可以直接生成罗达环戊酮中间体。随后插入烯烃组分,然后断裂,得到杂环目标。立体化学研究首次表明,烯烃插入到罗达环戊酮中是可逆的。
Mechanochemical Simmons–Smith cyclopropanation<i>via</i>ball-milling-enabled activation of zinc(0)
作者:Lorenzo Pontini、Jamie A. Leitch、Duncan L. Browne
DOI:10.1039/d3gc00649b
日期:——
The bulk solvent-free synthesis of cyclopropanesviaa ball-milling-enabled Simmons–Smith reaction is herein described.