Phenanthroline and tert-butoxide have been established as powerful radical initiators in reactions such as the S(RN)1-type coupling reactions due to the cooperation of large heteroarenes and a special feature of tert-butoxide. The first phenanthroline-tert-butoxide-catalyzed transition-metal-free allylic isomerization is described. The resulting ketones are key intermediates for indenes. The control experiments rule out the base-promoted allylic anion pathway. The radical pathway is supported by experimental evidence that includes kinetic study, kinetic isotope effect, isotope-labeling experiments, trapping experiments, and EPR experiments.
Phosphine-Free NNN-Manganese Complex Catalyzed α-Alkylation of Ketones with Primary Alcohols and Friedländer Quinoline Synthesis
作者:Milan K. Barman、Akash Jana、Biplab Maji
DOI:10.1002/adsc.201800380
日期:2018.9.3
a very simple and inexpensive catalytic system based on Earth's abundant transition metalmanganese and on a bench‐stable phosphine‐free NNN‐pincer ligand for an atom‐efficient α‐alkylations of ketones with primary alcohols via hydrogen‐autotransfer C−C bond formation protocol. The precatalyst could be generated in situ and could be activated by using catalyticamount of base under milder conditions
Suzuki–Miyaura Coupling of Simple Ketones via Activation of Unstrained Carbon–Carbon Bonds
作者:Ying Xia、Jianchun Wang、Guangbin Dong
DOI:10.1021/jacs.8b02462
日期:2018.4.25
Here, we describe that simple ketones can be efficiently employed as electrophiles in Suzuki-Miyauracoupling reactions via catalytic activation of unstrained C-C bonds. A range of common ketones, such as cyclopentanones, acetophenones, acetone and 1-indanones, could be directly coupled with various arylboronates in high site-selectivity, which offers a distinct entry to more functionalized aromatic
在这里,我们描述了通过催化激活无张力的 CC 键,简单的酮可以在 Suzuki-Miyaura 偶联反应中有效地用作亲电子试剂。一系列常见的酮,如环戊酮、苯乙酮、丙酮和1-茚满酮,可以直接与各种芳基硼酸酯以高位点选择性偶联,这为获得更多功能化的芳香酮提供了独特的途径。初步机理研究表明酮 α-CC 键通过氧化加成断裂。
Cobalt(II)porphyrin-Mediated Selective Synthesis of 1,5-Diketones via an Interrupted-Borrowing Hydrogen Strategy Using Methanol as a C1 Source
A novel cobalt(II)porphyrin-mediated acceptorless dehydrogenation of methanol is reported for the first time. This methodology has been applied for the coupling of a variety of ketones with methanol to produce 1,5-diketones along with H2 and H2O as the environment friendly byproducts. This paradigm was also demonstrated for a one-pot synthesis of substitutedpyridines using a sequential addition protocol
RhCl(CO)(PPh 3 ) 2 catalyzed α-alkylation of ketones with alcohols
作者:Rui Wang、Lina Huang、Zhengyin Du、Hua Feng
DOI:10.1016/j.jorganchem.2017.05.055
日期:2017.10
A simple and efficient method for α-alkylation of ketones with primary alcohols catalyzed by RhCl(CO)(PPh3)2 without additional additives under mild conditions is developed. It has a wide substrate scope, high atom-efficiency and chemoselectivity. It is an environmentally friendly method to build CC bond because water is the only byproduct.
palladacycles (1 and 2) were synthesized by the aromatic C–H bond activation of N/3-aryl ring. The application of these regioisomers as catalysts to enable the formation of α-alkylated ketones or quinolines with alcohols using a hydrogen borrowing process is evaluated. Experimental results reveal that palladacycle 2 is superior over palladacycle 1 to catalyze the reaction under similar reaction conditions