33513-50-7Relevant academic research and scientific papers
Methylation of C(sp3)-H/C(sp2)-H bonds with methanol catalyzed by cobalt system
Liu, Zhenghui,Yang, Zhenzhen,Yu, Xiaoxiao,Zhang, Hongye,Yu, Bo,Zhao, Yanfei,Liu, Zhimin
supporting information, p. 5228 - 5231 (2017/11/06)
A highly efficient Co-based catalytic system, composed of a commercially available Co salt, a tetradentate phosphine ligand P-(CH2CH2PPh2)3(PP3), and a base (denoted as [Co]/PP3/base), is developed for the methylation of C(sp3)-H and C(sp2)-H bonds using methanol as a methylating reagent. The Co(BF4)2.6H2O/PP3/K2CO3 catalytic system showed high catalytic activity for the methylation of C-H bonds in aryl alkyl ketones, aryl acetonitriles, and indoles, with wide substrate scope and good functional group tolerance, and methylsubstituted products were obtained in good to excellent yields at 100 °C. This cheap, readily available, and highly efficient Co-based catalytic system may have promising applications in methylation reaction using methanol.
Rhodium-catalyzed ketone methylation using methanol under mild conditions: Formation of α-branched products
Chan, Louis K. M.,Poole, Darren L.,Shen, Di,Healy, Mark P.,Donohoe, Timothy J.
supporting information, p. 761 - 765 (2014/01/23)
The rhodium-catalyzed methylation of ketones has been accomplished using methanol as the methylating agent and the hydrogen-borrowing method. The sequence is notable for the relatively low temperatures that are required and for the ability of the reaction system to form α-branched products with ease. Doubly alkylated ketones can be prepared from methyl ketones and two different alcohols by using a sequential one-pot iridium- and rhodium-catalyzed process. Uniquely effective for making branched alkyl products from ketones (see scheme): The scope of the presented reaction includes aromatic and aliphatic ketones and consecutive one-pot double alkylation reactions to provide a convenient route to branched ketones from simple methyl ketones. A brief study into the mechanism of the reaction has given evidence for an aldol-based reaction pathway.
Copper-catalyzed direct benzylation or allylation of 1,3-azoles with N -tosylhydrazones
Zhao, Xia,Wu, Guojiao,Zhang, Yan,Wang, Jianbo
, p. 3296 - 3299 (2011/04/24)
Cu-Catalyzed cross-coupling of N-tosylhydrazones with 1,3-azoles leads to the direct C-H benzylation or allylation. Cu carbene migratory insertion is proposed to play the key role in this transformation.
Base Catalysed Rearrangements involving Ylide Intermediates. Part 18. Competing , , and Rearrangements of Ammonium Ylides
Chantrapromma, Kan,Ollis, W. David,Sutherland, Ian O.
, p. 1049 - 1062 (2007/10/02)
The rearrangements of acyl stabilised ammonium ylides are, in several cases, accompanied by competing rearrangements and in one case by a rearrangement.For examples involving migrating benzyl or phenylethyl groups the mechanism of these rearrangements has been studied.Thus the competing , , and rearrangements of the ylide (12) are largely intramolecular, but the intermolecularity is as high as 28percent for the and rearrangements and 14percent for the rearrangement in methanol at 55 deg C.The competing and rearrangements of the optically active (29a) give products with predominant retention of the configuration of the migrating phenylethyl group, but the intramolecular stereoselectivity of the rearrangement is significantly greater than that of the rearrangement.These results are consistent with a radical pair pathway for all three modes of rearrangement.Suitably substituted acyl stabilised allylammonium ylides (55) rearrange by competing , and processes.
