نتایج جستجو برای: aryl grignard
تعداد نتایج: 15617 فیلتر نتایج به سال:
The first asymmetric synthesis of α-allyl-α-aryl α-amino acids by means of a three-component coupling of α-iminoesters, Grignard reagents, and cinnamyl acetate is reported. Notably, the enolate from the tandem process provides a much higher level of reactivity and selectivity than the same enolate generated via direct deprotonation, presumably due to differences in the solvation/aggregation sta...
The total synthesis of the human telomerase inhibitor γ-rubromycin in its racemic form was accomplished in 3.8 % overall yield. The key feature of this synthesis is an efficient acid-catalyzed spiroketalization for the construction of the spiroketal core. The required electronically well-balanced spiroketal precursor was obtained by the convergent assembly of a naphthyl-substituted aldehyde, an...
In this work, we describe the one-pot synthesis of α-amino nitrile units by concomitant addition alkyl (or aryl) Grignard reagents and TMS cyanide through alkylative Strecker cyanation from readily available formamides. The reaction is broad in scope conditions are mild, inexpensive, easy to set-up, providing numerous nitriles good yields (34 examples, 41–94 % yield).
A one-pot, three-step protocol for the preparation of Grignard reagents from organobromides in a ball mill and their subsequent reactions with gaseous carbon dioxide (CO2) or sodium methyl carbonate providing aryl alkyl carboxylic acids up to 82 % yield is reported. Noteworthy are short reaction times significantly reduced solvent amounts [2.0 equiv. liquid assisted grinding (LAG) conditions]. ...
The formation of carbon-nitrogen (C-N) bonds via an umpolung substitution reaction has been achieved at -78 °C without the need for catalysts, ligands, or additives. The scope is limited to aryl Grignard reagents with N-chloroamines. The findings in this manuscript serve as a reference point for all C-N bond formation involving N-chloroamines and organometallic reagents. Knowing the yields of u...
The mechanism of the iron-catalyzed cross-coupling of alkyl halides with aryl Grignard reagents is studied by a combination of GC monitoring and DFT calculation. Herein, we investigate two possible reaction pathways, the regular oxidative addition (OA) pathway and the atom transfer (AT) pathway that might occur in the rate-limiting step. The computational studies revealed that the AT pathway re...
Grignard reagents (RMgBr: R = Et, p-tolyl) selectively attacked the β-position of the bridgehead double bond of tosylazafulleroid through interaction of Mg with the S[double bond, length as m-dash]O group. The following [5,6] ring closure and C-N bond scission led to aryl/alkyl aminylfullerenes with 1,2-configuration. Tolyl-substituted aminylfullerene was further converted into 1,4-di(p-tolyl)f...
A novel selective route to 1,1-bis(silyl)-1-alkenes has been developed. Sequential one-pot silylative coupling exo-cyclization of 1,2-bis(dimethylvinylsiloxy)ethane followed by the reaction with Grignard reagents leads to the desired 1,1-bis(silyl)ethenes, which are then efficiently coupled in the presence of silver nitrate and palladium acetate with aryl or alkenyl idodides to give the corresp...
Arynes participate in three-component coupling reactions with N, S, P, and Se functionalities to yield 1,2-heteroatom-difunctionalized arenes. Using 2-iodophenyl arylsulfonates as benzyne precursors, we could effectively add magnesiated S-, Se-, and N-nucleophilic components to the strained triple bond. In the same pot, addition of electrophilic N, S, or P reagents and a copper(I) catalyst trap...
An improved protocol was described for the amination of chloroarenes with diarylamines under NiCl2(PCy3)2 catalysis in the presence of a Grignard reagent as base. This method fully suits bromo-/iodoarene substrates as well, and even is expanded to certain aryl tosylates. A preliminary investigation into the mechanism suggests that this amination reaction might proceed through Ni(I) and Ni(III) ...
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