66147-02-2Relevant academic research and scientific papers
A Titanium-Catalyzed Reductive α-Desulfonylation
Kern, Christoph,Selau, Jan,Streuff, Jan
supporting information, p. 6178 - 6182 (2021/03/16)
A titanium(III)-catalyzed desulfonylation gives access to functionalized alkyl nitrile building blocks from α-sulfonyl nitriles, circumventing traditional base-mediated α-alkylation conditions and strong single electron donors. The reaction tolerates numerous functional groups including free alcohols, esters, amides, and it can be applied also to the α-desulfonylation of ketones. In addition, a one-pot desulfonylative alkylation is demonstrated. Preliminary mechanistic studies indicate a catalyst-dependent mechanism involving a homolytic C?S cleavage.
Nucleophilic Reactivities of Bis-Acceptor-Substituted Benzyl Anions
Puente, ángel,Ofial, Armin R.,Mayr, Herbert
supporting information, p. 1196 - 1202 (2017/03/11)
The kinetics of the reactions of bis-acceptor-substituted benzyl anions (PhCXY–, X,Y = CN, CO2Et, COPh, SO2Ph) with benzhydrylium ions and quinone methides (reference electrophiles) have been determined in dimethyl sulfoxide solution at 20 °C. The reactions follow second-order kinetics, first order with respect to the electrophile and first order with respect to the carbanion. The addition of 18-crown-6 ether, which efficiently coordinates to the anions' counter ions K+, did not affect the kinetics, which indicates that the measured rate constants refer to the reactivities of the nonpaired carbanions. Comparison with the reactivities of the structurally analogous secondary carbanions HCXY– shows that replacement of H at the carbanionic center by Ph reduces the nucleophilic reactivities towards a reference benzhydrylium ion by factors in the range of only 1.2 (X,Y = SO2Ph) to 6 (X,Y = CO2Et). The plots of lg k2 versus the electrophilicity parameters E of the reference electrophiles are linear, thereby indicating that the correlation lg k2(20 °C) = sN(E + N), which characterizes nucleophiles by the two solvent-dependent parameters sN and N and electrophiles by the parameter E, is applicable. In this way, it becomes possible to integrate these carbanions into our comprehensive nucleophilicity scale, which provides a direct comparison of the nucleophilic reactivities of different families of compounds.
Synergistic effect of a bis(proazaphosphatrane) in mild palladium-catalyzed direct α-arylations of nitriles with aryl chlorides
Han Kim, So,Jang, Wonseok,Kim, Min,Verkade, John G.,Kim, Youngjo
, p. 6025 - 6029 (2015/03/30)
The effect of a bis(proazaphosphatrane) ligand on the palladium-catalyzed direct α-arylation of nitriles with various aryl chlorides under mild conditions is reported. Comparisons of the catalytic properties of this ligand with those of three related mono(proazaphosphatrane)s under the same reaction conditions revealed that bis(proazaphosphatrane) displayed a synergistically enhanced activity. In the presence of the bis(proazaphosphatrane) ligand, ethyl cyanoacetate and primary as well as secondary nitriles were efficiently coupled with a wide variety of aryl chlorides that contained electron-rich, electron-poor, and electron-neutral groups.
Palladium-catalyzed Negishi α-arylation of alkylsulfones
Zhou, Gang,Ting, Pauline C.,Aslanian, Robert G.
experimental part, p. 939 - 941 (2010/05/18)
A general, mild catalytic system for α-monoarylation of various alkyl sulfones is described that utilizes palladium-catalyzed Negishi cross-coupling approach.
A General Method for the Direct α-Arylation of Nitriles with Aryl Chlorides
You, Jingsong,Verkade, John G.
, p. 5051 - 5053 (2007/10/03)
The long-standing challenge of developing a general method for the title methodology is met for a broad range of aryl chlorides through the use of bicyclic P(iBuNCH2CH2)3N (1) as a bulky electron-rich ligand for palladium (see scheme, dba = dibenzylideneacetone).
P(i-BuNCH2CH2)3N: An efficient ligand for the direct α-arylation of nitriles with aryl bromides
You, Jingsong,Verkade, John G.
, p. 8003 - 8007 (2007/10/03)
A new catalyst system for the synthesis of α-aryl-substituted nitriles is reported. The bicyclic triaminophosphine P(i-BuNCH 2CH2)3N (1b) serves as an efficient and versatile ligand for the palladium-catalyzed direct α-arylation of nitriles with aryl bromides. Using ligand 1b, ethyl cyanoacetate and primary as well as secondary nitriles are efficiently coupled with a wide variety of aryl bromides possessing electron-rich, electron-poor, electron-neutral, and sterically hindered groups.
Palladium-catalyzed arylation of sulfonyl CH-acids
Kashin, Alexander N,Mitin, Anton V,Beletskaya, Irina P,Wife, Richard
, p. 2539 - 2542 (2007/10/03)
A method for the palladium-catalyzed monoarylation of a series of functionalized sulfones by aryl halides is described. The reaction proceeds in the presence of 2 mol% of Pd2dba3·CHCl3 (dba=dibenzylideneacetone), PPh3 and NaH as a base, only with relatively strong CH-acids and gives monoarylated products in moderate to high yields.
A Convenient Synthesis of Some Arylated Phenylsulfonylacetonitriles and Ethyl Cyanoacetates Using Organo-iron Complexes
Abd-El-Aziz, Alaa S.,Denus, Christine R. de
, p. 293 - 298 (2007/10/02)
A general method for the synthesis of some arylated phenylsulfonylacetonitriles 6a-g, 10a, b and 16 and ethyl cyanoacetates 7a-d and 11a, b is described.Nucleophilic substitution of the cyclopentadienyliron complexes of chloroarenes 1a-g with phenylsulphonylacetonitrile 2 or ethyl cyanoacetate 3 in the presence of potassium carbonate in DMF, at room temperature under a nitrogen atmosphere gave cyclopentadienyliron complexes of arylated phenylsulphonylacetonitriles 4a-g, 8a, b and 15 and ethyl cyanoacetates 5a-d and 9a, b in very good yields (71-94percent).Photolysis of these complexes liberated the arenes (70-91percent).To demonstrate the versatility of this methodological approach, reactions of both carbon nucleophiles 2, 3 with dimethyl chlorobenzene complexes 1h, j gave the desired products 8a, 9a, 12 and 13 without significant steric effect.This synthesis is advantageous over all those previously reported and should be a practical route to a variety of alkanoic acid and heterocyclic precursors.
New Triazine Derivatives as Potent Modulators of Multidrug Resistance
Dhainaut, Alain,Regnier, Gilbert,Atassi, Ghanem,Pierre, Alain,Leonce, Stephane,et al.
, p. 2481 - 2496 (2007/10/02)
A series of 70 triazine derivatives have been synthesized and tested for their capacity to modulate multidrug resistance (MDR) in DC-3F/AD and KB-A1 tumor cells in vitro, in comparison with verapamil (VRP), a calcium channel antagonist currently used in therapy as an antihypertensive drug, which also shows MDR modulating activity.Among the 12 selected compounds, 16 (S9788) showed high MDR reversing properties in vitro (300- and 6-fold VRP at 5μM in DC-3F/AD and KB-A1 cells, respectively) and induced a strong accumulation of adriamycin.The relationship between the increase of ADR accumulation and the fold reversal induced by these compounds and their lack of effects on the sensitive DC-3F cells suggest that they act mainly by inhibiting the P-glycoprotein (Pgp) catalyzed efflux of cytotoxic agents, as already described for a majority of MDR modulators.In vivo, in association with the antitumor drug vincristine (0.25 mg/kg), 16 (100 mg/kg) increased the T/C by 39percent in mice bearing the resistant tumor cell line P388/VCR.According to these interesting properties, 16 was selected for a clinical development because it is more bioavailable than 34, even though it was less active.
