84271-84-1Relevant academic research and scientific papers
Synthesis of Tertiary Benzylic Nitriles via Nickel-Catalyzed Markovnikov Hydrocyanation of α-Substituted Styrenes
Xing, Yidan,Yu, Rongrong,Fang, Xianjie
, p. 1008 - 1012 (2020/02/04)
The Markovnikov hydrocyanation of α-substituted styrenes enables the synthesis of tertiary benzylic nitriles under nickel catalysis. The Lewis-acid-free transformation features an unprecedented functional groups tolerance, including the-OH and-NH2 groups. A broad range of tertiary benzylic nitriles were obtained in good to excellent yields. In addition, an asymmetric version of this reaction was preliminarily investigated.
Carbon-carbon bond-forming reductive elimination from arylpalladium complexes containing functionalized alkyl groups. Influence of ligand steric and electronic properties on structure, stability, and reactivity
Culkin, Darcy A.,Hartwig, John F.
, p. 3398 - 3416 (2008/10/09)
A series of arylpalladium alkyl complexes of the formula [(DPPBz)Pd(Ar)(R)] (DPPBz = 1,2-bis(diphenylphosphino)benzene; R = methyl, benzyl, enolate, cyanoalkyl, trifluoroalkyl, or malonate) has been prepared to reveal the influence of steric and electronic parameters on structure, stability, and reactivity. Arylpalladium enolate and cyanoalkyl complexes ligated by EtPh 22P, 1,1-bis(diisopropylphosphino)ferrocene (D iPrPF), and BINAP were prepared to evaluate the effect of the ancillary ligand. The coordination modes of the enolate and cyanoalkyl complexes were determined by spectroscopic methods, in combination with X-ray crystallography. In the absence of steric effects, the C-bound isomer was favored electronically if the enolate or cyanoalkyl group was located trans to a phosphine, and the O-bound isomer was favored if the enolate was located trans to an aryl group. The thermodynamic stability of the enolate and cyanoalkyl complexes was controlled by the steric properties of the enolate or cyanoalkyl group, and complexes with more substitution at the α-carbon were less stable. Arylpalladium methyl, benzyl, enolate, cyanoalkyl, and trifluoroethyl complexes underwent carbon-carbon bond-forming reductive elimination upon heating. Reductive elimination was faster from complexes with electron-withdrawing substituents on the palladium-bound aryl group and with sterically hindered alkyl groups. The electronic properties of the alkyl group had the largest impact on the rate of reductive elimination: electron-withdrawing groups on the α-carbon retarded the rate of reductive elimination. The rates of reductive elimination correlated with the Taft polar substituent constants of the groups on the carbon alpha to the metal.
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.
Synthesis, characterization, and reactivity of arylpalladium cyanoalkyl complexes: Selection of catalysts for the α-arylation of nitriles
Culkin, Darcy A.,Hartwig, John F.
, p. 9330 - 9331 (2007/10/03)
A new coupling process, the palladium-catalyzed α-arylation of nitriles, was developed by exploring the structure and reactivity of arylpalladium cyanoalkyl complexes. Complexes of 1,2-bis(diphenylphosphino)benzene (DPPBz), 1,1′-bis(di-i-propylphosphino)ferrocene (DiPrPF), racemic-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP), and diphenylethylphosphine (PPh2Et) were prepared. Coordination to palladium through the α-carbon was observed for DPPBz-ligated complexes and for complexes of primary and benzylic nitrile anions. However, the anion of isobutyronitrile was coordinated to palladium through the cyano-nitrogen when the complex was ligated by DiPrPF. The isobutyronitrile anion displaced a phosphine ligand to form a C,N-bridged dimer when generated from PPh2Et-ligated palladium. These results suggest that the nitrile anion preferentially coordinates to palladium through the carbon atom in the absence of steric effects. Thermolysis of the arylpalladium cyanoalkyl complexes led to reductive elimination that formed α-aryl nitriles. The high yields and short reaction times observed for BINAP-ligated complexes suggested that BINAP-ligated palladium catalysts might be appropriate for the arylation of nitriles. Initial results on a palladium-catalyzed process for the direct coupling of aryl bromides and primary, benzylic, and secondary nitrile anions to form α-aryl nitriles in good yields are reported. Copyright
Thermodynamic Control of Regioselectivity in the Addition of Carbanions to (Arene)tricarbonylchromium Complexes
Kuendig, E. Peter,Desobry, Vincent,Simmons, Dana P.,Wenger, Eric
, p. 1804 - 1815 (2007/10/02)
The results of a study of question of kinetic or thermodynamic control of the addition of carbon nucleophiles to (arene)Cr(CO)3 complexes are presented. 2-Lithio-2-methylpropionitrile (1) is shown to add reversibly to (naphthalene)Cr(CO)3 (2), (5,8-dimeth
The Stereochemistry of Organometallic Compounds. XXVII. Nucleophilic and Electrophilic Substitution Reactions of Conformationally Restricted Arenechromium Compounds
Jackson, W. Roy,Rae, Ian D.,Wong, Margaret G.
, p. 303 - 315 (2007/10/02)
The regioselectivity of reaction of tricarbonyl(1,1-dimethylindane)chromium with selected electrophiles and nucleophiles has been shown to be influenced by the preferred conformation of the tricarbonylchromium group.Nucleophiles preferentially react at carbon atoms eclipsed by a chromium-carbonyl bond and electrophiles at carbon atoms in staggered positions.When similar reactions were attempted with some chelated arenechromium dicarbonyl phosphorus compounds only low yields of substitution products were obtained.
Perfume compositions as well as perfumed articles and materials containing alkyl substituted benzyl cyanides as a fragrance
-
, (2008/06/13)
Use of one or more alkyl substituted benzyl cyanides having the formula STR1 in which R1 and R2 each may represent a hydrogen atom or a methyl group and R3 represents a branched alkyl group having at most 6 carbon atoms as a perfume component in perfume compositions and in imparting perfume notes to articles for example soaps, cleaning preparations and cosmetic compositions.
