59472-84-3Relevant academic research and scientific papers
Light-Enabled Radical 1,4-Aryl Migration Via a Phospho-Smiles Rearrangement
De Abreu, Maxime,Belmont, Philippe,Brachet, Etienne
, p. 3758 - 3767 (2021/02/01)
Rearrangement reactions in organic chemistry are attractive strategies to build efficiently complex scaffolds, in just one step, from simple starting materials. Among them, aryl migrations are certainly one of the most useful and straightforward rearrangement for building attractive carbon-carbon bonds. Of note, anionic aryl migration reactions have been largely described compared to their radical counterparts. Recently, visible-light catalysis has proven its efficiency to generate such radical rearrangements due to the concomitant loss of a particle (often CO2 or SO2), which is the driving-force of the reaction. Here, we disclose a Smiles-type rearrangement, triggered by a phosphorus-containing unit (arylphosphoramidate), therefore called "phospho-Smiles"rearrangement, allowing a Csp2-Csp2 bond formation thanks to a 1,4-aryl migration reaction. In addition, combining this approach with a radical hydroamination/amination reaction produces an amination/phospho-Smiles cascade particularly attractive, for instance, to investigate the synthesis of the phthalazine core, a scarcely described scaffold of interest for medicinal chemistry projects.
Copper mediated C(sp2)-H amination and hydroxylation of phosphinamides
Sun, Shang-Zheng,Shang, Ming,Xu, Hui,Cheng, Tai-Jin,Li, Ming-Hong,Dai, Hui-Xiong
, p. 1444 - 1447 (2020/02/11)
Copper mediated C(sp2)-H amination and hydroxylation of arylphosphinic acid are accomplished by adopting phosphinamide as the directing group. This method is distinguished by its wide substrate scope and excellent functional group tolerance, th
Copper-Catalyzed Oxidative C(sp3)?H/N?H Cross-Coupling of Hydrocarbons with P(O)?NH Compounds: the Accelerating Effect Induced by Carboxylic Acid Coproduct
Lei, Jian,Yang, Yincai,Peng, Lingteng,Wu, Lesong,Peng, Ping,Qiu, Renhua,Chen, Yi,Au, Chak-Tong,Yin, Shuang-Feng
, p. 1689 - 1696 (2019/03/07)
An chelation-assisted oxidative C(sp3)?H/N?H cross coupling of hydrocarbons with P(O)?NH compounds using copper acetate as catalyst is described. The results of kinetic experiments, mechanistic studies and DFT calculations demonstrate the importance of acetic acid coproduct as an additive for promoting the formation of intermediate bis((diphenylphosphoryl)(quinolin-8-yl)amino)copper (6), and consequently accelerating the construction of C(sp3)?N bond. The reaction proceeded efficiently with a wide array of hydrocarbons and P(O)?NH compounds, and the rate acceleration induced by the acetic acid coproduct have been repeatedly proven. Furthermore, the efficiency of small-scale reaction could be retained upon gram-scale synthesis in a continuous manner. (Figure presented.).
Direct, oxidative halogenation of diaryl- or dialkylphosphine oxides with (dihaloiodo)arenes
Eljo, Jasmin,Murphy, Graham K.
supporting information, p. 2965 - 2969 (2018/06/30)
The oxidative halogenation of diaryl- or dialkylphosphine oxides with the hypervalent iodine reagents (difluoroiodo)toluene (p-TolIF2, 1) and (dichloroiodo)benzene (PhICl2, 2) is reported. Phosphoric fluorides could be recovered in 32–75% yield, or they could be trapped with EtOH to give the corresponding phosphinate in typically good yield. Phosphoric chlorides were not readily isolable, and were trapped with alcohol and amine nucleophiles, giving diaryl- or dialkylphos-phinates and phosphinamides in up to 90% yield.
Rhodium(III)-Catalyzed Enantiotopic C?H Activation Enables Access to P-Chiral Cyclic Phosphinamides
Sun, Yang,Cramer, Nicolai
, p. 364 - 367 (2016/12/30)
Compounds with stereogenic phosphorus atoms are frequently used as ligands for transition-metal as well as organocatalysts. A direct catalytic enantioselective method for the synthesis of P-chiral compounds from easily accessible diaryl phosphinamides is presented. The use of rhodium(III) complexes equipped with a suitable atropochiral cyclopentadienyl ligand is shown to enable an enantiodetermining C?H activation step. Upon trapping with alkynes, a broad variety of cyclic phosphinamides with a stereogenic phosphorus(V) atom are formed in high yields and enantioselectivities. Moreover, these can be reduced enantiospecifically to P-chiral phosphorus(III) compounds.
Pd(II)-catalyzed enantioselective synthesis of P-stereogenic phosphinamides via desymmetric C-H arylation
Du, Zhi-Jun,Guan, Jing,Wu, Guo-Jie,Xu, Peng,Gao, Lian-Xun,Han, Fu-She
, p. 632 - 635 (2015/01/30)
We present the enantioselective synthesis of P-stereogenic phosphinamides through Pd-catalyzed desymmetric ortho C-H arylation of diarylphosphinamides with boronic esters. The method represents the first example of the synthesis of P-stereogenic phosphorus compounds via the desymmetric C-H functionalization strategy. The reaction proceeded efficiently with a wide array of reaction partners to afford the P-stereogenic phosphinamides in up to 74% yield and 98% ee. The efficiency was further demonstrated by gram scale syntheses. Moreover, the flexible conversion of the P-stereogenic phosphinamides into various types of P-stereogenic phosphorus derivatives was also elaborated. Thus, the protocol provides a novel tool for the efficient and versatile synthesis of P-stereogenic compounds.
Organophosphorus and Nitro-Substituted Sulfonate Esters of 1-Hydroxy-7-azabenzotriazole as Highly Efficient Fast-Acting Peptide Coupling Reagents
Carpino, Louis A.,Xia, Jusong,Zhang, Chongwu,El-Faham, Ayman
, p. 62 - 71 (2007/10/03)
Organophosphorus esters 9, 10, 14, and 15 prepared via reaction of diethyl- and diphenylphosphoryl chloride, di(o-tolyl)phosphinyl chloride, and 2,8-dimethylphenoxaphosphinyl chloride with HOAt are excellent coupling reagents for peptide synthesis which are generally superior to their uronium/guanidinium analogues and HOBt- or HODhbt-derived phosphate ester counterparts in minimizing loss of configuration during segment coupling. The phosphinyl analogues are more shelf-stable than the phosphoryl systems. The new reagents have been tested in segment couplings leading to two tripeptides (20, 21) and a hexapeptide 22. Outstanding utility is also shown for the solid-phase assembly of the ACP decapeptide. Similar results were obtained with the 2- and 4-nitro- and 2,4-dinitrophenylsulfonyl esters derived from HOAt.
Hydrolysis of Diarylphosphinic Amides in Acidic Solution: Steric Inhibition and Mechanism
Harger, Martin J. P.
, p. 154 - 160 (2007/10/02)
The pseudo-first-order rate constants for the hydrolysis of diphenylphosphinic amide Ph2P(O)NH2 and its di-p-tolyl, di-o-tolyl, and dimesityl analogues (106kψ 3 630, 2 340, 81.0, and 3.27 s-1 respectively with H(1+) 0.0662M and T 30.2 deg C) in water-dioxan (9:1 v/v) containing perchloric acid show that reaction is sterically hindered by ortho-methyl substituents in the P-aryl groups.Steric inhibition is as great, or greater, in the hydrolysis of the corresponding (N-phenyl)diarylphosphinic amides (106kψ 5 440, 4 470, 54.9 and 0.88 s-1 respectively with H(1+) 1.36M and T 39.9 deg C) and (N-p-nitrophenyldiarylphosphinic amides (106kψ 724, 702, 6.57, and 0.098 s-1 respectively with H(1+) 2.58M and T 39.9 deg C) even though the departing amine is less nucleophilic.Such sensitivity to steric hindrance is consistent with associative (A2) mechanism for the hydrolysis of all the substrates.
