18593-19-6Relevant academic research and scientific papers
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
supporting information, 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
supporting information, 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.
O -Phthalaldehyde catalyzed hydrolysis of organophosphinic amides and other P(O)-NH containing compounds
Li, Bin-Jie,Simard, Ryan D.,Beauchemin, André M.
, p. 8667 - 8670 (2017/08/10)
Over 50 years ago, Jencks and Gilchrist showed that formaldehyde catalyses the hydrolysis of phosphoramidate through electrophilic activation, induced by covalent attachment to its nitrogen atom. Given our interest in the use of aldehydes as catalysts, this work was revisited to identify a superior catalyst, o-phthalaldehyde, which facilitates hydrolyses of various organophosphorus compounds bearing P(O)-NH subunits under mild conditions. Interestingly, chemoselective hydrolysis of the P(O)-N bonds could be accomplished in the presence of P(O)-OR bonds.
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
supporting information, 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.
Ruthenium-catalyzed C-H activation/cyclization for the synthesis of phosphaisocoumarins
Park, Youngchul,Jeon, Incheol,Shin, Seohyun,Min, Jiae,Lee, Phil Ho
, p. 10209 - 10220 (2013/11/06)
An efficient and cost-effective ruthenium-catalyzed oxidative cyclization of phosphonic acid monoesters or phosphinic acids with alkynes has been developed for the synthesis of a wide range of phosphaisocoumarins in good to excellent yields under aerobic conditions. A multitude of arylphosphonic acid monoesters and arylphosphinic acids having electron-donating and -withdrawing groups were oxidatively cyclized. Various diarylacetylenes, dialkylacetylenes, and alkylarylacetylenes effectively underwent the ruthenium-catalyzed oxidative cyclization. A substrate possessing benzoic acid as well as a phenylphosphonic monoester moiety was smoothly cyclized with hex-3-yne to afford a compound having both isocoumarin and phosphaisocoumarin moieties. Alkenylphosphonic monoester afforded phosphorus 2-pyrone through oxidative cyclization with alkyne. Competition experiments between diaryl- and dialkylalkynes and between diarylacetylenes having p-methoxy and p-chloro groups gave results which showed that the present oxidative cyclizations were not affected by the electronic effects of alkynes. Mechanistic studies revealed C-H bond metalation to be the rate-limiting step.
Rhodium-catalyzed oxidative C-H activation/cyclization for the synthesis of phosphaisocoumarins and phosphorous 2-pyrones
Park, Youngchul,Seo, Jungmin,Park, Sangjune,Yoo, Eun Jeong,Lee, Phil Ho
supporting information, p. 16461 - 16468 (2013/12/04)
Rhodium-catalyzed cyclization of phosphinic acids and phosphonic monoesters with alkynes has been developed. The oxidative annulation proceeds with complete conversion of phosphinic acid derivatives and allowed the atom-economic preparation of useful phosphaisocoumarins with high yield and selectivity. The reaction is tolerant of extensive substitution on the phosphinic acid, phosphonic monoester and alkyne, including halides, ketone, and hydroxyl groups as substituents. Furthermore, we found that alkenylphosphonic monoesters proceed to give a wide range of phosphorus 2-pyrones through oxidative annulation with alkynes. Mechanistic studies revealed that Ci￡H bond metalation was the rate-limiting step. Copyright
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.
ALKYLATION REACTIONS OF DIALKYL HYDROGEN PHOSPHITES AND DIARYLPHOSPHINE OXIDES UNDER PHASE-TRANSFER CONDITIONS
Petrov, K. A.,Sivova, L. I.,Smirnov, I. V.,Kryukova, L. Yu.
, p. 264 - 268 (2007/10/02)
It was shown that phosphonates and tertiary phosphine oxides can be synthesized by the alkylation of acid phosphites and diarylphosphine oxides in a nonpolar solvent in presence of solid potassium hydroxide and potassium carbonate and also catalytic amounts of 18-crown ether (or in its absence). (Diarylphosphinyl)methyl ethers of mono- and oligo-etylene glycols were synthesized by the reactions of diaryl(chloromethyl)phosphine oxides with lithium glycolates
