52221-91-7Relevant articles and documents
Modular and Facile Access to Chiral α-Aryl Phosphates via Dual Nickel- and Photoredox-Catalyzed Reductive Cross-Coupling
Li, Yuqiang,Wang, Hepan,Wu, Xiaoqiang,Xu, Tao,Zheng, Purui
supporting information, p. 3989 - 3997 (2022/03/08)
Chiral phosphine-containing skeletons are important motifs in bioactive natural products, pharmaceuticals, chiral catalysts, and ligands. Herein, we report a general and modular platform to access chiral α-aryl phosphorus compounds via a Ni/photoredox-catalyzed enantioconvergent reductive cross-coupling between α-bromophosphates and aryl iodides. This dual catalytic regime exhibited high efficiency and good functional group compacity. A wide variety of substrates bearing a diverse set of functional groups could be converted into chiral phosphates in good to excellent yields and enantioselectivities. The utility of the method was also demonstrated by the development of a new phosphine ligand and the synthesis of enzyme inhibitor derivatives. The detailed mechanistic studies supported a radical chain process and revealed a unique distinction compared with traditional reductive cross-coupling.
Copper-Catalyzed Conjugate Addition of Carbonyls as Carbanion Equivalent via Hydrazones
Luo, Siyi,Peng, Marie,Querard, Pierre,Li, Chen-Chen,Li, Chao-Jun
, p. 13111 - 13117 (2021/09/18)
Copper-catalyzed conjugate addition is a classic method for forming new carbon-carbon bonds. However, copper has never showed catalytic activity for umpolung carbanions in hydrazone chemistry. Herein, we report a facile conjugate addition of hydrazone catalyzed by readily available copper complexes at room temperature. The employment of mesitylcopper(I) and electron-rich phosphine bidentate ligand is a key factor affecting reactivity. The reaction allows various aromatic hydrazones to react with diverse conjugated compounds to produce 1,4-adducts in yields of about 20 to 99%.
Nickel-Catalyzed Enantioconvergent Reductive Hydroalkylation of Olefins with α-Heteroatom Phosphorus or Sulfur Alkyl Electrophiles
Fu, Yao,He, Shi-Jiang,Li, Yan,Lu, Xi,Wang, Jia-Wang,Wang, Xiao-Xu,Xu, Zhe-Yuan
, (2020/01/22)
Substantial advances in enantioconvergent C(sp3)-C(sp3) bond formation reactions have been made in recent years through the use of transition-metal-catalyzed cross-coupling reactions of racemic secondary alkyl electrophiles with organometallic reagents. Herein, we report a general process for the asymmetric construction of alkyl-alkyl bonds adjacent to heteroatoms, namely, a nickel-catalyzed enantioconvergent reductive hydroalkylation of olefins with α-heteroatom phosphorus or sulfur alkyl electrophiles. Including the use of readily available olefins, this reaction has considerable advantages, such as mild reaction conditions, a broad substrate scope, and good functional group compatibility, making it a desirable alternative to traditional electrophile-nucleophile cross-coupling reactions.
Carbonyls as Latent Alkyl Carbanions for Conjugate Additions
Dai, Xi-Jie,Wang, Haining,Li, Chao-Jun
supporting information, p. 6302 - 6306 (2017/05/19)
Conjugate addition of carbon nucleophiles to electron-deficient olefins is one of the most powerful methods for forming carbon–carbon bonds. Despite great achievements in controlling the selectivity, variation of the carbon nucleophiles remains largely underexplored, with this approach relying mostly on organometallic reagents. Herein, we report that naturally abundant carbonyls can act as latent carbon nucleophiles for conjugate additions through a ruthenium-catalyzed process, with water and nitrogen as innocuous byproducts. The key to our success is homogeneous ruthenium(II) catalysis, combined with phosphines as spectator ligands and hydrazine as the reducing agent. This chemistry allows the incorporation of highly functionalized alkyl fragments into a vast array of electron-deficient olefins under mild reaction conditions in a reaction complementary to the classical organometallic-reagent-based conjugate additions mediated or catalyzed by “soft” transition metals.
Copper-catalyzed synthesis of alkylphosphonates from H-phosphonates and N-tosylhydrazones
Miao, Wenjun,Gao, Yuzhen,Li, Xueqin,Gao, Yuxing,Tang, Guo,Zhao, Yufen
, p. 2659 - 2664 (2013/01/15)
A new catalytic system for the alkylation of H-phosphonates and diphenylphosphine oxide with N-tosylhydrazones has been developed. In the presence of copper(I) iodide and base, H-phosphonates react with N-tosylhydrazones to afford the corresponding coupled alkylphosphonates in good to excellent yields without any ligands. Alkylphosphonates can also be prepared in a one-pot process directly from carbonyl compounds without the isolation of tosylhydrazone intermediates.
Direct conversion of benzylic and allylic alcohols to phosphonates
Barney, Rocky J.,Richardson, Rebekah M.,Wiemer, David F.
scheme or table, p. 2875 - 2879 (2011/05/19)
Benzyl phosphonate esters often serve as reagents in Horner-Wadsworth- Emmons reactions. In most cases, they can be prepared from benzylic alcohols via formation of the corresponding halide followed by an Arbuzov reaction. To identify a more direct synthesis of phosphonate esters, we have developed a one-flask procedure for conversion of benzylic and allylic alcohols to the corresponding phosphonates through treatment with triethyl phosphite and ZnI2.
Room-temperature alternative to the arbuzov reaction: The reductive deoxygenation of Acyl phosphonates
Kedrowski, Sean M. A.,Dougherty, Dennis A.
supporting information; experimental part, p. 3990 - 3993 (2010/11/02)
The reductive deoxygenation of acyl phosphonates using a Wolff-Kishner-like sequence is described. This transformation allows direct access to alkyl phosphonates from acyl phosphonates at room temperature. The method can be combined with acyl phosphonate synthesis into a one pot, four-step procedure for the conversion of carboxylic acids into alkyl phosphonates. The methodology works well for a variety of aliphatic acids and shows a functional group tolerance similar to that of other hydrazone-forming reactions.
Rh-catalyzed Negishi alkyl-aryl cross-coupling leading to α- or β-phosphoryl-substituted alkylarenes
Takahashi, Hideki,Inagaki, Shinya,Yoshii, Naoko,Gao, Fuxing,Nishihara, Yasushi,Takagi, Kentaro
supporting information; body text, p. 2794 - 2797 (2009/09/08)
The catalytic cross-coupling between ArZnX and ICH2(CH 2)nP(O)(OEt)2 (n = 0-3) has been investigated to determine the utility of the Rh catalyst during the alkyl-aryl cross-coupling and to develop a new syntheti
Microwave-assisted cleavage of phosphate, phosphonate and phosphoramide esters
Kishore Kumar,Saenz, David,Lokesh,Natarajan, Amarnath
, p. 6281 - 6284 (2007/10/03)
A mild and rapid protocol for cleavage of phosphate, phosphonate and phosphoramide esters. The scope and limitations of this microwave-assisted reaction is explored here.
Hydrophosphorylation of alkenes with dialkyl phosphites catalyzed by Mn(III) under air
Tayama, Osamu,Nakano, Atsushi,Iwahama, Takahiro,Sakaguchi, Satoshi,Ishii, Yasutaka
, p. 5494 - 5496 (2007/10/03)
A facile method for the synthesis of organophosphonates from alkenes and dialkyl phosphites was developed by the use of Mn(II) under air. Thus, the reaction of 1-octene with diethyl phosphite in the presence of Mn(OAc) 2 (5 mol %) under air at 90 °C led to diethyl octylphosphonate (78%) and diethyl (2-hexyl)decylphosphonate (6%). Internal alkenes such as cis-2-octene gave a regioisomeric mixture of the corresponding hydrophosphorylation products in 84% yields.
