Organophosphites: An Addition to the Arsenal of Organocatalysts

Organophosphites are nucleophilic in nature and can act as a good leaving group owing to the stability of the phosphite anion. This dual reactivity makes them good candidates for nucleophilic organocatalysis. However, phosphites were introduced only in 2004 as the umpolung catalyst for acylsilane substrates utilizing sequential Brook rearrangements. Very recently, phosphites have been reported to catalyze aza-rearrangements and radical reactions. In this review, we discuss the reactivity parameters to understand its lack of use, as well as the potential for catalysis.     

γ辐照三烷基氧化膦的红外光谱研究

混合三烷基氧化膦（ＴＲＰＯ）是一种优良的镧系元素和镧元素萃取剂,已用于放废液的α核素的萃取分离。本文用傅里叶红外光谱法研究γ辐照的３０％ＴＰＯ－煤油－ＨＮＯ３体系的辐照稳定性,结果显示,该萃取剂对放射性辐射是稳定的,主要的辐解产物是硝基烷和羟酸。     

Flux synthesis of (3,4)-connected zinc phosphites with different framework topologies

Two three-dimensional open-framework zinc phosphites, H₂aem·Zn₃(HPO₃)₄·0.5H₂O (1) and H₂apm·Zn₃(HPO₃)₄ (2), have been synthesized by a phosphorous acid flux method, where aem=4-(2-aminoethyl)morpholine and apm=4-(3-aminopropyl)morpholine. Compound 1 crystallizes in the monoclinic system, P2₁/c, a=9.5852(7) Å, b=20.3941(8) Å, c=10.5339(8) Å, β=94.125(9)°, V=2053.8(2) Å³, Z=4, R₁=0.0319, wR₂=0.0628. Compound 2 crystallizes in the monoclinic system, P2₁/n, a=8.589(2) Å, b=14.020(3) Å, c=16.606(3) Å, β=97.190(8)°, V=1983.9(7) Å³, Z=4, R₁=0.0692, wR₂=0.1479. Both compounds are based on (3,4)-connected networks with 8- and 12-ring channels, which are constructed from Zn₃(HPO₃)₄ clusters as the same secondary building units. These inorganic clusters are spatially organized by different structure-directing agents into different three-dimensional frameworks.     

生物素标记试剂的合成方法改进及其在DNA合成中的应用

以生物素,4,4’-二甲氧基三苯基氯甲烷,6-氨基-1-己醇,2-氰基乙氧基-双(N,N-二异丙基)亚磷酰胺等为原料,采用改进方法合成了生物素标记试剂——[1-N-(4,4’-二甲氧基三苯甲基)-生物素-6-氨基己基]-2-氰乙氧基-N,N-二异丙基亚磷酰胺(3),总收率51.0%,其结构经1H NMR,13C NMR,31P NMR和MS确证。通过固相亚磷酰胺三酯法,应用3合成了一段含有十个碱基的5’-端生物素标记的寡核苷酸链,其结构经MS确证。     

A concise method for synthesis of diaryl aryl- or alkylphosphonates

A convenient method has been developed to synthesize diaryl arylphosphonates from triaryl phosphites, triethyl phosphite, and aromatic halides. The new method relies on the triethyl phosphite assisted nickel catalyzed Arbuzov reaction and can be applied to synthesize certain diaryl alkylphosphonates without catalysts.     

A novel layered bimetallic phosphite intercalating with organic amines: Synthesis and characterization of Co(H2O)4Zn4(HPO3)6·C2N2H10

A new layered cobalt-zinc phosphite, Co(H₂O)₄Zn₄(HPO₃)₆·C₂N₂H₁₀ has been synthesized in the presence of ethylenediamine as the structure-directing agent. The compound crystallizes in the monoclinic system, space group Cc (No. 9), a=18.2090(8), b=9.9264(7), c=15.4080(7) Å, β=114.098(4)°, V=2542.3(2) Å³, Z=4, R=0.0323, wR=0.0846. The structure consists of ZnO₄ tetrahedra, CoO₆ octahedra and HPO₃ pseudopyramids through their vertices forming bimetallic phosphite layers parallel to the ab plane. Organic cations, which reside between the inorganic layers, are mobile and can be exchanged by NH₄⁺ cations without the collapse of the framework.     

Ga3(HPO3)4F4(H3DETA) (DETA=diethylenetriamine): A new open-framework fluorinated gallium phosphite with pentameric building unit

Ga₃(HPO₃)₄F₄(H₃DETA) is a new open-framework fluorinated gallium phosphite obtained by mild hydrothermal synthesis using diethylenetriamine as templated agent and characterized by single crystal X-ray diffraction, the powder X-ray diffraction, IR spectroscopy, TGA, ICP and elemental analyses. It crystallizes in the monoclinic space group C2/c, a=12.741(6) Å, b=12.068(6) Å, c=11.988(5) Å, β=94.902(8)^o, V=1836.6(15) Å³, Z=4. The construction of 3D open-framework structure in the title compound may be viewed as the assembly of pentameric building units and HPO₃ groups. The pentameric building unit is the first to be found, which lead to form the three types of channels along a-, b- and c-axes, respectively, in gallium phosphite. The triprotonated DETA cations are inserted within the 10-membered ring channels and interact with anions of the framework via hydrogen bonds.     

Diastereoselective addition of dimethyl phosphite to 3,3′,4,4′-tetramethyl-1,1′-diphosphaferrocene-2-carboxaldehyde

Addition of dimethyl phosphite to racemic 3,3′,4,4′-tetramethyl-1,1′-diphosphaferrocene-2-carboxaldehyde gives almost exclusively one diastereomer of the corresponding α-hydroxyphosphonate (d.r. ?96:4). Its absolute configuration (S, R_p)-(R, S_p) was established by X-ray diffraction.     

(C5H6N)4[Be6(HPO3)8]·H2O: A low-density open-framework beryllium phosphite with multidirectional 12-ring channels

Employing the common pyridine (=py) solvent as the source of structure-directing agents (SDAs), a novel three-dimensional open-framework beryllium phosphite (Hpy)₄[Be₆(HPO₃)₈]·H₂O (1), has been solvothermally synthesized and structurally characterized by IR, elemental analysis, thermogravimetric analysis, powder and single-crystal X-ray diffractions. It crystallizes in the orthorhombic system, space group Pbca (No. 61), a = 20.0034(4) Å, b = 20.2188(4) Å, c = 20.9731(3) Å, V = 8482.5(3) Å³, and Z = 8. The alternating connection of BeO₄ tetrahedra and HPO₃ pseudopyramids give rise to a (3, 4)-connected network with multidirectional intersecting 12-ring channels. The compound possesses a low density and a new {4.8.10}{4².6.8.10.12}{4².6}₃{4².8.10².12}{4³.6².8} topology.     

Hydroformylation of methyl-3-pentenoate over a phosphite ligand modified Rh/SiO2 catalyst

A phosphite ligand modified Rh/SiO2 catalyst has been developed for hydroformylation of internal olefins to linear aldehydes, which showed high activity and regioselectivity and could be separated easily by filtration after reaction in an autoclave. Effects of reaction temperature and syngas pressure on the performances of the catalyst in the reaction were also investigated.