Heterocycle-Substituted Phosphinesulfonato Palladium(II) Complexes for Insertion Copolymerization of Methyl Acrylate
摘要:
A family of heterocycle-substituted binuclear phosphinesulfonato Pd(II) complexes {[R2P(C6H4SO2O)]PdMeClLi(dmso)}(2) (1a-d-LiCl-dmso: 1a-LiCl-dmso, R = 2-furyl; 1b-LiCl-dmso, R = 2-thienyl; 1c-LiCl-dmso, R = 2-(N-methyl)pyrrolyl; 1d-LiCl-dmso, R = 2-benzofuryl) was synthesized, and the solid-state structures of 1a-c-LiCl-dmso were determined, which revealed various modes of bridging between the two metal fragments. 1a-d-LiCl-dmso further generated either the mononuclear Pd(II) complexes{[kappa P-2,O-R2P(C6H4SO2O)]PdMe(pyr)} (1a-d-pyr) by addition of pyridine or the more labile mononuclear Pd(II) complex {[kappa P-2,O-(2-thienyl)(2)-P(C6H4SO2O)]PdMe(dmso)} (1b-dmso) by chloride abstraction with AgBF4. Stoichiometric methyl acrylate (MA) insertion experiments indicated that, in comparison with the other three substituents, the thienyl-substituted Pd(II) complexes undergo faster insertion of MA in a primary 2,1-fashion, and lb-dmso possesses the fastest insertion rate due to the relative weakly coordinating dmso molecule. All palladium complexes were employed in ethylene polymerization, affording highly linear polyethylene with relatively low molecular weights (M-n = (0.5-7.4) x 10(3)). In addition, under these pressure reactor conditions, the thienyl motif displays the highest activity (order: 1b-dmso > 1b-pyr > 1a-pyr > 1d-pyr > 1c-pyr >> 1a-d-LiCl-dmso). Copolymerization reactions of ethylene and MA further revealed that MA incorporation in the obtained linear copolymers depends moderately on the heterocyclic substituents.
Visible-Light-Driven Selective Alkenyl C–P Bond Cleavage of Allenylphosphine Oxides
作者:Kai Wei、Kai Luo、Fang Liu、Lei Wu、Li-Zhu Wu
DOI:10.1021/acs.orglett.9b00071
日期:2019.4.5
irradiation, was developed. This novel protocol involves a highly regioselective radical pathway initiated by singlet oxygen, affording diverse alkynyl phosphinates with good-to-excellent yields. Mechanistic studies and density functional theory calculations suggested an intramolecular process involving phosphorus migration, instead of phosphorus radical formation, at the early stage of the reaction
A series of phosphorus-substituted germanium(II) complexes, L1GeR [L1 = CH(CMe)(2,6-iPr2C6H3N)}2; 2, R = PPh2; 4, R = OPPh2; 5a, R = OP(O)Ph2; 5b, R = OP(O) (OnBu)2; 6a, R = OP(S)Ph2; 6b, R = OP(S)(OEt)2], were synthesized through the direct activation of various organic phosphorus compounds by N-heterocyclic ylide-like germylene 1. These compounds were characterized by IR and NMR spectroscopy, and
一系列磷取代的锗(II)配合物,L 1 GeR [L 1 = CH (CMe)(2,6- i Pr 2 C 6 H 3 N)} 2;2,R = PPh 2 ; 4,R = OPPh 2 ; 5a,R = OP(O)Ph 2;5b,R = OP(O)(O n Bu)2;6a,R = OP(S)Ph 2;R = OP(S)Ph 2。6b,R = OP(S)(OEt)2],是通过N-杂环叶立德样的亚二甲基亚砜1直接活化各种有机磷化合物而合成的。通过IR和NMR光谱,以及这些化合物进行了表征4,图5a,图6a和6b中,用X射线晶体学进一步研究。有趣的是,1与Ph 2 P(O)H的反应生成的是三配位磷(III)物种L 1 GeOPPh 2(4),而不是预期的异构体产物L 1 GeP(O)Ph 2。反应1用二烷基硫代磷酸和二苯基硫代次膦酸生成的产物6a和6b含有P═S双键而不是P═O双键。
Ethylene Tetramerization: A New Route to Produce 1-Octene in Exceptionally High Selectivities
作者:Annette Bollmann、Kevin Blann、John T. Dixon、Fiona M. Hess、Esna Killian、Hulisani Maumela、David S. McGuinness、David H. Morgan、Arno Neveling、Stefanus Otto、Matthew Overett、Alexandra M. Z. Slawin、Peter Wasserscheid、Sven Kuhlmann
DOI:10.1021/ja045602n
日期:2004.11.1
producing 1-hexene and 1-octene is by oligomerization of ethylene, which yields a wide spectrum of linear alpha-olefins (LAOs). While there exists several processes for producing 1-hexene via ethylene trimerization, a similar route for the selective production of 1-octene has so far been elusive. We now, for the first time, report an unprecedented ethylene tetramerization reaction that produces 1-octene
PHOSPHACYCLE COMPOUND AND PROCESS FOR PRODUCTION THEREOF
申请人:Dow Global Technologies LLC
公开号:US20180291048A1
公开(公告)日:2018-10-11
The invention relates to oligomerization of olefins, such as ethylene, to higher olefins, such as a mixture of 1-hexene and 1-octene, using a catalyst system that comprises a) a source of chromium b) one or more activators and c) a phosphacycle-containing ligating compound. Additionally, the invention relates to a phosphacycle-containing ligating compound and a process for making said compound.
(R)- and (S)-6,6′-dimethyl- and 6,6′-dimethoxy-2,2′-diiodo-1,1′-biphenyls: Versatile intermediates for the synthesis of atropisomeric diphosphine ligands
作者:Marco Cereghetti、Wolf Arnold、Emil A. Broger、Alain Rageot
DOI:10.1016/0040-4039(96)01090-8
日期:1996.7
Starting from enantiomerically pure 6,6′-dimethyl- or 6,6′-dimethoxy-2,2′-diiodo-1,1′-biphenyls (1a or 1b) a variety of atropisomeric diphosphine ligands of defined axial chirality are directly accessible in good yields: asymmetric diphosphines of type B and the corresponding diphosphines with one (type C) or two (type D) stereogenic phosphorus atoms. Pitfalls of the lithiation/phosphination reaction