Chemoselective Cobalt(I)-Catalyzed Cyclotrimerization of (Un)Symmetrical 1,3-Butadiynes for the Synthesis of 1,2,4-Regioisomers
作者:Sebastian M. Weber、Gerhard Hilt
DOI:10.1021/acs.orglett.9b01281
日期:2019.6.7
The cobalt(I)-catalyzed cyclotrimerization of (un)symmetrical 1,4-disubstituted 1,3-butadiynes is presented. In the case of unsymmetrical 1,3-butadiynes, this reaction can generate eight 1,2,4-substituted and four 1,3,5-substituted isomers. A single 1,2,4-substituted isomer was formed in excellent yields (up to 99%) and exclusive regioselectivities (>99:1) when symmetrical or a 1,3-butadiyne with an
Regiospecific Formation and Unusual Optical Properties of 2,5-Bis(arylethynyl)rhodacyclopentadienes: A New Class of Luminescent Organometallics
作者:Andreas Steffen、Richard M. Ward、Meng Guan Tay、Robert M. Edkins、Fabian Seeler、Magda van Leeuwen、Lars-Olof Pålsson、Andrew Beeby、Andrei S. Batsanov、Judith A. K. Howard、Todd B. Marder
DOI:10.1002/chem.201304068
日期:2014.3.24
their chloro analogues by reaction with HCl etherate. The rhodacycles thus obtained are stable to air and moisture in the solid state and the acceptor‐substituted compounds are even stable to air and moisture in solution. The photophysical properties of the rhodacyclopentadienes are highly unusual in that they exhibit, exclusively, fluorescence between 500–800 nm from the S1 state, with quantum yields of
通过一个罕见的1,4-(对-R-苯基)-1,3-丁二炔(RH,Me,OMe, SME,NME 2,CF 3,CO 2 Me中,CN,NO 2,-CC-(p -C 6 H ^ 4 nHex中2),-CC (p -C 6 H ^ 4 CO 2 10月的))在[RHX(PME 3)4 ](1)(X =-CC 森达3(一),-CC-(p -C 6 H ^ 4 NME 2)(b),-CC CC (p -C 6 H ^ 4 NPH 2)(ç)或 CC p -C 6 H ^ 4 -CC (p -C 6 H ^ 4 -N(C 6 H ^ 13)2)} ...(d)或Me(Ë)),仅给出2,5-双(芳基乙炔基)异构体。通过与HCl醚化物反应,在赤道面上带有甲基配体的铑环戊二烯(化合物1e)已被转化为它们的氯类似物。由此获得的铑环在固态下对空气和水分稳定
Rhodium-catalyzed electrochemical [2 + 2 + 2] cyclotrimerization of 1,3-butadiynes toward hexasubstituted arenes
作者:Mu-Jia Luo、Gui-Fen Lv、Jing-Hao Qin、Chong-Hui Xu、Yang Li、Jin-Heng Li
DOI:10.1039/d3gc02831c
日期:——
attractive method for the construction of diverse organic frameworks because it obviates the use of chemical redox reagents. Herein, we report an elegant rhodium-catalyzed electrochemical [2 + 2 + 2] cyclotrimerization of 1,3-butadiynes for the regioselective synthesis of structurally diverse hexasubstituted arenes in an undivided cell. This methodology features excellent regioselectivity, good functional
The hydrosilatation of Pr-n-C=C-Pr-n, Ph-C=C-Ph, Me3Si-C=C-SiMe3, Ph-C=C-C=C-Ph, Bu-t-C=C-C=C-Bu-t and Me3Si-C=C-C=C-SiMe3 with Ph2SiH2, PhMe2SiH and Et3SiH in the presence of L2Ni(0)-butadiyne catalysts [L = Ph3P, (o-Tol-O)(3)P] has been studied. In all cases the hydrosilylation proceeds via a cis-addition of the silanes. The disubstituted alkynes (Pr-n-C=C-Pr-n, Ph-C=C-Ph) give hydrosilylated ethene, butadiene and hexatriene derivatives as well as non-hydrosilylated benzene derivatives. In the case of Me3Si-C=C-SiMe3 no reaction was observed. The hydrosilylation of disubstituted butadiynes proceeds stepwise to give at first the 1,2-adducts. In dependence on the butadiynes either a 1,4-addition (Bu-t-C=C-C=C-Bu-t, Me3Si-C=C-C=C-SiMe3) to the corresponding allene derivatives (11, 13, 15) or a 3,4-addition (Ph-C=C-C=C-Ph) to the 1,3-butadiene 19 takes place subsequently. The reaction products were characterized by mass spectrometry, IR and NMR spectroscopy.