A New Synthesis of cis-Cyclobut-3-ene-1,2-dicarboxylic Anhydride
作者:Noëlle Gauvry、Corinne Comoy、Cyrille Lescop、François Huet
DOI:10.1055/s-1999-3441
日期:1999.4
The title compound was prepared in two steps by [2 + 2] photochemical cycloaddition between (E)-1,2-dichloroethene and maleic anhydride followed by reductive chlorine elimination with activated zinc. This safe synthetic route gave cis-cyclobut-3-ene-1,2-dicarboxylic anhydride in good overall yield and could be carried out on a multigram scale.
On the Stereoselectivity of Ring-Opening Metathesis Polymerization (ROMP) of <i>N</i>-Arylpyrrolidine-Fused Cyclobutenes with Molybdenum– and Ruthenium–Alkylidene Catalyst
[(Cy3P)2Cl2Ru═CHPh] or Schrock molybdenum carbene with monodendate alkoxy ligands [Mo(N-2,6-i-Pr2C6H3)(CHCMe2Ph)(OCMe(CF3)2] yield the corresponding polycyclobutene containing a mixture of Z- and E-double bonds. Upon diimide reduction, all these polycyclobutenes give the same tactic hydrogenated polymers, indicating that the stereochemistry at the asymmetric carbons remains the same in all these reactions. The stereoselectivities
N-芳基吡咯烷与含有外消旋双酚盐配体[Mo(N- 2,6 - i - Pr 2 C 6 H 3)(CHCMe 2 Ph)(双酚盐)的Schrock-Hoveyda催化剂稠合的环丁烯的开环易位聚合(ROMP))]给出的聚环丁烯具有均匀的立构规整度,并且在Z-构型中主要为双键。与第一代Grubbs催化剂[(CY同一基板的反应3 P)2氯2 Ru═CHPh]或施罗克钼卡宾与monodendate烷氧基配体[沫(N-2,6-我-Pr 2 ç 6 ħ 3)(CHCMe 2 Ph)(OCMe(CF 3)2 ]生成相应的含有Z-和E-双键混合物的聚环丁烯。在所有这些反应中,不对称碳原子都相同,比较了ROMP与环丁烯和降冰片烯的立体选择性,并提出了合理的机理。
Ring opening metathesis polymerization of triazole-bearing cyclobutenes: Diblock copolymer synthesis and evaluation of the effect of side group size on polymerization kinetics
作者:Jia Wei、William Trout、Yoan C. Simon、Sergio Granados-Focil
DOI:10.1002/pola.28565
日期:2017.6.1
pendant groups of varying sizes were polymerizedvia ring opening metathesispolymerization using Grubbs catalyst 2nd generation (G2). The rate of polymerization depended on the size of the pendant groups attached to the cyclobutene rings, with longer side‐chains producing slower polymerization rates and narrower molecular weight distributions. The polymerization of these new molecules proceeded with
New approaches for the synthesis of erythrinan alkaloids
作者:Fengzhi Zhang、Nigel S. Simpkins、Alexander J. Blake
DOI:10.1039/b900189a
日期:——
A concise asymmetric total synthesis of (+)-erysotramidine is described, using chiral base desymmetrisation of a meso-imide, N-acyliminium addition, retro-Diels–Alder cycloaddition and radical cyclisation as the key steps. A related route, starting from a cyclobutene-fused imide, was explored, and established a novel construction of the Erythrina alkaloid skeleton using a key ring-opening/ring-closing