Unusual endoperoxide isomerizations: a convenient entry into 2-vinyl-2-cyclopentenones from saturated fulvene endoperoxides
摘要:
An unusual peroxide base-promoted isomerization is uncovered. Saturated endoperoxides derived from fulvenes give rise to 2-vinyl-2-cyclopentenones upon treatment with DBU in CH2CL2 in a one-pot reaction. This methodology is applied to a convenient synthesis of dihydrojasmone. Moreover, functional groups placed on the side chain at C-6 participate in the base-catalyzed isomerizations via conjugate attack at the enone moiety to give 2-cyclopentenones carrying oxygen heterocycles at C-2. (c) 2006 Elsevier Ltd. All rights reserved.
Reaction of dicyclopentadienylyttrium chloride with aldehydes and ketones. A novel cleavage reaction of CpY π-bond
作者:Changtao Qian、Aineng Qiu
DOI:10.1016/s0040-4039(00)88478-6
日期:1988.1
Dicyclopentadienylytrrium chloride reacts with aldehydes and ketones at 80°C in DME, generating fulvenes in excellent yields, while at lower temperature affording, after hydrolysis, cyclopentadienyl substituted alcohols.
Expeditious synthesis of N-bridged heterocycles via dipolar cycloaddition of pentafulvenes with 3-oxidopyridinium betaines
作者:Jinesh M. Kuthanapillil、Sreeja Thulasi、Rani Rajan、K. Syam Krishnan、E. Suresh、K.V. Radhakrishnan
DOI:10.1016/j.tet.2010.11.084
日期:2011.2
A new and highly versatile approach towards the synthesis of bicyclo[6.3.0]undecanes and bicyclo[5.3.0]decanes was accomplished. The methodology adopted involved [6+3] and [3+2] cycloaddition reactions of pentafulvenes with 3-oxidopyridinium betaines generated either by the action of a base on the pyridinium salt or thermally from pyridinium betaine dimer. These well-functionalized bicyclo[6.3.0]undecanes
ABSTRACT An efficient protocol for the Lewis acid catalyzed three-component aza-Diels-Alder reaction of pentafulvenes as dienophile has been developed. Cyclopentene fused tetrahydroquinolines were formed in good yields with excellent diastereoselectivities. The method was extended to spiro[2,4]hepta-4,6-diene, by which 3,4-dihydroquinoline derivatives were obtained. The aromatization of cycloadducts
C1-Bridged fluorenylidene cyclopentadienylidene complexes of the type (C13H8–CR1R2–C5H3R)ZrCl2 (R1, R2=alkyl, phenyl, alkenyl; R=H, alkyl, alkenyl, substituted silyl) as catalyst precursors for the polymerization of ethylene and propylene
作者:Helmut G. Alt、Michael Jung
DOI:10.1016/s0022-328x(98)00740-2
日期:1998.10
The synthesis and characterization of 14 new C1-bridged fluorenylidene cyclopentadienylidene complexes of zirconium is described. After activation with methylaluminoxane (MAO), these metallocene complexes can be used for the polymerization of ethylene and propylene. Various substituents in the bridge and in position 3 of the cyclopentadienylidene ligand have a strong influence on the activity of the
Broad Scope [4 + 2] Cycloaddition of <i>o</i>-Carboryne with Pentafulvenes Using 1-Li-2-OTf-<i>o</i>-C<sub>2</sub>B<sub>10</sub>H<sub>10</sub> as Precursor
作者:Jie Zhang、Zaozao Qiu、Zuowei Xie
DOI:10.1021/acs.organomet.7b00574
日期:2017.10.9
from 1-Li-2-OTf-o-C2B10H10 undergoes an efficient [4 + 2] cycloaddition with pentafulvenes at room temperature to give a series of carboranonorbornenes in good to high isolated yields. This reaction is compatible with many functional groups and has a very broad substrate scope from 6-mono- to 6,6′-disubstituted pentafulvenes and from alkyl to aryl substituents. Further transformations of the resultant
从1-Li-2-OTf- o -C 2 B 10 H 10原位生成的邻-碳硼烷(1,2-脱氢-邻-甲硼烷)在室温下进行有效的[4 + 2]环戊五烯加成反应,得到一系列高或高分离产率的碳硼烷降冰片烯。该反应与许多官能团相容,并且具有非常宽的底物范围,从6-单-至6,6'-二取代的五氟戊烯和从烷基至芳基取代基。已经对所得的[4 + 2]环加成产物进行了进一步的转化,从而提供了各种多功能的邻氨基甲酸酯。