The catalytic enantioselective [2+2] cycloaddition between quinones and fulvenes was achieved, for the first time, by the use of a chiral copper(II) complex catalyst. The transformation afforded a series of enantiomerically enriched [6,4,5]-tricyclic cyclobutane derivatives in good yields with excellent regio- and stereoselectivities. Furthermore, the [2+2] adducts could be easily converted into formal
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。
Diels-alder reactions of o-benzoquinones with 6-substituted fulvenes: Facile synthesis of 1-aryl and 1,1-diarylmethylene-4,7-ethanoindene-8,9-diones 1
3,5-Di-tert-butyl-, 4-tert-butyl- and 3-methoxy-o-benzoquinones have been shown to undergo facile thermal cycloaddition to symmetrical and unsymmetrical fulvenes to give bicyclo[2.2.2]octene diones in high yields.
Alkylation of carbonyl compounds with dialkylzirconocene complexes promoted by potassium t-butoxide
作者:Ann L. Larson、Diana L. Baker、Robert W. Towne、Daniel A. Straus
DOI:10.1016/s0040-4039(00)79419-6
日期:1991.10
Potassium t-butoxide promotes alkylation of non-enolizable ketones and aldehydes by zirconocene dialkyls. The reaction proceeds with loss of cyclopentadienide ion from the metal center.
Hetero-Diels-Alder Reaction of 3-Bromo-7-(bromomethyl)tetracyclo[5.3.1.0<sup>2,6</sup>.0<sup>4,8</sup>]undec-10(12)-ene-9,11-dione with Pentafulvenes: Facile Synthesis of Novel Polycyclic Cage Compounds Having a Pyran Ring
作者:Mangalam Nair、Beena James、E. Suresh
DOI:10.1055/s-2006-956481
日期:2006.12
The enone moiety of 3-bromo-7-(bromomethyl)tetracyclo[5.3.1.02,6.04,8]undec-10(12)-ene-9,11-dione undergoes facile hetero-Diels-Alder reaction with pentafulvenes leading to novel cage systems with pyran moiety