The Crossed [2+2] Cycloaddition of 1-Phenylcyclopropene and 1-Bromo-2-phenylcyclopropene
摘要:
1-Bromo-2-phenylcyclopropene (2) underwent [2+2] dimerization to generate 1,2-dibromo-4,5-diphenyltricyclo[3.1.0.0(2,4)]hexane (5), which was heated to form 1,2-dibromo-4,5-diphenyleyclohexa-1,4-diene (6) followed by oxidation to yield 4',5'-dibromo-o-terphenyl (7). o-Terphenyl 7 could be synthesized in one-pot reactions from 1, 1,2-tribromocyclopropane (3). When cyclopropane 3 was treated with 1.5 equiv of methyllithium followed by slowly adding the proton source, crossed [2+2] adduct 8 was isolated in 40% yield. Compound 8 was heated and oxidated to produce 4'-bromo-o-terphenyl (11).
Rapid access to cyclopentadiene derivatives through gold-catalyzed cycloisomerization of ynamides with cyclopropenes by preferential activation of alkenes over alkynes
Cyclopropenylcarbinol Derivatives as New Versatile Intermediates in Organic Synthesis: Application to the Formation of Enantiomerically Pure Alkylidenecyclopropane Derivatives
作者:Samah Simaan、Ahmad Masarwa、Elinor Zohar、Amnon Stanger、Philippe Bertus、Ilan Marek
DOI:10.1002/chem.200901074
日期:2009.8.24
The copper‐catalyzed carbomagnesiation (or hydrometalation) reaction of chiralcyclopropenylcarbinolderivatives, obtained by means of a kinetic resolution of secondary allylic alcohols, leads to an easy and straightforward preparation of enantiomericallypurealkylidenecyclopropanederivatives. The reaction mechanism is composed of a syn‐carbometalation followed by a syn‐elimination reaction. To gain
gem-Dihalocyclopropane formation by iron/copper activation of tetrahalomethanes in the presence of nucleophilic olefins. Evidence for a carbene pathway
作者:Eric Léonel、Michael Lejaye、Sylvain Oudeyer、Jean Paul Paugam、Jean-Yves Nédélec
DOI:10.1016/j.tetlet.2004.01.124
日期:2004.3
The activation of CBr4 and CCl4 by a bimetallic iron/copper couple in acetonitrile is a new, inexpensive, nontoxic and efficient procedure for gem-dibromo- and gem-dichloromethylenation of nucleophilic alkenes. This new route to gem-dihalocyclopropanes involves dihalocarbene species.
Regioselective Carbon–Carbon Bond Cleavage in the Oxidation of Cyclopropenylcarbinols
作者:Ahmad Basheer、Masaaki Mishima、Ilan Marek
DOI:10.1021/ol201581c
日期:2011.8.5
The strained double bond of cyclopropenylcarbinols undergoes a facile oxidation reaction to lead to unsaturated carbonyl derivatives. The distribution of the formed products depends on the relative stability of carbon-centered radical species, and the Sharpless kinetic resolution leads to enantiomerically pure Baylis–Hillman enal adducts.
Cyclopropenyllithiums as a new source of 1,1-bismetalated cyclopropyl derivatives
作者:Anat Levin、Ilan Marek
DOI:10.1039/b807635a
日期:——
The allylmetalation of functionalised cyclopropenyllithium derivatives leads to the unique formation of 1,1-bismetalated cyclopropyl species that react selectively with different electrophiles.
Synthesis of functionalized cyclopropylboronic esters based on a 1,2-metallate rearrangement of cyclopropenylboronate
作者:Haruki Mizoguchi、Masaya Seriu、Akira Sakakura
DOI:10.1039/d0cc07134j
日期:——
functionalized β-selenocyclopropylboronic ester using the 1,2-metallate rearrangement of a boron ate-complex has been developed. Treatment of an in situ-generated cyclopropenylboronic ester ate-complex with phenylselenenyl chloride triggered stereospecific rearrangement to produce functionalized cyclopropanes. DFT calculations for 1,2-metallate rearrangement suggested that the reaction proceeds through