在CHCl 3,CH 3 CN或AcOH中,苯硒基氯(PhSeCl),溴化物(PhSeBr)和乙酸盐(PhSeOAc),2-硝基苯硫基氯(NO 2 C 6 H 4 SCl)和2,4-二硝基苯硫基氯(将(NO 2)2 C 6 H 3 SCl)加入到双环[2.2.1]庚-5-烯-2-酮(5)中。具有完全的立体和区域选择性的反时尚,得到加合物20–24,其中氯化物,溴化物或乙酰氧基取代基(X)占据C(6)的内位,而Se或S取代基(E)处于外显子在C(5)位置上,添加5 +(NO 2)2 C 6 H 3 SCl 24伴随有(1 RS,2 RS)-2-(2,4-二硝基苯硫基)环戊-3-烯的形成-1-乙酸(25)。后者是含LiClO 4的AcOH中的主要产物。在双环[2.2.2] oct-5-en-2-one(6)中添加PhSeCl和PhSeBr的立体选择性较低(exo与亲电子攻击的内模的比例约为3:
Generation of endo-6-(trimethylsilyl)bicyclo[2.2.1] hept-2-yl carbene and syn-6-(trimethylsilyl)bicycle[2.2.2]oct-2-yl carbene leads to preferential 1,3-migration of the trimethylsilyl group to the carbenic center, while anti-6-(trimethylsilyl)bicycle[2.2.2]oct-2-yl carbene gives preferential migration of the trimethylsilyl-activated hydrogen atom.
The Bicyclo[2.2.2]octyl Carbene System as a Probe for Migratory Aptitudes of Hydrogen to Carbenic Centers
作者:Xavier Creary、Mark A. Butchko
DOI:10.1021/ja002407+
日期:2001.2.1
A series of tosylhydrazone derivatives of exo-6-substituted bicylo[2.2.2]octan-2-ones have been prepared. Thermal decomposition of the sodiumsalts of these tosylhydrazones gives carbene-derived products from 1,3-migration of either the C6 hydrogen (perturbed) or the C7 hydrogen (unperturbed), along with smaller amounts of alkenes derived from 1,2-hydrogen migration. The exo-6-substituent strongly
The Carbonyl Group as Homoconjugated Electron-Releasing Substituent. Regioselective electrophilic additions at bicyclo[2.2.1]hept-5-en-2-one, bicyclo[2.2.2]oct-5-en-2-one, and derivatives
作者:Pierre-Alain Carrupt、Pierre Vogel
DOI:10.1002/hlca.19890720519
日期:1989.8.9
NO2C6H4SCl, and (NO2)2C6H3SCl to 2-(bicyclo[2.2.1]hept-5-en-2-ylidene)propanedinitrile (49) were not regioselective, showing that a dicyanomethylidene function is not like a carbonyl function when homoconjugated with a π system. The results are in agreement with predictions based on MO calculations suggesting that a carbonylgrouphomoconjugated with an electron-deficient centre can behave as an electron-donating
在CHCl 3,CH 3 CN或AcOH中,苯硒基氯(PhSeCl),溴化物(PhSeBr)和乙酸盐(PhSeOAc),2-硝基苯硫基氯(NO 2 C 6 H 4 SCl)和2,4-二硝基苯硫基氯(将(NO 2)2 C 6 H 3 SCl)加入到双环[2.2.1]庚-5-烯-2-酮(5)中。具有完全的立体和区域选择性的反时尚,得到加合物20–24,其中氯化物,溴化物或乙酰氧基取代基(X)占据C(6)的内位,而Se或S取代基(E)处于外显子在C(5)位置上,添加5 +(NO 2)2 C 6 H 3 SCl 24伴随有(1 RS,2 RS)-2-(2,4-二硝基苯硫基)环戊-3-烯的形成-1-乙酸(25)。后者是含LiClO 4的AcOH中的主要产物。在双环[2.2.2] oct-5-en-2-one(6)中添加PhSeCl和PhSeBr的立体选择性较低(exo与亲电子攻击的内模的比例约为3: