作者:Eckehard V. Dehmlow、Manfred Lissel、Joachim Heider
DOI:10.1016/0040-4020(77)80121-x
日期:1977.1
claims in the literature no optical induction is observed in CX2 additions. These results support once more the intermediacy of free CX2. CBr2 is more reactive and electrophilic than CCl2 under phase transfer catalysis conditions, again contrary to literature claims. An example of a differing mode of reaction of chloroform and bromoform is given.
The reaction of 2,2-dibromo-l-methyl-cyclopropanecarbonitrile (1) with i-PrMgCl in Et2O/CH2Cl2 provides the cis-magnesium-carbenoid (2), which reacts with high retention of configuration with various electrophiles. If E = SPh, a stereoselective generation of a quaternary center via a sequential Br/Mg- and sulfoxide/Mg-exchange can be achieved.
Reduction of gem-dibromides with diethyl phosphite