22692-62-2Relevant articles and documents
The leaving group dependence in the rates of solvolysis of 1,2-diphenylethyl system
Santhosh Kumara,Jayakumarb,Balachandranc
experimental part, p. 783 - 788 (2011/05/05)
1,2-Diphenylethyl chloride undergoes solvolysis by SN1 mechanism in aqueous organic solvents. The α-phenyl group of 1,2-diphenylethyl chloride enters into conjugation with the developing carbocationic centre. The β-phenyl group on the other hand was unable to extend its conjugation via neighbouring group participation due to steric inhibition of resonance in the formation of non-classical carbocation. 1,2-Diphenylethyl chloride thus behaves similar to 1-phenylethyl chloride in its solvolysis pattern. The solvolytic rate studies of chloride and methanesulphonate of 1,2-diphenylethyl alcohol in various aqueous organic solvents show that the dispersion observed in the Winstein- Grunwald plot is not due to a change in leaving group but due to the difference in solvation requirements of aromatic and aliphatic groups. Copyright
Palladium-catalyzed oxidative arylhalogenation of alkenes: Synthetic scope and mechanistic insights
Kalyani, Dipannita,Satterfield, Andrew D.,Sanford, Melanie S.
supporting information; experimental part, p. 8419 - 8427 (2010/08/04)
This article describes the development of a Pd-catalyzed reaction for the arylhalogenation (halogen = Cl or Br) of diverse α-olefins by oxidatively intercepting Mizoroki-Heck intermediates. These transformations afford synthetically useful 1,2- and 1,1-arylhalogenated products in good yields with good to excellent selectivities that can be modulated by changing the nature of the halogenating reagent and/or the reaction conditions. The selectivity of these reactions can be rationally tuned by (i) controlling the relative rates of oxidative functionalization versus β-hydride elimination from equilibrating PdII-alkyl species and (ii) stabilization of organometallic PdII intermediates through the formation of π-benzyl adducts. These arylhalogenations exhibit modest to excellent levels of stereoselectivity, and the key carbon-halogen bond-forming step proceeds with predominant retention of stereochemistry at carbon.
