radical adds to an unactivated alkene to smoothly form a new carbon radical, followed by a 1,5‐hydrogen atom‐transfer process, the rate‐limiting step, generating a more stable benzylic radical. The reduction of the benzylic radicals by an IrII species generates the corresponding benzylic carbanions as the key intermediates, which further undergo nucleophilic attack with CO2 to generate carboxylates.
Preparation of difunctional initiators for anionic polymerization
申请人:Xerox Corporation
公开号:US05487848A1
公开(公告)日:1996-01-30
Processes for preparing a polymerization initiator precursor compound are disclosed wherein a first process involves dimerizing a halogen-diarylpropane compound to form a tetraarylhexane compound. A second process involves reacting a diaryl-propanol compound with a halogen-diarylpropane compound to form a bis(diaryl-propyl) ether compound. A third process involves reacting a halogen-diarylpropane compound with allyl halogen to form a diaryl-hexene compound.
Mechanistic pathways in phosphate ester photochemistry
作者:Richard S. Givens、Rominder Singh
DOI:10.1016/0040-4039(91)85027-3
日期:1991.11
Initial bond breaking processes (homolysis vs heterolysis) of phosphateester photosolvolysis were probed by chemically trapping the reactive intermediates with a tethered 5-hexenyl group. The resulting mechanistic picture is a blend of homolytic and heterolytic pathways, where the heterolytic cleavage is dominant.
carboxylation of unactivated alkenes with CO2•− has never been reported. Here we report visible-light photocatalytic di- and hydro-carboxylation of unactivated alkenes with CO2. In contrast to previous reports limited to activated alkenes, diverse unactivated aliphatic alkenes undergo selective carboxylations to give carboxylic acids, dicarboxylic acids and unnatural α-amino acid derivatives in moderate to good