Method for the Isomerisation of Transition Metal Complexes Containing Cyclometallated, Carbene Ligands
申请人:Molt Oliver
公开号:US20080200686A1
公开(公告)日:2008-08-21
The present invention relates to a process for converting an isomerically pure compound C
1
of the formula I
or a mixture M
1
comprising C
1
into an isomeric compound C
2
of the formula I which is different from C
1
or a mixture M
2
comprising C
2
, where the variables have the following meanings:
n is 2 or 3;
M is Pd or Pt, in each case in the formal oxidation state +II, when n is 2;
and is Ru, Os, Co, Rh or Ir, in each case in the formal oxidation state +III, when n is 3;
Do is a donor atom selected from the group consisting of N, O, S and P;
r is 1 when Do is N or P, and is 0 when Do is O or S;
Y
1
, Y
2
are each, independently of one another, hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, alkyloxy, aryloxy, alkylthio, arylthio, alkylcarbonyl, arylcarbonyl, carboxyl, alkyloxycarbonyl, aryloxycarbonyl, hydroxysulfonyl, alkyloxysulfonyl, aryloxysulfonyl, halogen, CN, CHO, NO
2
or NO,
or
Y
1
and Y
2
together with the carbon atom to which they are bound form a six-membered aromatic ring which may comprise one or two nitrogen atoms and
may optionally be fused with a further, optionally fused and optionally hetero-atom-comprising ring;
Y
3
is alkyl, alkenyl, alkynyl, aryl or heteroaryl;
A is a bridge having three or four atoms of which one or two atoms may be heteroatoms and the remaining atoms are carbon atoms, so that the group
forms a five- or six-membered heteroaromatic ring or benzene ring which may optionally be substituted by substituents selected from the group consisting of alkyl, alkenyl, alkynyl, aryl, heteroaryl, alkyloxy, aryloxy, alkylthio, arylthio, alkylcarbonyl, arylcarbonyl, carboxyl, alkyloxycarbonyl, aryloxycarbonyl, hydroxysulfonyl, alkyloxysulfonyl, aryloxysulfonyl, halogen, CN, CHO, NO
2
and NO and may optionally be fused with a further, optionally heteroatom-comprising ring which may likewise be fused and substituted by substituents selected from the group consisting of alkyl, alkenyl, alkynyl, aryl, heteroaryl, alkyloxy, aryloxy, alkylthio, arylthio, alkylcarbonyl, arylcarbonyl, carboxyl, alkyloxycarbonyl, aryloxycarbonyl, hydroxysulfonyl, alkyloxysulfonyl, aryloxysulfonyl, halogen, CN, CHO, NO
2
and NO;
which comprises allowing a Brönsted acid or a mixture of Brönsted acids to act on C
1
or M
1
in the presence of a solvent or solvent mixture at a temperature of from 0° C. to the boiling point of the solvent or the solvent mixture, with the proviso that
a) the formation of C
2
from C
1
occurs under the conditions of the process
and
b) when both M
1
and M
2
are mixtures comprising C
1
and C2, the respective isomer ratios of C
1
and C
2
in the mixtures M
1
and M
2
are different from one another.