ISSN:
0899-0042
Keywords:
enantioselectivity
;
carbonylation
;
hydroformylation
;
hydroalkoxycarbonylation
;
para-substitution
;
2-phenylpropene
;
platinum catalyst
;
palladium catalyst
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The enantioselective hydroformylation catalyzed by [(R,R)-Diop]Pt(SnCl3)Cl7 and the enantioselective hydroisopropoxycarbonylation catalyzed by [(R,R)-Diop]PdCl28 or by [(R,R)-Diop-dbp]PdCl29 of some para-substituted 2-phenylpropenes (para substituents = NO2, H, CH3O, Cl, CF3) was investigated in order to recognize possible electronic influences on the regioselectivity and on the enantioface selection which take place in such carbonylation reactions. The catalytic systems used gave no carbonylation products when the nitro compound was the substrate. 7 and 8 show similar regioselectivities, the less branched isomer being exclusively formed for all substrates except p-methoxy-2-phenylpropene which gave small amounts of the alternative regioisomer. The enantioselectivity depends on the σp effect of the substituent in both cases; the differences are, however, rather small and the trend is opposite in the two cases. The regioselectivity displayed by 9 is still in favour of the less branched isomer but it is high only in the case of p-trifluoromethyl-2-phenylpropene. Larger differences with respect to the other catalytic systems were also observed for enantioselectivity but the trend for both regioselectivity and enantioselectivity is not linear.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chir.530030420
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