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The enantioselective copolymerisation of allylbenzene, 1‐allyl‐4‐(trifluoromethyl)benzene, and 1‐allyl‐4‐methoxybenzene with carbon monoxide
Author(s) -
Benedetto Silvia Di,
Consiglio Giambattista
Publication year - 1997
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19970800719
Subject(s) - chemistry , tetrahydrofuran , trifluoromethyl , copolymer , methylene , enantioselective synthesis , chirality (physics) , phosphine , medicinal chemistry , carbon monoxide , polymer chemistry , catalysis , benzene , organic chemistry , solvent , alkyl , polymer , chiral symmetry breaking , physics , quantum mechanics , nambu–jona lasinio model , quark
The olefins mentioned in the title were copolymerized with CO in the presence of palladium catalysts modified with dicyclohexyl{( R )‐1‐[( S )‐2‐(diphenylphosphino)ferrocenyl]ethyl}phosphine. Productivities up to 95 g/(gPd · h) were achieved. The obtained copolymers were recovered in the pure, regio‐ und stereoregular polyketone structures 3 . The isotactic poly[2‐benzyl‐1‐oxopropane‐1,3‐diyl] ( 3a ) and its analogues 3b , c were found to isomerize to the corresponding spirocyclic poly[3‐(arylmethyl)tetrahydrofuran‐2,2‐5,5‐tetrayl‐2‐oxy‐2‐methylene]s 4 in a suspension in CHC13, thus indicating that the spiroketal structure is thermodynamically the most stable for these copolymers. However, the atactic material did not undergo any structural transformation. These results show that regularity at the centers of chirality in the main chain is a prerequisite for the conversion of the polyketone to the spiroketal structure.