Synthesis of a stereoblock polyketone through ancillary ligand exchange

Journal of the American Chemical Society

Volumn 118, Issue 30, 1996, Pages 7219-7220

  Brookhart, M ^a   Wagner, Mark I ^a  

^a UNIVERSITY OF NORTH CAROLINA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CATALYSIS; KETONES; PHYSICAL CHEMISTRY; POLYMERIZATION; SYNTHESIS (CHEMICAL);

ANCILLARY LIGAND EXCHANGE; STEREOBLOCK POLYKETONES;

BLOCK COPOLYMERS;

KETONE; POLYMER;

ARTICLE; DRUG SYNTHESIS; NUCLEAR MAGNETIC RESONANCE; POLYMERIZATION;

EID: 9344220459     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja9610141     Document Type: Article

References (23)

1. (a) Waymouth, R. M.; Coates, G. W. Science 1995, 267, 217.
2. (b) Waymouth, R. M.; Hauptman, E.; Ziller, J. W. J. Am. Chem. Soc. 1995, 117, 11586.
3. Chien, J. C. W.; Mallin, D. T.; Rausch, M. D.; Lin, Y. G.; Dong, S. J. Am. Chem. Soc. 1990, 112, 2030.
4. Chien, J. C. W.; et al. J. Am. Chem. Soc. 1991, 113, 8569.
5. Collette, J. W.; et al. Macromolecules 1989, 22, 3851.
6. Collette, J. W.; Ovenall, D. W.; Buck, W. H.; Ferguson, R. C. Macromolecules 1989, 22, 3858.
7. Ligand variation has been used to control cis versus trans structures in 1,4-polybutadiene: Teyssie, P.; Dawans, F.; Durand, J. P. J. Polym. Sci., Part A-1 1970, 8, 979.
8. (a) Brookhart, M.; Rix, F. C.; DeSimone, J. M.; Barborak, J. C. J. Am. Chem. Soc. 1992, 114, 5894, For earlier reports of Pd(II)-catalyzed CO/styrene copolymerizations, see:
9. (b) Drent, E. Eur. Pat. Appl, 229,408; Chem. Abstr. 1988, 108, 6617.
10. (c) Corradini, P.; De Rosa, A.; Panunzi, A.; Pino, P. Chimia 1990, 44, 52.
11. 25D -536○: Brookhart, M.; Wagner, M. I.; Balavoine, G. G. A.; Haddou, H. A. J. Am. Chem. Soc. 1994, 116, 3641. See also:
12. (b) Bartolini, S.; Carfagna, C.; Musco, A. Macromol. Rapid. Commun. 1995, 6, 9.
13. Atactic polymer was produced through epimerization of syndiotactic polymer in aqueous base.
14. n f r the stereoblock polymer is 1.4, The GPC trace is monomodal with a small, low molecular weight tail from slight catalyst decomposition. The GPC traces are contained in the supporting information.
15. Polymerization rates from the achiral, syndiospecific catalysts are approximately 10 times faster than those of isospecific polymerizations.
16. A racemic mixture of chiral catalysts I-2 and I-3 produces isotactic copolymer with no optical activity.
17. Consiglio has reported that enantioselectivity in similar systems is determined by both the chiral ligand and the last inserted monomer unit: Consiglio, G.; Sperrle, M. J. Am. Chem. Soc. 1995, 117, 12130.
18. +. See ref 7a.
19. The pairs of diastereomers 7,10 and 5,8 are comparable to matched and mismatched pairs, respectively, in double asymmetric synthesis: Masamune. S.; Choy, W.; Peterson, J. S.; Sita, L. R. Angew. Chem., Int. Ed. Engl. 1985, 24, 1.
20. 2 solution produces 12 in situ. The synthesis, isolation, and purification of 12 are contained in the supporting information.
21. Similar behavior has been observed in Rh systems with bidentate and terdentate nitrogen ligands: (a) Nishiyama, H.; Kondo, M.; Nakamura, T.; Itoh, K. Organometallics 1990, 10, 500. (b) Brunner, H.; Brandl, P. Tetrahedron: Asymmetry 1991, 2, 919.
22. Similar behavior has been observed in Rh systems with bidentate and terdentate nitrogen ligands: (a) Nishiyama, H.; Kondo, M.; Nakamura, T.; Itoh, K. Organometallics 1990, 10, 500. (b) Brunner, H.; Brandl, P. Tetrahedron: Asymmetry 1991, 2, 919.
23. 1 bound ligand leads to topomerization of gem dimethyls on the same ligand.