2010
DOI: 10.1021/ma101375v
|View full text |Cite
|
Sign up to set email alerts
|

Z-Selective and Syndioselective Ring-Opening Metathesis Polymerization (ROMP) Initiated by Monoaryloxidepyrrolide (MAP) Catalysts

Abstract: We report the Z-selective and syndioselective polymerization of 2,3-bis(trifluoromethyl)bicyclo[2.2.1]hepta-2,5-diene (NBDF6) and 3-methyl-3-phenylcyclopropene (MPCP) by monoaryloxide monopyrrolide imido alkylidene (MAP) catalysts of Mo. The mechanism of polymerization with syn-Mo(NAd)(CHCMe 2 Ph)(Pyr)(OHIPT) (1; Ad = 1-adamantyl, OHIPT = O-2,6-(2,4,6-i-Pr 3 C 6 H 2 ) 2 C 6 H 3 ) as the initiator is proposed to consist of addition of monomer to the syn initiator to yield a syn first insertion product and propa… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
1
1

Citation Types

0
68
0

Year Published

2014
2014
2015
2015

Publication Types

Select...
5
4

Relationship

3
6

Authors

Journals

citations
Cited by 115 publications
(68 citation statements)
references
References 42 publications
0
68
0
Order By: Relevance
“…6 In the last several years we have reported monoaryloxide pyrrolide (MAP) catalysts for the Z-selective metathesis reactions of disubstituted olefins, 7 an example being Mo(N-1-adamantyl)(CHCMe 2 Ph)(Pyr)(OHIPT) (OHIPT = O-2,6-(2,4,6-i-Pr 3 C 6 H 2 ) 2 C 6 H 3 ). 8 The theory is to limit the substitution pattern in the intermediate TBP metallacyclobutane to one in which any single substituent on a metallacycle carbon atom points away from a large axial aryloxide ligand and toward a relatively small X ligand (imido or oxo (W only); Figure 2). An "inversion" of the roles of a "large" aryloxide and a "small" imido group would be another way to limit the formation of metallacyclobutane intermediates to those with substituents all on one side and at the same time could limit formation of syn alkylidene isomers in favor of anti alkylidene isomers.…”
mentioning
confidence: 99%
“…6 In the last several years we have reported monoaryloxide pyrrolide (MAP) catalysts for the Z-selective metathesis reactions of disubstituted olefins, 7 an example being Mo(N-1-adamantyl)(CHCMe 2 Ph)(Pyr)(OHIPT) (OHIPT = O-2,6-(2,4,6-i-Pr 3 C 6 H 2 ) 2 C 6 H 3 ). 8 The theory is to limit the substitution pattern in the intermediate TBP metallacyclobutane to one in which any single substituent on a metallacycle carbon atom points away from a large axial aryloxide ligand and toward a relatively small X ligand (imido or oxo (W only); Figure 2). An "inversion" of the roles of a "large" aryloxide and a "small" imido group would be another way to limit the formation of metallacyclobutane intermediates to those with substituents all on one side and at the same time could limit formation of syn alkylidene isomers in favor of anti alkylidene isomers.…”
mentioning
confidence: 99%
“…While complexes 3a, 3b, 4, 5, 8, and 9 contain two triflate groups, compound 6 contains two different anionic ligands, i.e., one triflate and one hexafluro-2-propoxide group. As found for MAP-type catalysts [14,[25][26][27][28][29][30][31][32][33][34][35][36][37][38][39], no ligand scrambling is observed. Cationic 7 is unique: it represents the first cationic Mo imido alkylidene catalyst that displays substantial olefin metathesis reactivity (vide infra).…”
Section: Introductionmentioning
confidence: 67%
“…38 Enantiomorphic site control of polymer formation is complemented by the more recent development of MAP initiators (e.g., 1, 3, or 4) that promote formation of cis C=C bonds (vide supra) and in the process, formation of cis,syndiotactic polymers as a consequence of the chirality at the metal switching with each insertion of monomer into the M=C bond (stereogenic metal control). 39 Hydrogenation of pure cis,isotactic or cis,syndiotactic polymers made from norbornene 40 or dicyclopentadiene 41 yields isotactic or syndiotactic hydrocarbon polymers that are crystalline, high melting, relatively stable to oxygen, and therefore of commercial value. Tungsten oxo alkylidene complexes, especially when activated with B(C 6 F 5 ) 3 , recently have been found to polymerize norbornenes and norbornadienes that are difficult to polymerize stereoselectively, or in some cases, to polymerize at all at 22 °C with traditional Mo or W imido alkylidene initiators.…”
Section: Stereospecific Polymerizationmentioning
confidence: 99%