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Reaction mechanism of transmetalation between tetraorganostannanes and platinum(II) aryltriflate complexes. Mechanistic model for stille couplings

Nilsson, Patrik LU ; Puxty, G and Wendt, Ola LU (2006) In Organometallics 25(5). p.1285-1292
Abstract
The complexes trans-[PtPh(OTf)(PMe2Ph)(2)] (1) and trans- [PtPh(OTf)(PPh3)(2)] (4) were synthesized from the corresponding chloro complexes in moderate yields. Complex I is slowly hydrolyzed in solution, giving the dinuclear hydroxo-bridged complex [Pt(mu-OH)(PMe2Ph)(2)](2)(CF3SO3)(2) (6), which was characterized by X-ray crystallography. In solution I and 4 undergo fast solvolysis to give the corresponding solvento cations. The reactivities of 1 and 4 with Me3SnPh were investigated in different solvents, and with 1 two products, trans- [PtPh2(PMe2Ph)(2)] (8) and cis-[PtPh2(PMe2Ph)(2)] (9), were always formed simultaneously. In THF an intermediate, trans- [PtPhMe(PMe2Ph)(2)] (14), was characterized on the path to 9. The kinetics for these... (More)
The complexes trans-[PtPh(OTf)(PMe2Ph)(2)] (1) and trans- [PtPh(OTf)(PPh3)(2)] (4) were synthesized from the corresponding chloro complexes in moderate yields. Complex I is slowly hydrolyzed in solution, giving the dinuclear hydroxo-bridged complex [Pt(mu-OH)(PMe2Ph)(2)](2)(CF3SO3)(2) (6), which was characterized by X-ray crystallography. In solution I and 4 undergo fast solvolysis to give the corresponding solvento cations. The reactivities of 1 and 4 with Me3SnPh were investigated in different solvents, and with 1 two products, trans- [PtPh2(PMe2Ph)(2)] (8) and cis-[PtPh2(PMe2Ph)(2)] (9), were always formed simultaneously. In THF an intermediate, trans- [PtPhMe(PMe2Ph)(2)] (14), was characterized on the path to 9. The kinetics for these reactions were evaluated numerically, and on the basis of rate laws, activation parameters, and reactivity trends a mechanism involving parallel equilibria to 8 and 9 with associative activation in all steps is proposed. In this mechanism the initial attack always takes place trans to the phenyl group, giving 8 and 14, respectively, via an open transition state. In a subsequent reaction, 14 reacts with another molecule of stannane, giving 9 as the final product via a cyclic transition state. Complex 4 gives exclusive formation of cis products: cis-[PtPhMe(PPh3)2] (12) and cis-[PtPh2(PPh3)2] (13). These results are discussed in relation to the reaction mechanism of the transmetalation step in the Stille reaction. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Organometallics
volume
25
issue
5
pages
1285 - 1292
publisher
The American Chemical Society (ACS)
external identifiers
  • wos:000235691500027
  • scopus:33644986119
ISSN
1520-6041
DOI
10.1021/om051021a
language
English
LU publication?
yes
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The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Organic chemistry (S/LTH) (011001240), Department of Chemistry (011001220)
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1b623bd5-3f16-4451-94ac-936ed1d2485f (old id 416671)
date added to LUP
2016-04-01 12:36:05
date last changed
2020-01-12 10:07:53
@article{1b623bd5-3f16-4451-94ac-936ed1d2485f,
  abstract     = {The complexes trans-[PtPh(OTf)(PMe2Ph)(2)] (1) and trans- [PtPh(OTf)(PPh3)(2)] (4) were synthesized from the corresponding chloro complexes in moderate yields. Complex I is slowly hydrolyzed in solution, giving the dinuclear hydroxo-bridged complex [Pt(mu-OH)(PMe2Ph)(2)](2)(CF3SO3)(2) (6), which was characterized by X-ray crystallography. In solution I and 4 undergo fast solvolysis to give the corresponding solvento cations. The reactivities of 1 and 4 with Me3SnPh were investigated in different solvents, and with 1 two products, trans- [PtPh2(PMe2Ph)(2)] (8) and cis-[PtPh2(PMe2Ph)(2)] (9), were always formed simultaneously. In THF an intermediate, trans- [PtPhMe(PMe2Ph)(2)] (14), was characterized on the path to 9. The kinetics for these reactions were evaluated numerically, and on the basis of rate laws, activation parameters, and reactivity trends a mechanism involving parallel equilibria to 8 and 9 with associative activation in all steps is proposed. In this mechanism the initial attack always takes place trans to the phenyl group, giving 8 and 14, respectively, via an open transition state. In a subsequent reaction, 14 reacts with another molecule of stannane, giving 9 as the final product via a cyclic transition state. Complex 4 gives exclusive formation of cis products: cis-[PtPhMe(PPh3)2] (12) and cis-[PtPh2(PPh3)2] (13). These results are discussed in relation to the reaction mechanism of the transmetalation step in the Stille reaction.},
  author       = {Nilsson, Patrik and Puxty, G and Wendt, Ola},
  issn         = {1520-6041},
  language     = {eng},
  number       = {5},
  pages        = {1285--1292},
  publisher    = {The American Chemical Society (ACS)},
  series       = {Organometallics},
  title        = {Reaction mechanism of transmetalation between tetraorganostannanes and platinum(II) aryltriflate complexes. Mechanistic model for stille couplings},
  url          = {http://dx.doi.org/10.1021/om051021a},
  doi          = {10.1021/om051021a},
  volume       = {25},
  year         = {2006},
}