Catalysis of Kumada–Tamao–Corriu coupling by a (POCOP)Rh pincer complex

Timpa, Samuel D.; Fafard, Claudia M.; Herbert, David E.; Ozerov, Oleg V.

doi:10.1039/c1dt10161g

Cited by 37 publications

(43 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In particular, we were able to establish that a T-shaped Rh I center supported by an anionic pincer ligand possesses a rather striking similarity in its reactivity to the LPd 0 fragment. [13][14][15][16][17][18] This approach with Rh proved especially fruitful in catalytic C-S coupling. 19 Catalytic C-S coupling with Pd has received a considerable amount of attention.…”

Section: Introductionmentioning

confidence: 99%

Concerted aryl-sulfur reductive elimination from PNP pincer-supported Co(iii) and subsequent Co(i)/Co(iii) comproportionation

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Concerted aryl-sulfur reductive elimination from PNP pincer-supported Co(iii) and subsequent Co(i)/Co(iii) comproportionation

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Driess and Hartwig tested iridium complexes supported by the sterically bulky SiCSi (silylene-arylsilylene) and POCOP tBu pincers, finding that they gave low TON (<20) under similar conditions. 33,34 Reacting [(COD)IrCl] 2 with pyridine or DMAP, 35 followed by the addition of 1a and p-Me POCOP iPr (1b, Figure 1), gave adducts 2a-DMAP and 2b (Scheme 2a). 22 It was remarked that the sterically imposing pincers used in their study may have been detrimental to catalysis.…”

Section: Introductionmentioning

confidence: 99%

High-Turnover Aromatic C–H Borylation Catalyzed by POCOP-Type Pincer Complexes of Iridium

et al. 2016

Self Cite

View full text Add to dashboard Cite

The catalytic C-H borylation of arenes with HBpin (pin = pinacolate) using POCOP-type pincer complexes of Ir has been demonstrated, with turnover numbers exceeding 10 000 in some cases. The selectivity of C-H activation was based on steric preferences and largely mirrored that found in other Ir borylation catalysts. Catalysis in the (POCOP)Ir system depends on the presence of stoichiometric quantities of sacrificial olefin, which is hydrogenated to consume the H2 equivalents generated in the borylation of C-H bonds with HBpin. Smaller olefins such as ethylene or 1-hexene were more advantageous to catalysis than sterically encumbered tert-butylethylene (TBE). Olefin hydroboration is a competing side reaction. The synthesis and isolation of multiple complexes potentially relevant to catalysis permitted examination of several key elementary reactions. These experiments indicate that the C-H activation step in catalysis ostensibly involves oxidative addition of an aromatic C-H bond to the three-coordinate (POCOP)Ir species. The olefin is mechanistically critical to gain access to this 14-electron, monovalent Ir intermediate. C-H activation at Ir(I) here is in contrast to the olefin-free catalysis with state-of-the-art Ir complexes supported by neutral bidentate ligands, where the C-H activating step is understood to involve trivalent Ir-boryl intermediates.

show abstract

“…26 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Scheme 4. Synthesis of Rh pincer complexes.…”

unclassified

A Series of Pincer-Ligated Rhodium Complexes as Catalysts for the Dimerization of Terminal Alkynes

Pell

Ozerov

2014

ACS Catal.

Self Cite

View full text Add to dashboard Cite

A series of pincer complexes of Rh has been prepared and tested as catalysts for the dimerization of terminal alkynes. The pincers included aryl/bis(phosphinite) POCOP, aryl/bis(phosphine) PCP, and diarylamido/bis(phosphine) PNP ligands. Rh I complexes of the general form (pincer)Rh(S i Pr 2 ) or (pincer)Rh(H 2 ) were used as catalysts. In addition, the apparent donating ability of the pincer ligands was gauged through the carbonyl stretching frequencies in (pincer)Rh(CO) complexes by IR spectroscopy. All surveyed Rh complexes acted as catalysts for dimerization of 4-ethynyltoluene, 1-hexyne, or trimethysilylacetylene. The products were a mixture of E-and gem-enyne isomers, with small amounts of oligomers in some cases. The Z-enyne isomers were not observed except in two reactions. None of the catalysts showed useful selectivity for either the E-or the gem-enyne product. However, the POCOP-based catalysts bearing P i Pr 2 donor arms performed faster and possessed apparently greater longevity (up to 20,000 TON) than the previously reported pincer Rh catalysts.

show abstract

Catalysis of Kumada–Tamao–Corriu coupling by a (POCOP)Rh pincer complex

Cited by 37 publications

References 37 publications

Concerted aryl-sulfur reductive elimination from PNP pincer-supported Co(iii) and subsequent Co(i)/Co(iii) comproportionation

Concerted aryl-sulfur reductive elimination from PNP pincer-supported Co(iii) and subsequent Co(i)/Co(iii) comproportionation

High-Turnover Aromatic C–H Borylation Catalyzed by POCOP-Type Pincer Complexes of Iridium

A Series of Pincer-Ligated Rhodium Complexes as Catalysts for the Dimerization of Terminal Alkynes

Contact Info

Product

Resources

About