A Versatile and High-Yield Route to Active and Well-Defined Catalysts [Ru(bisphosphane)(H)(solvent)3](BF4)

Wiles, Jason A.; Bergens, Steven H.; Vanhessche, Koenraad P. M.; Dobbs, Daniel A.; Rautenstrauch, Valentin

doi:10.1002/1521-3773(20010302)40:5<914::aid-anie914>3.3.co;2-r

Cited by 9 publications

(14 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, the in situ generated RuBr 2 [diphosphine] catalysts were prepared according to our convenient procedure, by mixing Ru(cod)(η 3 -methylallyl) 2 with the required diphosphines in the presence of methanolic hydrobromic acid, which gave the 3-aminochroman derivative 2a in moderate to good yields and selectivities ranging from 61 to 78% ee (Table , entries 1–4, 44–82% yields). Similar catalytic activity was achieved with the cationic monohydride ruthenium complex [Ru(H)(η 6 -cot)Diphosphine] + BF 4 – , which was previously successfully used for the industrial synthesis of (+)- cis -methyldihydrojasmonate (entries 5–8, 38–76% yields, and 72–80% ee). When the reaction was carried out with the preformed dimeric [{RuCl(( S )-Diphosphine)} 2 (μ-Cl) 3 ] − [NH 2 Me 2 ] + complexes (entries 9–12) or the cationic [RuCl{( p -cym)( S )-Diphosphine}] + Cl – catalysts (entries 13–16), a significant increase in terms of both conversions and yields was observed.…”

mentioning

confidence: 58%

Efficient Enantioselective Synthesis of 3-Aminochroman Derivatives Through Ruthenium-Synphos Catalyzed Asymmetric Hydrogenation

Ayad

Ratovelomanana‐Vidal

2011

Org. Lett.

View full text Add to dashboard Cite

A highly enantioselective asymmetric hydrogenation of various trisubstituted enamides derived from chroman-3-ones promoted by cationic Ru-Synphos catalysts is reported. This atom-economical and clean method provides an efficient route to optically active 3-aminochroman derivatives, which are important pharmacophores found in numerous drug candidates, in high chemical yields and enantiomeric excesses up to 96%.

show abstract

mentioning

confidence: 58%

Efficient Enantioselective Synthesis of 3-Aminochroman Derivatives Through Ruthenium-Synphos Catalyzed Asymmetric Hydrogenation

Ayad

Ratovelomanana‐Vidal

2011

Org. Lett.

View full text Add to dashboard Cite

show abstract

“…Two singlets at about 70 and 65 ppm were found in the 31 P{ 1 H} NMR spectra of 6 − 10 , indicating the presence of planar chirality in all those ruthenium hydride complexes. Their solid-state IR spectra all displayed a characteristic terminal B-H absorption at around 2550 cm -1 and the frequency of a Ru-H stretch at around 1970 cm -1 . The composition of 6 − 10 was confirmed by elemental analyses.…”

Section: Resultsmentioning

confidence: 91%

Reaction Scope and Mechanism of Sterically Induced Ruthenium-Mediated Intramolecular Coupling ofo-Carboranyl with Cyclopentadienyl. Synthesis and Structure of Ruthenium Complexes Incorporating Doubly Linked Cyclopentadienyl−Carboranyl Ligands

2006

View full text Add to dashboard Cite

Reactions of [Me(R1)A(C5H3R2)(C2B10H10)]Li2 (A = C, Si; R1 = H, Me; R2 = H, Me) with 1 equiv of RuCl2(PPh3)3 in THF afforded the corresponding doubly linked cyclopentadienyl−carboranyl ruthenium(II) hydride complexes [η 5-Me2C(C5H3)(C2B10H10)]RuH(PPh3)2 (6), [η 5-MeHC(C5H3)(C2B10H10)]RuH(PPh3)2 (7), [η 5-Me2C(5-Me-C5H2)(C2B10H10)]RuH(PPh3)2 (8), [η 5-Me2C(3/4-Me-C5H2)(C2B10H10)]RuH(PPh3)2 (9a/9b), and [η 5-Me2Si(C5H3)(C2B10H10)]RuH(PPh3)2 (10) in 72−85% isolated yields. On the other hand, interaction of [Me2C(C5H4)(C2B10H10)]Li2 with 1 equiv of RuCl2[PPh2(OEt)]3 produced only [η 5:σ-Me2C(C5H4)(C2B10H10)]Ru[PPh2(OEt)]2 (14). An equimolar reaction of [Me2C(C5H4)(C2B10H10)]Li2 with RuCl2(PPh3)3 in the presence of dppe (dppe = 1,2-bis(diphenylphosphino)ethane) generated [η 5:σ-Me2C(C5H4)(C2B10H10)]Ru(dppe) (15). No ruthenium hydride complexes were detected in the latter two cases. Treatment of [η 5-Me2C(C5H3)(C2B10H10)]RuH(PPh3)2 (6) with excess HBF4·OEt2 in toluene gave the neutral ligand Me2C(C5H4)(C2B10H10) (12). This work showed that such intramolecular coupling reactions were driven by steric factors. A possible reaction mechanism was proposed to account for these ruthenium-mediated coupling reactions. All new complexes were fully characterized by multinuclear NMR techniques and elemental analyses. Molecular structures of 6, 7, and 8 were further confirmed by single-crystal X-ray analyses.

show abstract

“…The catalyst precursor 19 is prepared by treatment of [Ru(COD)(Z 3 -methylallyl) 2 ] with Me-DuPhos (13a) and HBF 4 in CH 2 Cl 2 . 60,62 This particular precursor was developed to circumvent the base treatment normally used to activate ruthenium catalysts, as a residual base would lead to the rapid epimerisation of the product 18. Other complexes based on JosiPhos (7) were screened, as these can also perform the reduction but Me-DuPhos provided the best performance.…”

Section: Methyl (+)-Cis-dihydrojasmonatementioning

confidence: 99%

“…Zhang and coworkers have solved this problem by the use of a rhodium catalyst with the ligand Duanphos (61). 92 A similar approach has been used to the related drug, Fluoxetine (62), also from Lilly. 93 The utility of the system was also exploited in a synthesis of a DPE-IV inhibitor (63) by Merck (Scheme 17).…”

Section: Other Examplesmentioning

confidence: 99%

Asymmetric homogeneous hydrogenations at scale

Ager¹,

2012

View full text Add to dashboard Cite

Asymmetric hydrogenations are increasingly being used to introduce stereogenic centres into products used in the life sciences industries. There are a number of potential pitfalls when moving from a laboratory reaction to a manufacturing process, not least of which is safety. Time-to-market pressure leads to short development times, which in the past could be a large barrier for the implementation of catalytic steps; now there are new ways to minimise this problem. The potential problems associated with impurities and other methods that can shut down the hydrogenation reactions are highlighted in this critical review (353 references).

show abstract

A Versatile and High-Yield Route to Active and Well-Defined Catalysts [Ru(bisphosphane)(H)(solvent)3](BF4)

Cited by 9 publications

References 0 publications

Efficient Enantioselective Synthesis of 3-Aminochroman Derivatives Through Ruthenium-Synphos Catalyzed Asymmetric Hydrogenation

Efficient Enantioselective Synthesis of 3-Aminochroman Derivatives Through Ruthenium-Synphos Catalyzed Asymmetric Hydrogenation

Reaction Scope and Mechanism of Sterically Induced Ruthenium-Mediated Intramolecular Coupling ofo-Carboranyl with Cyclopentadienyl. Synthesis and Structure of Ruthenium Complexes Incorporating Doubly Linked Cyclopentadienyl−Carboranyl Ligands

Asymmetric homogeneous hydrogenations at scale

Contact Info

Product

Resources

About