MOLECULAR CATALYSTS WITH M/NH BIFUNCTIONAL UNITS Nu H Ru Ru X - - PowerPoint PPT Presentation

molecular catalysts with m nh bifunctional units
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MOLECULAR CATALYSTS WITH M/NH BIFUNCTIONAL UNITS Nu H Ru Ru X - - PowerPoint PPT Presentation

MOLECULAR CATALYSTS WITH M/NH BIFUNCTIONAL UNITS Nu H Ru Ru X X Nu N N H H H A A B B amide complex amine complex Nu H Nu : arene, Cp* ligand H : H 2 , (CH 3 ) 2 CHOH, HCOOH, CH 2 (COOR) 2 X : N, P catalyst precursor : Ts R


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SLIDE 1

transfer hydrogenation L = NR2 hydrogenation of ketones L = PR2 hydrogenolysis of epoxides and imides Ru N Ph Ph N Ts Cl H H Rn Ru L N Cl H H N Ru X H

MOLECULAR CATALYSTS WITH M/NH BIFUNCTIONAL UNITS

Nu H : arene, Cp* ligand N Ru X H Nu H X : N, P Nu H : H2, (CH3)2CHOH, HCOOH, CH2(COOR)2 amine complex amide complex Ru Cl Cl Rn N H2 THIS WORK A B A B Nu H catalyst precursor :

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SLIDE 2

REPORTED EXAMPLES OF η1: η6-(AMINOARENE)Ru COMPLEXES

Kurosawa, Inorg. Chim. Acta, 2000 Ru Ph3P Cl N H2 BF4 η6 −arene → η1 : η6 −L−arene

n−2

NH2 1) Birch reduction NH3Cl EtOH reflux 2) HCl n = 2, 3 (CH2)nNH3Cl Ru Cl Cl

2

Ru Cl H2N N SO2 Ph Ph Wills, J. Am. Chem. Soc., 2004 Ru Cl Cl

2

SO2 HN Ph NH3Cl Ph 2-propanol reflux N(C2H5)3 RuCl3 xH2O

n-1 n-1

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SLIDE 3

η1−L → η1 : η6 −L−arene

THIS WORK : INTRAMOLECULAR ARENE DISPLACEMENT REACTION

NH2 CO2Et Ru Cl Cl

2

+ η1 −NH2 complex η1:η6−tethered complex ∆ Ru Cl Cl N H2 Ru Cl Cl NH2 EtOCO

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SLIDE 4

EFFECT OF SUBSTITUENTS FOR η1: η6-(AMINOARENE)Ru COMPLEXES

chlorobenzene 140 °C Ru Cl Cl N H2 yield, %a H >99 m-CH3 p-CH3 R >99 62 80

  • -Si(CH3)3

m-Si(CH3)3 p-Si(CH3)3 88 90 [Ru] = 0.02 M. aIsolated yield. time, h 21 20 2 2 2 18 m,p-(CH3)2 67 17 Ru Cl Cl N H2 EtOCO

R R

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SLIDE 5

EFFECT OF STRUCTURE OF AMINOARENES

H

94

m-Si(CH3)3 p-Si(CH3)3

56 16 2 2

NH2 R O Y R yield, %a R p-Si(CH3)3 p-Si(CH3)3 time, h

2 1

Y CO

69 <1 <1

CH2 NH2

NH2

R1 R2 yield, %a R time, h yield, %a R1 time, h R2 CH3 CO2CH3

18 13

H

98 98

CH3 [Ru] = 0.02 M. aIsolated yield.

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SLIDE 6

Ru Cl N H2 (CH3)3Si +

1H NMR

ESI-TOF TMS η6-C6H4 Si(CH3)3

Ru Cl Cl N H2 (CH3)3Si

CHCl3

SPECTRAL DATA

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SLIDE 7

SYNTHESIS OF CATIONIC ARENE−Ru COMPLEXES

BF4 Ru Ph3P Cl (CH2)2NH3Cl methanol reflux, 20 h 56% yield Ru Cl Cl N H2 Cl methanol rt, 15 h 42% yield this work Ru Ph3P Cl N H2 + + PPh3 + AgBF4 NaOH + NaBF4 Kurosawa, Inorg. Chim. Acta, 2000

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SLIDE 8

Ru−C(1) 2.152(9) Ru−C(2) 2.221(9) Ru−C(3) 2.276(8) Ru−C(4) 2.241(7) Ru−C(5) 2.197(6) Ru−C(6) 2.174(7) Ru−Cl 2.404(2) Ru−N 2.157(7) Ru−P 2.360(2) P−Ru−Cl 87.90(7) P−Ru−N 92.0(2) N−Ru−Cl 84.8(2) Selected bond lengths[Å] and angles[°]

STEREOSELECTIVE FORMATION OF PHOSPHINE COMPLEXES

methanol reflux, 18 h PPh3 AgSbF6 Ru Cl Cl N H2 (CH3)3Si Ru Cl PPh3 N H2 SbF6 (CH3)3Si anti 70% yield phosphine complex with ethylene tether single diastereomer (31P NMR) + R1 (I > 2σ) = 0.094 wR2 = 0.175 P-1 (#2) Z = 2

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SLIDE 9

Ru−C(1) 2.211(4) Ru−C(2) 2.255(4) Ru−C(3) 2.267(5) Ru−C(4) 2.217(5) Ru−C(5) 2.186(6) Ru−C(6) 2.222(6) Ru−Cl 2.3969(13) Ru−N 2.135(4) Ru−P 2.3541(12) Selected bond lengths[Å] and angles[°] P−Ru−Cl 86.13(4) P−Ru−N 90.93(13) N−Ru−Cl 81.05(13) CH2Cl2 rt, 24 h Ru Cl PPh3 N H2 (CH3)3Si SbF6 Ru Cl Cl N H2 (CH3)3Si anti 52% yield single diastereomer (31P NMR) phosphine complex with propylene tether PPh3 AgSbF6 + R1 (I > 2σ) = 0.053 wR2 = 0.143 P-1 (#2) Z = 4

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SLIDE 10

SYNTHESIS OF CATIONIC ISOCYANIDE COMPLEX

Ru Cl Cl N H2 (CH3)3Si Ru Cl CNt-C4H9 N H2 (CH3)3Si + + SbF6 CH2Cl2, rt 2 h, 88% yield IR νN≡C 2201 cm-1 AgSbF6 t-C4H9NC Ru Cl CNt-C4H9 N H2 (CH3)3Si SbF6 IR νN≡C 2197 cm-1 + + CH2Cl2, rt 2 h, 49% yield AgSbF6 t-C4H9NC Ru Cl Cl N H2 (CH3)3Si

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SLIDE 11

Ru−Cl 2.3911(13) Ru−N(1) 2.142(3) Ru−C(13) 1.989(4) N(2)−C(13) 1.142(5) C(13)−Ru−Cl 83.34(13) C(13)−Ru−N 86.91(12) N−Ru−Cl 81.62(11) Selected bond lengths[Å] and angles[°] t-C4H9NC AgSbF6 CH2Cl2 rt, 1 h Ru t-C4H9NC Cl N H2 (CH3)3Si SbF6 Ru Cl Cl N H2 (CH3)3Si Ru Cl CNt-C4H9 N H2 (CH3)3Si SbF6 syn 16% yield anti isocyanide complex with propylene tether + IR νN≡C 2193 cm-1 R1 (I > 2σ) = 0.044 wR2 = 0.090 P-1 (#2) Z = 2

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SLIDE 12

Si(CH3)3 Ru Cl Cl

2

R1 = n-C6H13 7 9

aDetermined by 1H NMR.

yield, %a

EFFECT OF AMINO-TETHER IN HYDROGEN TRANSFER

O Ru cat t-C4H9OK OH H 2-propanol 30 °C, 1 h ketone:Ru:t-C4H9OK = 10:1:1, [ketone] = 0.1 M Ru Cl Cl N H2 (CH3)3Si Ru Cl Cl N H2 (CH3)3Si 28 >99 yield, %a Ru Cl Cl N H2 (CH3)3Si <1 (without base) Ru Cl Cl NR1 H2 (CH3)3Si

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SLIDE 13

aDetermined by 1H NMR.

HYDROGEN TRANSFER USING CATIONIC COMPLEXES

O Ru cat t-C4H9OK OH H 2-propanol 30 °C, 1 h ketone:Ru:t-C4H9OK = 10:1:1, [ketone] = 0.1 M Ru Cl PPh3 N H2 (CH3)3Si >99 10 yield, %a <1 Ru Cl Cl N H2 (CH3)3Si SbF6 Ru Cl CNt-C4H9 N H2 (CH3)3Si SbF6

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SLIDE 14

PROPOSED MECHANISM

Ru Cl Cl N H2 base Ru Cl N H Ru Cl L N H2 base Ru Cl N H SbF6 L Ru Cl H N H2 R OH R O H + + – HSbF6 – HCl – L L

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SLIDE 15

SUMMARY

Novel synthetic method for various η1:η6-(aminoarene)Ru complexes Stereocontrol based on a planar chirality η1 −NH2 complex η1:η6−tethered complex ∆ Ru Cl Cl N H2 Potent hydrogen transfer ability Ru Cl Cl NH2 EtOCO