CH BOND ACTIVATION WITH METAL AMIDE COMPLEXES Ts Ts R R N - - PowerPoint PPT Presentation

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c h bond activation with metal amide complexes
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CH BOND ACTIVATION WITH METAL AMIDE COMPLEXES Ts Ts R R N - - PowerPoint PPT Presentation

Jun 16, 2023 227 likes •324 views

CH BOND ACTIVATION WITH METAL AMIDE COMPLEXES Ts Ts R R N N L + CH 3 NO 2 M L M CH 2 N N R R H H 2 NO 2 ML: Ruarene, RhCp*, IrCp* NTs C 6 H 5 NTs Ts = p -CH 3 C 6 H 4 SO 2 NH 2 C 6 H 5 NH 2 ( S,S )-Tsdpen (

slide-1
SLIDE 1

N M N Ts R R H

C–H BOND ACTIVATION WITH METAL AMIDE COMPLEXES

+ CH3NO2 N M N Ts R R H2 L CH2 M–L: Ru–arene, Rh–Cp*, Ir–Cp* Ts = p-CH3C6H4SO2 (S,S)-Tsdpen (S,S)-Tscydn L NO2 NH2 NTs C6H5 C6H5 NH2 NTs

slide-2
SLIDE 2

R H O CH3NO2

NITROALDOL REACTION WITH CHIRAL METAL COMPLEXES

N N Ts R R CH2 NO2 M N N Ts R R H M N N C6H5 C6H5 NO2 M H O H R electrophilic activation nucleophilic attack Ts H HO H NO2 R H H

δ+ δ− δ+ δ−

M: Ru, Rh, Ir

slide-3
SLIDE 3

CH3NO2 + 2-methyl-2-butanol 30 ˚C, 24 h H O OH NO2

S

chiral cat 37 40 ee, % 29 25 chiral cat

NITROALDOL REACTION WITH CHIRAL METAL COMPLEXES

Ru[(S,S)-Tsdpen](p-cymene) Cp*Rh(CH2NO2)[(S,S)-Tscydn] Cp*Ir(CH2NO2)[(S,S)-Tscydn] yield, % Conditions: cat:aldehyde:CH3NO2 = 1:50,100, [aldehyde] = 0.2 M

slide-4
SLIDE 4

CH3NO2 + chiral Ru cat 24 h, 30 ˚C C6H5 H O C6H5 OH NO2

S

conv, % solvent 88 40 yield, % 37 ee, % 2-methyl-2-butanol 80 30 30 2-propanol 34 30 10 toluene 6 39 4 THF

SOLVENT EFFECT FOR ASYMMETRIC NITROALDOL REACTION

Conditions: Ru:aldehyde:CH3NO2 = 1:50:100, [aldehyde] = 0.2 M methanol 100 13 17 solvent chiral Ru cat: Ru[(S,S)-Tsdpen](p-cymene)

slide-5
SLIDE 5

CH3NO2, equiv temp, ˚C 2 30 88 40 50 33 conv, % 45 2 ee, %

EFFECTS OF THE AMOUNT OF CH3NO2

5 10 36 63 5 30 10 30 26 7 81 100 yield, % 32 37 56 65 83 C6H5 OH NO2

S

Conditions: Ru:aldehyde = 1:50, [aldehyde] = 0.2 M in 2-methyl-2-butanol chiral Ru cat: Ru[(S,S)-Tsdpen](p-cymene)

slide-6
SLIDE 6

10 20 80 100 conv, % ee, % 60 40 20 30 80 100 60 40 20 time, h conv, % ee, % chiral Ru cat: Ru[(S,S)-Tsdpen](p-cymene)

TIME DEPENDENCE OF EE VALUES

Condition: Ru:aldehyde:CH3NO2 =1:50:100, [aldehyde] = 0.2 M in 2-methyl-2-butanol, 30 ˚C

slide-7
SLIDE 7

chiral Ru cat 24 h R OH NO2

S

R H O 2-methyl-2-butanol

ASYMMETRIC NITROALDOL REACTION OF ALDEHYDES

R C6H5(CH2)2 C6H5 C6H11 yield, % ee, % 56 36 20 20 18 75 S/C = 50 temp, °C CH3NO2 + CH3NO2, equiv 10 30 30 5 2 2 Conditions: [aldehyde] = 0.2 M chiral Ru cat: Ru[(S,S)-Tsdpen](p-cymene)

slide-8
SLIDE 8

REACTION OF PHENYLPROPANAL WITH NITROETHANE

+ CH3CH2NO2 chiral Ru cat NO2 OH NO2 OH Ru:aldehyde:nitroethane = 1:50:100, [aldehyde] = 0.2 M + C6H5 H O C6H5 C6H5 30 ˚C, 24 h 2-methyl-2-butanol 48% yield syn anti 1:1

S S

51% ee

S R

33% ee chiral Ru cat: Ru[(S,S)-Tsdpen](p-cymene)

slide-9
SLIDE 9

chiral Ru cat R OH NO2 R H O 2-methyl-2-butanol

CONCLUSION

R'CH2NO2 + 36–75% ee 18–56% yield S/C = 50 chiral Ru cat: Ru[(S,S)-Tsdpen](p-cymene) 10–30 °C, 24 h R'CH2NO2: CH3NO2, CH3CH2NO2 R' * *

ACKNOWLEDGEMENTS

  • Prof. M. Shibasaki (Tokyo Univ. )

R: C6H5(CH2)2, C6H5, C6H11