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8 9 F 1 1 2 C p R u ( P N ) * ( )

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SLIDE 1

非対称ジオール類のラクトン化反応における位置選択性と カチオン性C p

*

R u ( P N ) 錯体の構造との相関

日本化学会第8 9 春季年会 １F 1 1 2

( 東工大院理工) 伊藤 正人○椎橋 彬・碇屋 隆雄

slide-2
SLIDE 2

Cp*Ru(PN) CATALYSTS WITH A BIFUNCTION BASED ON METAL/NH BOND

  • Org. Biomol. Chem. 2006, 4, 393.

[Ru] [Ru]-H2 Ru N Ar2P R H H OR2 R1 Ru N Ar2P R H H O R2 R1 16e amide complex 18e amine hydride complex Lactonization of α,ω-diols OH OH R R H OH O R R O HO H R R O O R R [Ru] [Ru]-H2 [Ru] [Ru]-H2 O OH H O OH H

  • Org. Lett. 2007, 9, 1821.

Ru N H O H R R' Possible transition state

slide-3
SLIDE 3

OH OH CpRu(PN) KOt-Bu acetone +

4 1 2 4 1 2

O O R R O O

4 1 2

R A B

THIS WORK: REGIOSELECTIVE LACTONIZATION OF 2-BENZYL-1,4-BUTANEDIOL

Hinokinin Isodeoxypodophyllotoxyn Podophizol acetate Isostegane Ru NHR Cl R2P R R R R CpRu(PN) O O O O O O O O O O O OCH3 OCH3 CH3O OCH3 OCH3 CH3O O OCH3 CH3O CH3O O O O O AcO O O O O

4 1 2

R

slide-4
SLIDE 4

NH2 R2P R = o-Tol Cy t-Bu NH2 Ph2P R R = Ph Bn NH2 Ph2P 90:10

  • -Tol

Cy t-Bu 81:19 76:24 88:12 96:4 94:6 (48 h) Ph2P NH2 Ph2P NH2 N Ph2P 80:20 92:8 81:19 Me Bn 82:18 83:17 H NHR Ph2P R = H

STRUCTURAL EFFECT OF PN LIGAND ON REGIOSELECTIVITY

Ru NHR Cl R2P 77:23 [Ru] KOt-Bu acetone 30 °C, 1 h A B + diol:[Ru]:KOt-Bu = 100:1:1 >99% yield [diol] = 0.5 M OH OH O O O O [Ru]

1 4 1 4 1 4

slide-5
SLIDE 5

NH2 R2P R = o-Tol Cy t-Bu NH2 Ph2P R R = Ph Bn NH2 Ph2P 90:10

  • -Tol

Cy t-Bu 81:19 76:24 88:12 96:4 94:6 (48 h) Ph2P NH2 Ph2P NH2 N Ph2P 80:20 92:8 81:19 Me Bn 82:18 83:17 H NHR Ph2P R = H

STRUCTURAL EFFECT OF PN LIGAND ON REGIOSELECTIVITY

Ru NHR Cl R2P 77:23 [Ru] KOt-Bu acetone 30 °C, 1 h A B + diol:[Ru]:KOt-Bu = 100:1:1 >99% yield [diol] = 0.5 M OH OH O O O O [Ru]

1 4 1 4 1 4

slide-6
SLIDE 6

NH2 R2P R = o-Tol Cy t-Bu NH2 Ph2P R R = Ph Bn NH2 Ph2P 90:10

  • -Tol

Cy t-Bu 81:19 76:24 88:12 96:4 94:6 (48 h) Ph2P NH2 Ph2P NH2 N Ph2P 80:20 92:8 81:19 Me Bn 82:18 83:17 H NHR Ph2P R = H

STRUCTURAL EFFECT OF PN LIGAND ON REGIOSELECTIVITY

Ru NHR Cl R2P 77:23 [Ru] KOt-Bu acetone 30 °C, 1 h A B + diol:[Ru]:KOt-Bu = 100:1:1 >99% yield [diol] = 0.5 M OH OH O O O O [Ru]

1 4 1 4 1 4

slide-7
SLIDE 7

NH2 R2P R = o-Tol Cy t-Bu NH2 Ph2P R R = Ph Bn NH2 Ph2P 90:10

  • -Tol

Cy t-Bu 81:19 76:24 88:12 96:4 94:6 (48 h) Ph2P NH2 Ph2P NH2 N Ph2P 80:20 92:8 81:19 Me Bn 82:18 83:17 H NHR Ph2P R = H

STRUCTURAL EFFECT OF PN LIGAND ON REGIOSELECTIVITY

Ru NHR Cl R2P 77:23 [Ru] KOt-Bu acetone 30 °C, 1 h A B + diol:[Ru]:KOt-Bu = 100:1:1 >99% yield [diol] = 0.5 M OH OH O O O O [Ru]

1 4 1 4 1 4

slide-8
SLIDE 8

Kuhn, L. P.; Schleyer, P. R.; Baitinger, Jr., W. F.; Eberson, L. J. Am. Chem. Soc. 1964, 86, 650.

H H Ph Ru N P R H H O H O H H

C1 C2

STERIC HINDERANCE BETWEEN SUBSTITUENT ON PHOSPHINE AND SUBSTRATE

■ effect of the substituent on phosphine ■ Possible transition state Dehydrogenation of alcohol at 1 position Hindered! Regioselectivity: High Ph2P NH2 (o-Tol)2P NH2 (t-Bu)2P NH2 77:23 88:12 94:6

1 4

Cy2P NH2 96:4

slide-9
SLIDE 9

THE REACTIONS OF Cp*Ru(PN) AND 2,6-XyNC

PN Ligand Ph2P NH2 Ph2P NH2 yield, % 92 precursor PN Ligand yield, % precursor B B (o-Tol)2P NH2 A (t-Bu)2P NH2 A 65 72 46 2,6-XyNC CH2Cl2 rt X X = Cl or OTf Ru NH2 Cl R2P

  • r

Ru NH2 CNXy R2P A B Ru NH2 NCMe R2P OTf A 66 2,6-XyNC Ph2P NH2 CN (77:23) (88:12) (94:6) (81:19) (92:8)

slide-10
SLIDE 10

Ru P N1 C１ C2

CRYSTAL STRUCTURE OF Cp*Ru(XyNC)(PN): ETHYLENE CHAIN

C2/c (#15) R1 = 0.056 wR2 = 0.166 P21/n (#14) R1 = 0.059 wR2 = 0.153 ∠ C1-P-C2 = 101.6(2) ° P21/c (#14) R1 = 0.059 wR2 = 0.197 ∠ C1-P-C2 = 105.51 (18) ° ∠ C1-P-C2 = 109.0(2) ° ∠ Ct-Ru-P-C2 = 97.28 ° Regioselectivity ∠ Ct-Ru-P-C1 = –28.70 ° ∠ Ct-Ru-P-C2 = 105.87 ° ∠ Ct-Ru-P-C1 = –25.47 ° ∠ Ct-Ru-P-C2 = 107.37 ° ∠ Ct-Ru-P-C1 = –27.33 ° 77:23 88:12 94:6 Ph

  • -Tol

t-Bu

Ru P N1 C１ C2 Ru P N1 C１ C2

Ph2P NH2 (o-tol)2P NH2 (t-Bu)2P NH2 dihedral angle : The regioselectivity is better as ∠ Ct-Ru-P-C2 is larger. The regioselectivity is better as ∠ C1-P-C2 is larger.

P (C2)Ar (C1)Ar Ru XyNC NH2 C1-P-C2

θ Cp* Ru XyNC NH2 C2 P C1

slide-11
SLIDE 11

N H O H Ru P H O H H H

C1 C2

R Top view Large steric hinderance between ligand and substrate High regioselectivity Large dihedral angle H H Ph Ru N P R H H O H O H H

C1 C2

EFFECT OF THE ANGLES

■ Effect of the angle formed by C1-P-C2 High regioselectivity

1 4

■ Effect of the dihedral angle Large steric hinderance between alkyl group on phosphine and substrate

slide-12
SLIDE 12

C2/c (#15) R1 = 0.056 wR2 = 0.166 77:23 P21/c (#14) R1 = 0.065 wR2 = 0.229

CRYSTAL STRUCTURE OF Cp*Ru(XyNC)(PN): PROPYLENE CHANE

_ P1 (#2) R1 = 0.049 wR2 = 0.132 Regioselectivity 82:18 92:8

Ru P N1 N2 C１ C2

Ru P N1 C１ C2 C3 Ru N1 C１ C2 C3 P

∠ C1-P-C2 = 101.6(2) ° ∠ C1-P-C2 = 103.2(2) ° ∠ C1-P-C2 = 104.1(3) ° ∠ Ct-Ru-P-C2 = 97.28 ° ∠ Ct-Ru-P-C1 = –28.70 ° ∠ Ct-Ru-P-C2 = 83.85 ° ∠ Ct-Ru-P-C1 = –38.67 ° ∠ Ct-Ru-P-C2 = 98.38 ° ∠ Ct-Ru-P-C1 = –24.34 ° Ph2P NH2 Ph2P NH2 Ph2P NH2

slide-13
SLIDE 13

SUMMARY

OH OH Cp*RuCl(PN) KOt-Bu acetone 30 °C O O O O + diol:Ru:KOt-Bu = 100:1:1 [diol] = 0.5 M NH2 R2P NH2 Ph2P Ph2P NH2 >99% 90:10 92:8 R = o-tol Cy 88:12 96:4 ■ The structural bulkiness around phosphine is important for the regioselectivity. ■ Regioselective lactonization of unsymmetrical diols A B Ru NHR Cl R2P R R R R CpRu(PN)