EARLY EXAMPLES FOR RuCATALYZED LACTONIZATION O OH Ru cat. - - PowerPoint PPT Presentation

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EARLY EXAMPLES FOR RuCATALYZED LACTONIZATION O OH Ru cat. acceptor + O OH n n n = 1, 2 condition; RuH 2 (PPh 3 ) 4 , acetone (03 equiv), toluene, 180 C Murahashi, Ito, Naota, Maeda, Tetrahedron Lett. , 1981 , 22 , 5327. Ru 3

SLIDE 1

EARLY EXAMPLES FOR Ru–CATALYZED LACTONIZATION

OH OH n Ru cat. O O n + acceptor condition; RuH2(PPh3)4, acetone (0–3 equiv), toluene, 180 °C Murahashi, Ito, Naota, Maeda, Tetrahedron Lett., 1981, 22, 5327. Ru3(CO)12, C6H5C≡CC6H5 (2 equiv), diglyme, 145 °C Shovo, Blum, Reshef, Menzin, J. Organomet, Chem., 1982, 226, C21. Ru2Cl4((-)diop)3 (2.0 mol%) PhCH=CHCOCH3 (2 equiv) toluene, reflux n = 1, 2 OH OH n n O O Ishii, Osakada, Ikariya, Saburi, Yoshikawa, Chem. Lett., 1982, 1179. up to 12% ee

SLIDE 2

LACTONIZATION OF α,ω-DIOLS

N Ru P H H H R C R' O Ar Ar N Ru P H H H R C R' O Ar Ar R R OH OH Cp*RuCl(cod) (C6H5)2P(CH2)2NH2, KOt-Bu acetone, 30 °C, 1 h R R O O >99% yield a possible transformation 伊藤正人, 大迫章英, 碇屋隆雄, 第79 春季年会, 1H3 2 6 . diol:Ru:ligand:KOt-Bu = 100:1:1:1, [diol] = 0.5 M

SLIDE 3

O R1N O R2 HP(C6H5)2 CF3SO3H i-Pr Ph Bn i-Bu R2 R1 H H H H

S

t-Bu H [CH(CH3)2] [CH2CH2(CH3)2] [C(CH3)3] [C6H5] [CH2C6H5] R1HN P(C6H5)2 R2 yield, %a 89 70 70

a Isolated yield

85

(CH2)3-

55 SYNTHESIS OF P–N LIGANDS

66 + toluene reflux, 24 h

xazolidinone:HP(C6H5)2:CF3SO3H = 1:2:3

S

SLIDE 4

OH OH O

ENANTIOSELECTIVE LACTONIZATION

Cp*RuCl(cod) chiral ligand KOt-Bu acetone 30 °C, 1 h R1HN P(C6H5)2 R2 H, Bn R1, R2 H, i-Pr H, i-Bu H, t-Bu H, Ph

(CH2)3-

yield, % ee, %a diol:Ru:chiral ligand:KOt-Bu = 100:100:1:1:1 >99 >99 >99 >99 >99 >99 44 42 39 50 46 10 O

chiral ligand

S R

SLIDE 5

H2N P(C6H5)2 Bn R R OH OH R R O O

ENANTIOSELECTIVE LACTONIZATION

CpRuCl(cod) chiral ligand KOt-Bu 30 °C, 1 h 99% yield 2% ee 99% yield 13% ee (1S,5R) >99% yield 34% ee (1R,6S) >99% yield 31% ee (3aR,7aS) >99% yield 43% ee (2R,3S) >99% yield 50% ee (2R,3S) >99% yield 16% ee (2S,3R) >99% yield 11% ee (2S,3R) * diol:Ru:chiral ligand:KOt-Bu = 100:100:1:1:1 O O O O O O O O O O O O O O O

chiral ligand

O

R S R S R S R S S R S R R S

SLIDE 6

OH OH O O O

CONTROL OF CONVERSION

Cp*RuCl(cod) (C6H5)2P(CH2)2NH2 KOt-Bu toluene 30 °C, 1 h + diol:Ru:ligand:KOt-Bu = 100:1:1:1 diol:acetone 1 : 2 1 : 1 conv, % >99 50

SLIDE 7

H, Bn R1HN P(C6H5)2 R2

KINETIC RESOLUTION OF rac-1,4-BUTANDIOL

R1, R2 H, i-Pr H, i-Bu H, t-Bu H, Ph

(CH2)3-

ee, %a (reactant) diol:acetone:Ru:chiral ligand:KOt-Bu = 100:100:1:1:1 79 50

chiral ligand

54 63 70 23 Ar Ar OH OH OH OH Ar Ar OH OH Ar Ar O Ar Ar O + Cp*RuCl(cod) chiral ligand KOt-Bu acetone toluene 30 °C, 1 h + 50:50 Ar = C6H5

SLIDE 8

SUMMARY

R R OH OH Ar Ar OH OH OH OH Ar Ar R R O O OH OH Ar Ar H2N P(C6H5)2 Bn O Ar Ar O CpRuCl(cod) chiral ligand KOt-C4H9 acetone 30 °C, 1 h >99% yield * up to 50% ee Enantioselective lactonization of meso-1,4-butandiols Kinetic resolution of racemic 1,4-butandiol up to 79% ee + Cp*RuCl(cod) chiral ligand KOt-Bu acetone toluene 30 °C, 1 h