Ruthenium- and Platinum-Catalyzed Sequential Reactions:Selective Synthesis of Fused Polycyclic Compounds from

Propargylic Alcohols and Alkenes

Yoshiaki Nishibayashi,* Masato Yoshikawa, YouichiInada, Masanobu Hidai, and Sakae Uemura*

J. Am. Chem. Soc., ASAP Article 10.1021/ja045532k S0002-7863(04)05532-5

Web Release Date: November 18, 2004

and

PtCl2

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Introduction

• Bimetallic system, different catalytic cycle, same medium.• No successive addition of reagents. No change in temperature or

atmosphere on the way.

[Ru]PtCl2

Ruth Nunes @ Wipf Group 2 12/2/04

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•Bimetallic system, different catalytic cycle, same medium. Catalysts activating different functional groups.

Pd0-CuI synthesis of indoles from isocyanates:

Asymmetric Tsuji-Trost:

Yamamoto et al, ACIEE, 2002, 41, 3230.

R1

N C OOCO2R2

NR1

CO2R2

1 mol% [Pd(PPh3)4]

4 mol% CuClTHF

OCO2R

R1

CNCOR2

H

+PdL*

CNR1

R2 O-

RhL*

CN

R1

COR2

cat. Pd0

cat. RhI

Ito et al, JACS, 1996, 118, 3309.

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•Bimetallic system, different catalytic cycle, same medium.

Catalysts activating intermediates sequentially.

Pd0-RhI synthesis of bicyclopentenones:

Jeong et al, JACS, 2000, 122, 10220

BSA

Not reactive

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Triple Tandem catalysts mix synthesis of polyethylenes:

Bazan et al, JACS, 2002, 124, 15280.

[Ti]

[Ni]-2[Ni]-3

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Results and Discussion

Best conditions: ClCH2CH2Cl, NH4BF4 (10 mol%), 60 °C, 24h.

PtCl4, PdCl2, AuCl3 and [Rh(OAc)2]2 not effective.

Selenolate-bridged diruthenium complex afforded moderate yield, but theTellurolate one provided low yield.

Uemura, Nishibayashi et al, JACS, 2004, ASAP.

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Scope and limitation:

Uemura, Nishibayashi et al, JACS, 2004, ASAP.

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Scope and limitation:

Uemura, Nishibayashi et al, JACS, 2004, ASAP.

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[Ru]/PtCl2 system and the synthesis of furans and pyrrols:

Hidai, Uemura et al, ACIEE, 2003, 42, 2681.

ROH

R1 R2

O O R1

R R3

R1, R2 = alky cyclic R3 = R2 - 1CH2

52 - 83%R = aromatic

[Ru], 10 mol%

PtCl2 20 mol%52 - 83%

[Ru], 10 mol%

PtCl2 20 mol%44 - 58%

PhOH O

ArNH2

N

Ph

Ar

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So, the mechanism

Hidai et al, JACS, 2000, 122,11019.Hidai, Uemura et al, JACS, 2003, 125,6060.

Hidai, Uemura et al, JACS, 2002, 124,15172.

ROH

SMeMeS

Cp*Cp*

α

βγ RH

Cl

allenylidene complex

BF4

[Ru] R'OH

R'SHR'NH2

HPOPh2R'CONHMe

alkenes

RNu

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So, the mechanism.

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Conclusion

Fused polycyclic compounds made through a bimetallic catalytic system in a sequential [Ru]I promoted propargylic alcohol substitution, followed by a PtCl2 cycloisomerisation.Catalysts operating in the same conditions. Simple experiment set up.Moderate to excellent yields, good diastereoselectivity.Broadening of the scope of the sequence is necessary.Application in natural products synthesis was not mentioned.

Ruth Nunes @ Wipf Group 12 12/2/04