Reactions Catalyzed by Rhenium Carbonyl Complexes

杜宇鎏 2012.5.26

1

In the periodic table, rhenium is a group 7, sixth-row transition metal and is in the same group with manganese, technetium, and bohrium.

2

1.Introduction

In 1908, Ogawa found a new element that he called nipponium and incorrectly reported as the 43rd element (the 43rd element is the artificial element technetium). It is believed today that the element he discovered was in fact element 75, or rhenium. It was not until 1925, however, that rhenium was officially discovered by Noddack, Tacke, and Berg.

Notable featuresNotable features

◆Hard Lewis acidity

◆Soft Lewis acidity for activation of unsaturated hydrocarbons

◆Ability to activate C(sp2)-H and C(sp3)-H bonds

◆Low-valent rhenium carbonyl complexes promote oxidative cyclization.

3

2.C-C Bond Formation2.1. Nucleophilic Addition and Substitution

2.1.1. Friedel-Crafts Reactions.

+ Ph Cl

O ReBr(CO)5(10 mol%)

toluene, reflux, 2 hPh

O

(o:m:p=11:4:8)

ClO

ReBr(CO)5(10 mol%)

CH2ClCH2Cl, reflux, 2 h

O

86%

◆ReBr(CO)5 catalytically promotes Friedel-Crafts acylation

Kusama, H.; Narasaka, K. Bull. Chem. Soc. Jpn. 1995, 68,2379.

4

◆ Rhenium-catalyzed Friedel-Crafts alkylation of arenes

OMe

+ t-BuCl

(3.0 equiv)

ReBr(CO)5 (1.0 mol%)

CH2ClCH2Cl,84.C, 0.5 h

OMe

t-Bu

OMe

+t-Bu

t-Bu

66% 34%

5

◆ Diarylmethanes synthesized from 2 equiv of aromatic compounds and 1,3,5-trioxane

OMe

+

(24 equiv)

O O

O ReCl(CO)5 (5.0 mol%)

120.C, 10 h

OMe OMe OMe

OMe

+

70% 13%

Nishiyama, Y.; Kakushou, F.; Sonoda, N. Bull. Chem. Soc. Jpn. 2000, 73, 2779

Hua, R.; He, J.; Sun, H. Chin. J. Chem. 2007, 25, 132

6

◆Catalytic amount of Re2(CO)10 leads to monoalkylation only at the position ortho to the hydroxyl group

OH

+n-C6H13

Re2(CO)10 (2.5 mol%)

toluene, 150.C, 24 h

OH

n-C6H13

76%

OH

+Re2(CO)10 (2.5 mol%)

toluene, 115.C, 24 h

87%

n-C5H11

n-C5H11

OH

Kuninobu, Y.; Matsuki, T.; Takai, K. J. Am. Chem. Soc. 2009,131, 9914.

7

2.1.2. Nucleophilic Addition to Carbonyl and Related Compounds.

Ph R1

O

+ NC R2

(1.0 equiv)

ReBr(CO)5 (0.50 mol%)

neat Ph R1

NC R2

R1 R2 conditions Yield/%

H CN 110℃， 1.5 h 90

H CO2Et 110℃， 2 h 88

Me CO2Et 130℃， 70h 45

Zuo, W.-X.; Hua, R.; Qiu, X. Synth. Commun. 2004, 34, 3219.

◆ Knoevenagel condensation

◆ Rhenium-catalyzed allylation of aldehydes with allyltributylstannane

PhCHO + SnBu3ReCl(CO)5 (10 mol%)

benzene,80.C, 5 h Ph

OH

(1.2 equiv) 78%

Nishiyama, Y.; Kakushou, F.; Sonoda, N. Tetrahedron Lett. 2005, 46, 787.

8

n-C9H19CHO + Me3Si Ph

[ReBr(CO)3(thf)]2 (2.5 mol%)

AuCl (5.0 mol%)

CH2Cl2, 50.C, 3h

OH

n-C9H19

Ph90%(4.0 equiv)

◆ Formation of propargylic Alcohols via cocatalyst of AuCl and formation of propargylic alcohols

RCHO

+

Me3Si Ph

ReI + AuI OH

R

Ph

R=alkyl

ReI

R= Ar Ar

Ph

Me3Si Ph

Ar

Ph

Ph

◆Mechanism

Kuninobu, Y.; Ishii, E.; Takai, K. Angew. Chem., Int. Ed. 2007, 46, 3296.

9

◆ Highly enantioselective addition of diphenylzinc to aldehydes

RH

O

+ ZnPh2

(0.65 equiv)

ReCO

OCOC Ph

OH

Ph

ON

t-Bu

ZnEt(1.3 equiv)

(10 mol%)

toluene, 10 oCR

Ph

OH

Bolm, C.; Kesselgruber, M.; Hermanns, N.; Hildebrand, J. P.;Raabe, G. Angew. Chem., Int. Ed. 2001, 40, 1488.

10

2.1.3. Nucleophilic Addition to C-C Double and Triple Bonds.

◆ Addition of active methylene compounds to alkynes

R1 OC2H5

O O

R2

R3 H

cat. In(OTf)3

neat100-140 oC

R1 OC2H5

O O

R2

R3

yield 80%-99%

OEt

O OPh H

[ReBr(CO)3(thf)2] (3.0 mol%)

toluene, 50 oC,24hOEt

OH O

93%

+

(2.0 equiv) Ph

Nakamura, M.; Endo, K.; Nakamura, E. J. Am. Chem. Soc. 2003, 125, 13002.

Kuninobu, Y.; Kawata, A.; Takai, K. Org. Lett. 2005, 7, 4823

11

◆MechanismO

OEt

O

+ Ph Dcat. ReI

O

OEt

O

Ph D

(D:11%)

(D:86%)

O

OEt

O

+ Phcat. ReI

D

O

OEt

O

Ph

(D:66%)

(D:14%)

D

O

OH

R ReI

O

O

RReI

H

O

OH

RReI ReIII

O

R

OHO O

RReIII

H

O O

R

OH O

R

Mechanism A

Mechanism B

12

◆ Nucleophilic addition of active methylene compounds to activated alkynes

OMe

O OMeO2C H

ReBr(CO)5 (0.5 mol%)

toluene, 120 oC,10 h

+O OMe

O

O

94%

HO

MeO2C

OMe

O - MeOH

Zhao, W.-G.; Hua, R. Tetrahedron. 2007, 63, 11803.

13

2.2. Annulations2.2.1. Annulation viaAlkylidene Intermediates

◆Mechanism

R1

OSiR33

R2

Re

R1

OSiR33

R2

Re R1

OSiR33

R2

Re

H

R2

i-Pr3SiO

ReR1

-Re H

R2

i-Pr3SiO

R1

Kusama, H.; Yamabe, H.; Onizawa, Y.; Hoshino, T.; Iwasawa,N. Angew. Chem. Int. Ed. 2005, 44, 468.

◆ Rhenium complex ReCl(CO)5 catalyzes tandem cyclization of ω,ω-acetylenic dienol silyl ethers

OSii-Pr3ReCl(CO)5 (0.50 mol%)

MS4Ahv(250W super high pressure Hg lamp)

toluene, 16h

Hi-Pr3SiO

+

Hi-Pr3SiO

62% 30%

14

◆Substituted phenols generated by silyl enol ethers bearing a propargyl carboxylate moiety

i-Pr3SiO

OCOPh

ReBr(CO)5 (10 mol%)NaHCO3 (1.0 equiv)

toluene, 110oC, 3 h

OSii-Pr3

90%

◆Mechanismi-Pr3SiO

OCOPh

Rei-Pr3SiO

OCOPh

Re

OSii-Pr3

Re

OCOPh

OSii-Pr3

Re

OCOPh

OSii-Pr3

Re

OSii-Pr3

ReH B

-Re

OSii-Pr3

Saito, K.; Onizawa, Y.; Kusama, H.; Iwasawa, N. Chem.-Eur. J. 2010, 16, 4716.

15

◆ The construction of polycyclic ring skeletons by cycloisomerization of ene-ene-ynes

EtO2C

EtO2C

EtO2CCO2Et

ReCl(CO)5 (8.0 mol%)

toluene,80oC,24 h

CO2Et

CO2EtEtO2C

EtO2C

H

H

H H

◆Mechanism

EtO2C

EtO2C

EtO2CCO2Et

Re

Re

EtO2C

EtO2C

EtO2CCO2Et

Re EtO2C

EtO2C

EtO2CCO2Et

Re

ReEtO2C

EtO2C

EtO2C CO2Et

EtO2C

EtO2C

H

Re

CO2EtCO2Et

EtO2C

EtO2C

HH

CO2EtCO2Et

ReH

H

CO2EtCO2EtEtO2C

EtO2C

H

H

H H

-Re

Chatani, N.; Kataoka, K.; Murai, S.; Furukawa, N.; Seki, Y. J. Am. Chem. Soc. 1998, 120, 9104.

16

2.2.2. [2+2]-, [3+2]-, and [2+2+2]-Cycloaddition Reactions

◆[2+2]-Cycloaddition

+ MeO2C CO2Me

[ReBr(CO)3(thf)]2 (5.0 mol%)2,6-i-Pr2C6H3NC(10 mol%)

toluene, 115oC, 24h CO2MeCO2Me

79%(2.0 equiv)

Kuninobu, Y.; Yu, P.; Takai, K. Chem. Lett. 2007, 36, 1162.

◆Regio- and stereoselective synthesis of cyclopentene derivatives from β-keto esters and allenes

OEt

O O

+ PhRe2(CO)10 (2.5 mol%)

neat, 115oC, 30h

CO2Et

HO

Ph

85%

Yudha, S. S.; Kuninobu, Y.; Takai, K. Angew. Chem., Int. Ed. 2008, 47, 9318.

17

Re

D

O

R1

O

OR2

H

Re Re

O

OR2

OH

D

DR1

Re

O

OR2

OH

D

R1

D

Re

O

OR2

OH

DR1

CO2R2

HO

R1

D

D

O

CO2R2 O

COR2

HO

R1

DD

◆Mechanism

18

◆ Regioselective [2+2+2]-cycloaddition reactions

O O

OEt+ Ph

ReBr(CO)5 (5.0 mol%)DMA(20 mol%)

MS4A

toluene, 115oC, 5h

Ph

Ph

O

OEt

50%(4.0 equiv)

◆Mechanism

R1

O O

OR2

R3

M

R1

OH O

OR2

R3M

M= Re, Mn

R3R1

OH O

OR2

R3M

R3

-M

Path A

Path B

R1

O O

OR2

R3

M

M

R3

HO R1

CO2R2 R3

-M

R3O R1

H

H

CO2R2

R3

-H2OR3

R3

O

OR2

Kuninobu, Y.; Nishi, M.; Yudha, S. S.; Takai, K. Org. Lett. 2008, 10, 3009.

Yoshikai, N.; Zhang, S.; Yamagata, K.-i.; Tsuji, H.; Nakamura, E.J. Am. Chem. Soc. 2009, 131, 4099.

19

2.3. Coupling Reactions

◆Coupling reaction between alkyl iodides, carbon monoxide, and alcohols

I

+ CO + MeOH

Re2(CO)10 (5.0 mol%)K2CO3 (0.60 equiv)

hv(200 W high pressure Hg lamp)

THF, 25oC, 20 h

O

OMe

77%

◆ Olefin metathesis of terminal and internal olefins

cat. ReCl(CO)5cat. EtAlCl2

C6H5Cl, 90oC, 20 min67%

Kondo, T.; Tsuji, Y.; Watanabe, Y. Tetrahedron Lett. 1988, 29,3833.

Farona, M. F.; Greenlee, W. S. J. Chem. Soc., Chem. Commun.1975, 759.

20

2.4. Reactions Based on C-H Bond Activation◆C(sp3)-H borylation at the terminal position of alkanes under photochemical conditions

+O

BO

BO

O

ReCp*(CO)3 (2.4 mol%)CO (2.0 atm)

hv(medium pressure Hg lamp)

25oC, 56 h

BO

O

95%

Chen, H.; Hartwig, J. F. Angew. Chem., Int. Ed. 1999, 38, 3391.

◆ C(sp2)-H bond functionalization

N

H

t -Bu

+ Ph Ph

(1.0 equiv)

[ReBr(CO)3(thf)]2 (3.0 mol%)

toluene, 115oC, 24 h

HN

Ph

Ph

t-Bu

95%

Re

Re H

H

Nt-Bu Ph Ph

HNt -Bu

Ph

Re

Ph

H

N

Ph

Ph

t-Bu

95%

ReH-Re

Kuninobu, Y.; Kawata, A.; Takai, K. J. Am. Chem. Soc. 2005, 127,13498.

21

◆ Insertion of an Alkyne into the Formed M-C or M-H Bond

X

H

M

X

M H insertion into M-H

XM H

X

M

H

intramolecularcyclization

-M

reductiveelimination

-M

XH

X

cyclized product

simple insertionproduct

22

◆Intramolecular cyclization of aromatic ketimines and acrylates

NPh + CO2Et

[ReBr(CO)3(thf )2] (3.0 mol%)

toluene, 150 oC, 24hCO2Et

85%CO2Et

+ CO2Et

[ReBr(CO)3(thf )2] (3.0 mol%)p-anisidine (15 mol%)

toluene, 180 oC, 24hCO2EtO

(1.5 equiv)93%

(a)Kuninobu, Y.; Nishina, Y.; Shouho, M.; Takai, K. Angew. Chem., Int. Ed. 2006, 45, 2766.(b)Kuninobu, Y.; Nishina, Y.; Takai, K. Org. Lett. 2006, 8, 2891.(c)Kuninobu, Y.; Nishina, Y.; Kawata, A.; Shouho, M.; Takai, K.Pure Appl. Chem. 2008, 80, 1149.

O

OR

ArNH2

O

H2O

NAr

NHO

OR

Ar

Re(I)

NAr

Re H

O

OR

NAr

Re

O

OR

H

NO

OR

ArRe

H

◆Mechanism

24

◆ Insertion of polar unsaturated molecules into C-H bonds of aromatic compounds

(a)Kuninobu, Y.; Tokunaga, Y.; Kawata, A.; Takai, K. J. Am. Chem. Soc. 2006, 128, 202.(b)Kuninobu, Y.; Nishina, Y.; Nakagawa, C.; Takai, K. J. Am. Chem. Soc. 2006, 128, 12376.

[ReBr(CO)3(thf)2] (3.0 mol%)

CH2ClCH2Cl, reflux, 24hN

HN

97%

N

H

t-Bu

+ Ph N C O

Ph

NPh

+ Ph H

O

(1.0 equiv)

(2.0 equiv)

[ReBr(CO)3(thf)2] (2.5 mol%)MS4A

toluene, 115 oC, 24hO

Ph

Ph93%

N

H

t-Bu

[ReBr(CO)3(thf)2] (6.0 mol%)

toluene, reflux, 24h+ Ph Me

HN

Ph

Me

t-Bu HN

Me

Ph

t-Bu

+

Ph

O

t-Bu

25

◆ Olefinic C-H bond functionalization

Ph H

O

(3.0 equiv)

[ReBr(CO)3(thf)2] (2.5 mol%)MS4A

toluene, 115 oC, 24hN

NMe

+ + HSiEt3 N

NMe

Ph

OSiEt3

80%

Kuninobu, Y.; Fujii, Y.; Matsuki, T.; Nishina, Y.; Takai, K. Org. Lett. 2009, 11, 2711.

◆MechanismN

NMe

R

OSiEt3

ReI or MnI

N

NMe

H

N

NMe

MIII

H

RCHO

N

NMe

MIII

RO H

H2

HSiEt3

26Kuninobu, Y.; Yu, P.; Takai, K. Org. Lett. 2010, 12, 4274.

◆Diastereoselective synthesis of aminoindane derivatives

neat, 115oC, 24hN

Ph+ Ph

[HRe(CO)4]n(Re:5.0 mol%)

HN

Ph

Ph

88%1.5%

◆ Synthesis of cyclopentadienyl-rhenium (Cp-Re) complexes

Kuninobu, Y.; Nishina, Y.; Matsuki, T.; Takai, K . J. Am. Chem. Soc. 2008, 130, 14062.

NPh

+OR

O+

(1.0 equiv)

xylenes, 150 oh, 72h

R=2-ethylhexyl

O

OR

ReOC

CO

CO

94%

1/2 Re2(CO)10

(0.5 equiv)

27

2.5. Reactions Initiated by C-C Bond Cleavage

◆Ring expansion reaction of cyclic β-keto estersO

OEt

O

+ Ph

[ReBr(CO)3(thf )]2 (2.5 mol%)PhCH2NC(5.0 mol%)

neat, 40oC, 24 h

O

Ph

OEt

O

97%(1.2 equiv)

O

OEt

O OH

OEt

O

R

ReHO

OEt

OR

ReI

O

R

OEt

O

ReO

R

OEt

O

ReHO

R

OEt

O

O

OEt

HO R

HO

R

OEt

O

Kuninobu, Y.; Kawata, A.; Takai, K. J. Am. Chem. Soc. 2006, 128, 11368.

28

O

OEt

O

+ Ph

[ReBr(CO)3(thf)]2 (2.5 mol%)MS4A(100 wt% Re-cat.)

neat, 40oC, 24 h

O

Ph

OEt

O

(1.0 equiv)

HO

Ph

OEt

O

TBAF(20 mol%)

neat, 40oC,4h

O

Ph

O

90%

◆ Synthesis of bicyclic compounds

Kuninobu, Y.; Morita, J.; Nishi, M.; Kawata, A.; Takai, K. Org. Lett. 2009, 11, 2535.

29

◆2-pyranone derivatives are produced by intramolecular cyclization

[ReBr(CO)3(thf)]2 (2.5 mol%)MS4A(200 wt%-Re cat.)

O

OEt

O

+ Ph Ph

(1,0 equiv) (1.2 equiv)

toluene, 180oC, 24h

O

O

Ph

Ph96%

Kuninobu, Y.; Kawata, A.; Nishi, M.; Takata, H.; Takai, K.Chem. Commun. 2008, 6360.

R1

R2

O

OEt

O

R1

R2

OH

OEt

O

R3

Re

R3

CO2EtR2

O

R1

H

CO2EtR2

R3ReR1

O

R3R1

O

R2 CO2Et

H

Re

OR2 CO2Et

R3R1

R1

R3O

R2

CO2Et

+R1

R3O

CO2Et

R2

◆Mechanism

30

Conclusion◆Prior to 2000, rhenium carbonyl complexes were used as hard Lewis acid catalysts to promote C-C bondformation reactionsI.In addition, C-O, C-S, and C-Se bond-forming reactions and reduction of carboxylic acids andCO2 have also been reported. ◆Since about 2000, rhenium carbonyl complexes have also been employed as soft Lewis acids. Cyclization reactions and nucleophilic additions of carbon nucleophiles to alkynes or allenes have been achieved via the activation of the unsaturated substrates. C-Si, C-N, and C-O bonds have also been constructed using rhenium carbonyl catalysts. ◆Since 2005, rhenium carbonyl catalyzed transformations via C-H and C-C bond cleavage, which are the key reactions for highly efficient transformations, have been realized.At present,◆It is clear that rhenium carbonyl complexes have a variety of catalytic activities. In the future, it is expected that more information about the reactivities of rhenium carbonyl complexes will be clarified, and additional novel as well as more typical reactions catalyzed by rhenium carbonyl complexes will be discovered.