1,5-h shift

1,5-H shift

文献汇报

何玉萍2010-11-06

R=CH3, X=- 45h yield 91%R=CH3, X=CH2 90h yield 95%R=OCH3, X=- 20h yield 77%R=OCH3, X=CH2 20h yield 90%

T.L., D. N. Reinhoudt, 24, 3923,1983.

N

RO

CF3

n-BuOH

refulx O

NX

H CF3

X

N

RO

CF3O

NX

H CF3

XN+

RO-

CF3

XN+

R O-

XH

H

CF3H

1,5-H shift

O

N

O

OR

N

其中类似 CF3 的强吸电子基团是必不可少的

均不能发生类似的反应

N

CF3

N Ph CH3 118℃5d

H3CH3C

NH

CF3H

N

CF3

N Ph CH3H3CO

n-BuOH

n-BuOH 118℃OR MeCN 81℃

X

14% 66%

X

√

1,R1=CH3, R2=CF3

2,R1=H, R2=H3,R1=H, R2=CH3

4,R1=H, R2=C6H5

Lawesson reagent

D. N. Reinhoudt

R2 可以不必是强吸电子基团

R1

N

O

R

PH3COS

PS

S

SOCH3 R1

N

S

R

N

S

H R2

HR1

tol uene115℃

N

O

H R2

HR1

R1

N

O

RR1

N

S

R

N+

R

S-

H

H1,5-H shift

N+

R

S-

R1

R1H

S

N

H R

H

Mechanism

Tetrahedron.1984,4309-4312

Solvent Yield

5a Toluene 54%/32%

1-butanol cis 74%

5b X

5c X

7a toluene 3d X

1-butanol 44%/42%

MeCN/ZnCl2 47%/12%

7b 1-butanol 6dMeCN/ZnCl2 3d

X

toluene/ZnCl2 11%/26%

7c tolueneCH3COOH 12d

X

9 1-butanol 10dMeCN/ZnCl2 3d

X

10 1-butanol 67%

11a11b11c

1-butanol 2htoluene 35h

82%78%84%

D. N. Reinhoudt, JOC, 49, 2, 1984.

N

Mechanism

总结 :1, 溶剂效应 ( 极性溶剂更容易促进反应 )2,lewis 酸可以促进反应3

4 任何可以稳定 1,5- 偶极的基团都可以促进反应

N N

O

> >

1,6H shiftN+

C- CH2R2

NX

R1

H

R2

H

H

X

R1

stereo-

mutation

N+

C- R1

X

CH2R2

N

R1R2H2C

5a R1=R2=COOEt, X=_

7a R1=CN, R2=Ph, X=_

7b R1=CN, R2=Ph, X=CH2

H

N

RR

XH

H

H

N+

RR

XH

H

a

[1,6] H

b

[1,5] H

C-

N+X

H

RRH

C-

N+X

H H

RR

[1,2] H

NX

RR

10, R=COOEt, X=_

11a, R=CN, X=_

11b, R=CN, X=CH2

11c, R=CN, X=O

b

与 5 不同

D. N. Reinhoudt, Tetrahedron Letter, 1984, 25, 19, 2025.

N

NC OHH

H

NC X

N N+

C-NC

XH

N+

Y-

NC

H

NC

(CH2)4Y

H

X=OAc,OTS,Cl

acetyl chloridep-Toluenesulfonyl chlorideDMF 50℃

3a

Synthesis, 2005, 2161.Synthesis, 2007, 2872.

Daniel Seidel, Org. Lett. 2009, 11, 129.

rt

illustrate for the first time that such a reaction is amendable to enantioselective catalysis.

Dainel Seidel, J. Am. Chem. Soc. 2009,131,13266

the first example of a catalytic enantioselective hydride shift/ring closure reaction cascade

the first example of a organocatalytic enantioselective hydride transfer/ring closure reaction cascade

J. Am. Chem. Soc. DaeYoungKim, 2010, 132, 11847

Daniel Seidel, J. Am. Chem. Soc. 2008, 130, 416

Sames, J. Am. Chem. Soc. 2005, 127, 12180.

无杂原子

Sames, Org. Lett. 2005, 7, 5429.

O HO

EE

lewis acid

rt O O

EE

H

[1,5] H

O+

EE

H O M-

M

C-O 形成

1 ， BF3.Et2O 是催化该反应最好的 lewis acid2 ，所得产物不一定全是螺环，如 15 ， 17. 但需要更强的 lewis acid TiF4 。3 ， ketone 19 也可以参与类似的反应。只是还未找到更为有效的催化剂。

OO

E

E

2

OO

E

9

OO

22

E E

OO

23 20

O

O

EE

1

O

O

E

8

O

O21

EE

O

O22

O

19

Me Me

ArMe

O

Me Me

ArMe

-6.79 -2.33 +2.42 +0.13 +1.21

O

Me Me

ArMe

Me Me

OAr Me

Ar=4-(MeO)C6H4

4 : 96

30% mmol BF3.Et2O

CH2Cl2,rt, 5h

DFT caculation

No reaction Low yieldexcellent yield

O

E

PtXn 5mol%

MeCN, 120℃ O

EUnactivated teminal alkynes

Lewis acid activation of the terminal alkyne and the subsequent hydride transfer

Sames, J. Am. Chem. Soc. 2009, 131, 16525.

PtI4 more electrophilic and more accessible to the alkyne

Greater hydride PtI4NoReationK2PtCl

苄醚

Deuterium Labeling Studies and Proposed Mechanisms

H

O Ph

DD

H

O Ph

DD

I4Pt

O+Ph

D

H-I4Pt

I4Pt

H

D

DPhO

D

D

Ph

O

PtI4

Ph

D D

O+Ph

D

D PtI4-

I4Pt

D

DPhH

Path B

vinylideneformation

Path A

alkyneactivation

[1,6] H [1,5] H

C-C bondformation

C-C bondformation

[1,2]H

Sames, Org. Lett. 2009, 11, 2972.

less active need stronger activation

the aryl alkyl ethers were less reactive in comparison to the dialkyl ethers

no reaction was observed in theabsence of catalyst under these conditions

Akiyama, Org. Lett. 2010, 12, 1732.