en route to photoactivatable enediynesvpopik.uga.edu/uga_2010.pdfkostikov,a.; popik, v.v....

UGA, August 10, 2010

Light Chemistry:

Photoactivated Antibiotics, Photolabile

Protecting Groups, Photo Click Ligation, etc.

Vladimir V. Popik


O

H3CSSS

O

HO

HN

O

OCH3

O

CH3

NH

O

OHO

O NH

OCH3

O

OH

S

CH3

O

CH3I

OCH3H3CO

O

O

OHH3CO

HOH3CO

Natural Antitumor Enediyne Antibiotics

Calicheamicin 1

Dynemicin A

Esperamicin

Neocarzinostatin

O

O

O

OH

H3C

OCH3

O

O O

O

O

HO

OH

NHCH3

O

H3CSSS

O

HO

HO

HN

O

OCH3

O

CH3

NH

O

OHO

O NH

OCH3

O

OH

CH3S

CH3

OH

OH

O

O OH

HNO

CO2H

CO2H

Bergman Cyclization

C

Myers-Saito Cyclization


Photochemical Triggering of Bergman Cyclization

Ring Contraction

Stable ½ = 18 h at 360C

X h

Generation of a π-system

X Yh h

X

Yn nn

Removal ofblocking device

hBlockinggroup

activator

Poloukhtine, A.; Karpov, G.; Popik V.V. Curr.Topics Med.Chem., 2008, 8, 460;

Polukhtine, A.; Karpov, G.; Pandithavidana, D. R.; Kuzmin, A.; Popik, V.V. Aust. J. Chem. 2010, 63,1099


Synthesis of 2-Diazo-1,3-dioxocycloundeca-6-en-4,7-diyne

I

R R

SiMe3

b

R = NH2

R = N3Et2a

R = N3Et2R = I

c

d

SiMe3

X

X = H, OH

R = Oe

R2

OR1

O

O

f

R1= H, R

2= Me3Si

R1= TBS, R

2= Me3Si

R1= TBS, R

2= H

R1= TBS, R

2= I

g

h

i

ok

TBSO

O

I

O

X

X= H, OTBS

X= H, OH

X = O

m

n

j

OH

OTBSl

O

O

N2

(a) NaNO2, HCl, Et2NH, 86%; (b) HC CSiMe3, Pd(PPh3)2Cl2, CuI, PPh3, Et3N, THF, 400C; (c) CH3I, 1400C, 94% over two

steps; (d) HC C(CH2)3CH2OH, Pd(PPh)2Cl2, CuI, PPh3, Et3N, THF, r.t., 98%; (e) Dess-Martin periodinane, CH2Cl2, 82%; (f)

LDA, THF, -780C, ethyl acetate, 90%; (g) TBDMSCl, CH2Cl2, DMAP, 90%; (h) K2CO3, methanol, 97%; (i) I2, morpholine,

benzene, 500C, 91%; (j) DIBAL, CH2Cl2, 87%; (k) CrCl2, NiCl2, THF, 76% (both diastereomers); (l) Dess-Martin periodinane,

CH2Cl2, 92%; (m) HFaq, CH3CN, 88%; (n) Dess-Martin periodinane, CH2Cl2, 84%; (o) TosN3, DBU, CH2Cl2, 84%


Enediyne Ring Contraction by photo-Wolff reaction

Stable at 250C

84oC > 15 h

= 50 s

(MeOH)

No decomposition for 7

days at 840C


Tautomerization - Myers-Saito Cycloaromatization

G0= -11.7 kcal/mol G0 ~0

CO2R

O

O

CO2Me

C

H

O

CO2MeOH

CO2Me

D CO2R

OD

(CH3)2CHOD

kH / kD = 2.18

Rate-limiting

Very fast25oC < 100 ms

Karpov, G.; Kuzmin, A.; Popik, V. V.

J.Am.Chem.Soc. 2008, 130, 11771

Karpov, G.; Popik, V.V. J.Am.Chem.Soc.

2007, 129, 3792

B3LYP / 6-31++G(dp):


C

O

CO2R

OH

OO

C O

+

OH

CO2R

+

Enediyne Ring Contraction by photo-Wolff reaction

O

N2

O

i-PrOH

h

CO2R

OHOH

CO2R

+

3:1

0oC < 1 min


Photochemical Generation of Enediyne Triple Bond

= 0.2 – 0.9Quantitative

0 200 400 600 800 1000

-0.10

-0.05

0.00

0.05

0.10

0.15

380 nm

645 nm

Time / ps

IGNORES:

triplet sensitizers

triplet quenchers

singlet quenchers

radical traps

cationic traps

carbene traps

Poloukhtine, A.; Popik, V.V. J.Phys.Chem. A 2006 110 , 1749


Photo-generation of Enediyne Triple Bond

300 = 0.46

QuantitativeStable at 900C

Poloukhtine, A.; Popik, V.V. J.Org.Chem. 2005, 70 , 1297;

Poloukhtine, A.; Popik, V.V. Chem.Comm. 2005, 617


Generation and Cyclization of 9-Membered Ring Enediyne

i-PrOH

OH

25oC = 98 min

kH / kD = 5.18

Pronounced primary KIE in isopropanol –d8

OH

290 300 310 320 330

0.0

5.0x10-4

1.0x10-3

1.5x10-3

H = 13627 ± 216 cal mol-1

S = -30.66 ± 0.61 cal mol-1 deg-1

Observ

ed R

ate

/ s

-1

Temperature / oK

0 2 4 6 8 10 12 14

0.0

5.0x10-5

1.0x10-4

1.5x10-4

Ra

teo

bs / s

- 1

[2-Propanol] / M

k = (1.108 ± 0.058) 10-5 M

-1s

-1

Rate-limitingFast

2.90

Pandithavidana, D.R.; Poloukhtine, A.; Popik, V.V. J.Am.Chem.Soc. 2009, 131, 351

K ~ 10-11


9-Membered Ring Enediyne

Stable at 250C !

350 = 0.50

i-PrOH

@ 700C

= 6 h in neat i-PrOH

= 13 h in i-PrOH : H2O (1:1)

2.94


Photochemical Generation of EneYne-Allene

25oC ~ 5 min

0 200 400 600 800 1000 1200 1400 1600 1800

1.00

1.05

1.10

1.15

1.60

1.65

1.70

1.75 Cyclohexadiene / THF

k=(3.4±1.0)x10-3s

-1

k=(2.74±0.05)x10-3s

-1

Ab

so

rba

nce

@ 2

32

nm

Time / s

i-PropanolKuzmin, A.V.; Popik V.V. Chem.Commun. 2009, 5707


Aza-Enediyne

N

Ts

OH

R

N

Ts

OH

H

R = C6H7

OH OH½ 40oC= 154 h

R

N

Ts

OH

R = C7H7

CH3

550C

N

Ts

OH

1/2 ~ 3 h

(400C)

O

N

Ts

OH

½ = 30 min (400C)


Acid-Catalyzed Bergman Cyclization

N

Ts

OH

CN

H

Ts

HO

AH

RO

H

-H

O

N

Ts

OH

N

Ts

OH

HR

O

N

Ts

OHR

MeOH

O

N

Ts

OMeMe

-H

N

Ts

OH

Poloukhtine, A.; Rassadin, V.; Kuzmin, A.; Popik, V.V. J. Org. Chem. 2010, 75, ASAP article jo01238x.


Photonuclease Activity of Photoswitchable Enediynes

N2

O

O

Relaxed

Linear

Supercoiled


Light Penetration in Mammalian Tissues

Muscle penetration depth of light

Wavelength (nm)

Wavelength (nm)

UV Spectrum of Oxyhemoglobin

EE’

S0

S1

ENon-Resonant Two-photon

Excitation


Two-photon Photochemistry of Enediyne Precursor

0 1000 2000 3000

0.0

0.5

1.0

Yie

ld o

f E

nediy

ne

Time / s

O

O

O

O

O

800 nm

94 fs pulses, 1 kHz

MeOH

0.4 0.8

0.0

0.4

0.8

-3.5 -3.0

-1.5

-1.0

-0.5

0.0

Slope = 2.067 ± 0.020

Lo

g (

Ye

ild

of 2

)

Log (Pulse Energy)

Yile

d o

f E

ne

diy

ne

(1

0 m

in)

Pulse Energy / mJ

= 0.8 GM

100

20

100

0(1 )

fs

WR

fs

I dt t

C C e

Urdabaev, N.K.; Poloukhtine, A.; Popik,V.V. Chem.Comm. 2006, 454


O

MeO OMe

Nonresonant Two-photon Photochemistry

O

OMe OMe

= 0.5 GM

O

Me2N NMe2> 15 GM

= 0.02 GM

O O

N2

N N

O O

N2

= 5 GM = 407 GM


10-1

10-3

10-5

10-7

10-9

10-11

10-13

1x102

1x103

1x104

log

(kO

BS)

/ s

-1

[H+] / M

Arumugam, S.; Popik, V.V. J.Am.Chem.Soc. 2009, 131(33), 11892-9.

= 12 s

o-Quinone Methides

0.00 0.02 0.04 0.06 0.08 0.100

1x103

2x103

3x103

4x103

5x103

6x103

kquench

= (4.60 ± 0.56)*104 M

-1s

-1

kO

BS / s

-1

[CH2=CH-OEt] / M

kH2O/ kD2O = 1.85±0.14

= 7.4 ms


Photoactivatable Antimitotic Agents

O

O

O

O

OH

OO

O

HO

NH

O

O

R

O

O

R'

O

O

O

O

OH

n

PPG

O

NH

O

O

R

O

O

O

O

O

OO

OH

OO

O

HO

NH

OH

O

R

O

O

R'

h , H2O

-CO2

Taxol

(paclitaxel)

O

SB

R

Ar

R

h

R

Ar

R O SBROH

OHR

Ar

RHO SB+

+


H2O

+ ROH

OH

OR

hO

OH

OH

OEt

O OEt

O

OR

H

(2-Hydroxynaphth-3-yl)methyl Cage

EtOH

95%

OH

97%

O

OH

NHBoc

HO

O

O

OR

HO N

NH

O

O

OH

O

O

O

OH

89% (98%)

96%

97%

96%

92%(91%)

Kulikov, A.; Arumugam, S.; Popik, V.V. J.Org.Chem. 2008, 73(19), 7611.


2,5-Dihydroxybenzyl Cage

O

OH

O

O

ROH +

OH

OH

OR

h

250 300 350

0.0

0.5

Ab

so

rba

nce

Wavelegth / nm

MeOH or

MeCN/H2O

OH

CO2H

CO2H

H3C

H3CH3C

OHCl

80%

=0.2 - 0.3

100%

= 0.31

85%

= 0.5

55%

= 0.06 Kostikov, A.; Popik, V.V. J.Org.Chem. 2007, 72, 9190


Photolabile Protection for Glycols and Carbonyl Compounds

hO

OBnO

OBnOBn

O

OH

HO

O

OBnO

OBnOBn

O

O

O

[H]O

HOBnO

OBnOBn

HO

OH O

O R

R O O

OHR

R

O

R R

O+h

H2O

OHO O

300 nm

O O

O R

R

O

[H]

Kostikov, A.; Popik, V.V. J.Org.Chem. 2009, 74, 1802.


Photo-activation of Anomeric Position for Glycosylation

O

RORO

O

OR

RO

HO

O

RORO

O

OR

ROh

O

RORO

OR

RO

O

+

O

RORO

O

OR

ROO

RO

OR

OR

OR

HOO

RO

OR

OR

OR


Hetero-Diels-Alder Reaction of o-Quionone Methides

k > 104 M-1 s-1


Hetero-Diels-Alder Photo-Click

patterned irradiation


“Strain-Promoted” Azide Click Reaction

Conventional “Click” reaction

R= H, needs Cu+ catalysis

Cu+ is cytotoxic!

R= Alk or Ar – too slow

“Strain-promoted Click” reactiondoes not needmetal catalyst

Wittig, G.; Krebs. A. Chem. Ber. 1961, 94, 3260-3275;

Bertozzi et al. J. Am. Chem. Soc. 2004, 126, 15046-15047;

Boons et al. Angew. Chem. Int. Ed. 2008, 47, 2253-2255.


Metal – Free Azide Click on the Surface


Metal – Free Click Derivatization of Nanopartcles


Photochemical Generation of Dibenzocyclooctynes

250 300 350 400

0.0

0.5

1.0

1.5

2.0

(nm)


Using Photo-Click Reaction for the Live Cells Labeling

O

AcOAcO

HNAcO

OAc

ON3

N3Cell

N3

N3

N3

BuO

O

+

Fluorescent Tag

Upon irradiation

In the dark

Ac4ManNAz

In collaboration with Dr. Boons

Poloukhtine, A.A.; Mbua, N.E.;

Wolfert, M.A.; Boons, G.-J., Popik,

V.V. J.Am.Chem.Soc. 2009,

131(43), 15769


Photo-Click on the Brushes

1. Patterned Irradiation2. Rhodamine B– N3

3. Flood Irradiation4. Oregon Green – N3

Orski, S.V.; Poloukhtine, A.A.; Arumugam, S.; Mao, L.; Popik, V.V.; Locklin, J. J. Am. Chem. Soc. 2010, 132, ASAP article ja05066t.

In collaboration with Dr. Locklin

10 μm 10 μm 10 μm

(a) (b) (c)


The Team

• Dr. Selvanathan Arumugam• Alexander Kuzmin• Emmanuel Nekongo• Dewey Sutton• Natalia Zhegalova• Kevin Wickware

Alumni

• Dr. Gregory Karpov• Dr. Alexey Kostikov (PhD 2008)• Dr. Dinesh Pandithavidana (PhD 2009)• Dr. Andrei Poloukhtine• Dr. Victor Sorokoumov

Acknowledgements

Collaborators

Professor Geert-Jan BoonsMbua Eric NgalleDr. Margreet WolfretDr. Jun Guo

Professor Jason LocklinSara Orski

Money

• National Science Foundation (CHE-0631210; CHE-0842590)

• Georgia Cancer Coalition Distinguished Cancer Scholar Award

• Petroleum Research Fund (43444-AC4; 48353-AC4)

• The University of Georgia

en route to photoactivatable enediynesvpopik.uga.edu/uga_2010.pdfkostikov,a.; popik, v.v....

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