Tabela de pKa do Prof. David Evans

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pKa's of Inorganic and Oxo-Acids Substrate

pKa H2O (DMSO)

INORGANIC ACIDS (32)

15.7

H3O+

-1.7

H2S

7.00

HBr

-9.00 (0.9)

HCl

-8.0 3.17

HOCl

7.5

H2O (DMSO)

O X

(1.8) (15)

HClO4

-10

HCN

9.4

(12.9)

HN3

4.72

(7.9)

OH

X= CH3 CH2NO2 CH2F CH2Cl CH2Br CH2I CHCl2 CCl3 CF3 H HO C6H5 o-O2NC6H4

4.76 (12.3) 1.68 2.66 2.86 2.86 3.12 1.29 0.65 -0.25 3.77 3.6, 10.3 4.2 (11.1) 2.17

HSCN

4.00

H2SO3

1.9, 7.21

m-O2NC6H4

2.45

H2SO4

-3.0, 1.99

p-O2NC6H4

3.44

o-ClC6H4

2.94

m-ClC6H4

3.83

p-ClC6H4

3.99

HNO3

2.12, 7.21, 12.32 -1.3

HNO2

3.29

H2CrO4

-0.98, 6.50

o-(CH3)3N+C6H4 1.37 p-(CH3)3N+C6H4 3.43

CH3SO3H

-2.6

(1.6)

p-OMeC6H4

CF3SO3H

-14

(0.3)

NH4Cl

9.24

B(OH)3 HOOH

H3PO4

Substrate

CARBOXYLIC ACIDS

H2O

HF

pKa

Substrate

4.47

pKa H2O (DMSO)

ALCOHOLS

Substrate

O

15.7

(31.2)

MeOH i-PrOH

15.5

Ph

16.5

(27.9) (29.3)

t-BuOH

17.0

(29.4)

Ph

c-hex3COH

24.0

CF3CH2OH

12.5

(23.5)

9.3

(18.2)

9.95

(18.0)

(CF3)2CHOH C6H5OH

8.4

p-O2NC6H4OH

7.1 10.2

2-napthol

Ph

+

OH

-7.8 OH

Ph

CH3

Ph

O+

Ph

(10.8) (19.1)

Me

11.6

cis-CO2H

1.92, 6.23

Me

O+ H H

-2.05

O+

-2.2

+

H

OH

OH

11.3 (20.1)

-1.8

S

Me

Me

Ph OH

N O H

OH

N

N+ OH

8.88 (13.7) (NH) (18.5)

0.79

(+1.63)

Me N

Me

OH

(+5.55)

Me

Me

SULFINIC & SULFONIC ACIDS O

9.23

-3.8

O+

Me

OH

4.25 3.02, 4.38

-6.5 Me

H

(17.1)

PEROXIDES

R= H trans-CO2H

-6.2

H

O Ph

-12.4 OH

OH

OXIMES & HYDROXAMIC ACIDS N

N+

+

m-O2NC6H4OH p-OMeC6H4OH

pKa H2O (DMSO)

PROTONATED SPECIES

HOH

O R

Chem 206

MeOOH

11.5

CH3CO3H

8.2

Me

O S

OH

-2.6

O Ph

S

2.1 OH

*Values 14 for water and >35 for DMSO were extrapolated using various methods. For a comprehensive compilation of Bordwell pKa data see: http://www.chem.wisc.edu/areas/reich/pkatable/index.htm

pKa Table.1 11/4/05 1:43 PM

D.H. Ripin, D.A. Evans pKa H2O

Substrate

(DMSO) Substrate

pKa

PROTONATED NITROGEN N+H4

9.2

EtN+H

10.6

3

i-Pr2N+H2 Et3N+H PhN+H3 PhN+(Me)

(10.5)

11.05 10.75 (9.00)

2H

4.6

(3.6)

5.20

(2.50)

Ph2N+H2

0.78

2-napthal-N+H3

4.16

H2NN+H3

8.12

HON+H3

H2O (DMSO)

Quinuclidine

11.0

Me Me

H2N

N

(26.5)

AMIDES & CARBAMATES

(9.80)

R= H (23.5) CH3 15.1 (25.5) NH2 Ph (23.3) CF3 (17.2) (urea) NH2 (26.9) OEt (24.8)

N+H2 8.36

O

N-Me morpholine

R

7.38

NO2 +

O2N

NH3

-9.3

NO2

O

Et

N+ H

DABCO

O

2.97, 8.82 (2.97, 8.93)

N+

N H

6.90, 9.95

+NH 3

+NH

3

Proton Sponge PhCN+H

+NH

3

-9.0, 12.0 (--, 7.50)

(21.6)

O

O

Ac2NH

8.30

O

NH

( )n O

(20.8) O

NH

Ph

(17.9)

R

N H NSO2Ph NH2

H N

H N

GUANIDINIUM, HYRDAZONES,- IDES, & -INES N+H2 Me2N

(13.6)

NMe2 O

Ph

NNH2 Ph

DBU

(26.1)

(12) (estimate)

N H +

N H

N H

9.2

NH HN

R= H (PPTS) t-Bu Me Cl, H

6.95

O

+

N

N

(19.8)

N

(13.9) X= O (24.4) X= S (27.0)

S H

(29.4) Me

NMe 5.21 (3.4) (0.90) H 4.95 O NH NH N (12.1) N + (18.4) (4.46) 6.75 H Me R -10 0.72 *Values 14 for water and >35 for DMSO were extrapolated using various methods.

(15)

NH

N

H

H

+

NH

(18.6)

X

S

DMAP Me2N

N HN

N +

(23.0)

NH

X= O (14.8) X= S (11.8)

(17.2)

PROTONATED HETEROCYCLES

(16.4)

N

(11.9)

X= O (24) X X= S (13.3)

N H X

PhSO2NHNH2 PhNHNHPh

H N

N

Me

(18.9)

(20.95)

N

(21.6)

NHNH2

R

O

(17.3) (15.0)

R= Me Ph

HETEROCYCLES

(17.5) R = Me Ph (16.1) CF3 6.3 (9.7) MeSO2NHPh (12.9) RSO2NH2

O

n= 1 (24.1) n= 2 (26.4)

(14.7)

8.88 (13.7) (NH)

OH

SULFONAMIDE

N

Bn

O

NH

O

NH

O

H H3N+

12 (20.5)

Ph

O NH

pKa H2O (DMSO)

Substrate

HYDROXAMIC ACID & AMIDINES

IMIDES

HN3 4.7 (7.9) NH3 (41) 38 i-Pr2NH (36 THF)) 26(THF) (30) TMS2NH PhNH2 (30.6) Me Ph2NH (25.0) Me NCNH2 (16.9) NH (37) NH (44)

O

Morpholine

pKa H2O (DMSO)

Substrate

AMINES

5.96 H

N+

Chem 206

pKa's of Nitrogen Acids

N+ Me Me

(16.5) i-Pr

N H

Me

For a comprehensive compilation of Bordwell pKa data see: http://www.chem.wisc.edu/areas/reich/pkatable/index.htm pKa Table.2 11/4/05 1:43 PM

N+

i-Pr

(24)

D.H. Ripin, D.A. Evans

pKa H2O (DMSO)

Substrate

pKa H2O (DMSO)

Substrate

HYDROCARBONS O

53

(Me)2CH2

51

CH2=CH2

50

CH4

48 46

(56)

43

(44)

t-BuO

O

Me

O

PhH

41

Ph2CH2

33.5 (32.2)

(43)

31.5 (30.6) 24 (28.8) 23

PhCCH XC6H4CH3 X= p-CN

(30.8)

p-NO2

(20.4)

O

13

S

MeO

(15.7)

(20.1)

H2

Et O

i-Pr

O i-Pr

(20.9)

(26.6) Ph

Me2N

O SPh O N+Me3

(25.9) (24.9)

O CN

N

O

(18.2)

(18.0) Me2N

(17.2)

Me

S

~36

(25.7) Me2N

X=

19-20 (27.1)

O

(28.3)

n

Me

n=

i-Pr O

Ph

O

X

(26.3)

[30.2 (THF)]

Ph

LiO

t-Bu O Ph

O

15

Et

9

(26.5) (19.8) (18.7) (13.3) (12.5)

(27.7)

S

O

Et2N

20

X= H Ph SPh COCH3 SO2Ph

O

Me2N

Me

X

(14.2)

OMe

(26.9) Me

Me

O

11

MeO

(26.1) Me

(20.0)

AMIDES

p-COPh Me

N+Me3

Me O

PhCH3

HCCH

(23.6)

EtO

43

Ph3CH

Ph

O

O

O Me

O EtO

pKa H2O (DMSO)

Substrate

KETONES

24.5 (30.3)

t-BuO

pKa H2O (DMSO)

Substrate

ESTERS

(Me)3CH

CH2=CHCH3

Chem 206

pKa's of CH bonds in Hydrocarbons and Carbonyl Compounds

X

X= H CH3 Ph COCH3 COPh CN F OMe OPh SPh SePh NPh2 N+Me3 NO2 SO2Ph

(24.7) (24.4) (17.7) (14.2) (13.3) (10.2) (21.6) (22.85) (21.1) (16.9) (18.6) (20.3) (14.6) (7.7) (11.4)

H OMe NMe2 Br CN

(24.7) (25.7) (27.5) (23.8) (22.0)

4 5 6 7 8

(25.1) (25.8) (26.4) (27.7) (27.4)

O

O

O

(28.1)

(29.0)

(25.5)

O

(32.4) Me

Me

Me

*Values 14 for water and >35 for DMSO were extrapolated using various methods. For a comprehensive compilation of Bordwell pKa data see: http://www.chem.wisc.edu/areas/reich/pkatable/index.htm

pKa Table.3 11/4/05 1:44 PM

pKa's of CH bonds at Nitrile, Heteroaromatic, and Sulfur Substituted Carbon

D.H. Ripin, D.A. Evans

pKa H2O (DMSO)

Substrate

NITRILES NC

X=

(31.3) (32.5) (21.9) (10.2)

11

(17.1) (13.1) (11.1) (28.1) (20.6) (20.8) (12.0)

MeSCH2SO2Ph

(23.4)

PhSCHPh2

(26.7)

(PhS)3CH

(22.8)

(PrS)3CH

(31.3)

N

N

(28.2)

Ph

(26.7)

Ph

(23.0)

N+

Ph

(25.2)

O-

O

S

(30.2)

Ph

(30.0)

Ph

(35.1) (29.0) (29.0)

O

Ph

S

X

X= H Ph SOPh

(33) (27.2) (18.2)

O

Ph

(24.5)

S

CHPh2

SULFONIUM Me3S+=O Ph

S+

(18.2) (16.3)

CH2Ph

SULFIMIDES & SULFOXIMINES

Ph

Ph CO2Me CN RSCH2CN R= Me Et i-Pr t-Bu

(30.7) (20.8) (19.1) (24.3) (24.0) (23.6) (22.9)

PhSCH=CHCH2SPh (26.3) BuSH 10-11 (17.0) (10.3) PhSH ≈7

S

Ph O Ph O Ph O Ph

X= H CH3 t-Bu Ph CH=CH2 CH=CHPh CCH CCPh COPh COMe OPh N+Me3 CN NO2 SMe SPh SO2Ph PPh2 O

Ph

S

S

S

(22.3) CHPh2 O

S

(27.6) (30.7)

Me

(24.5)

CF3 O

(33)

CF3 O

Me NMe Me N+Me2

(14.4)

Me NTs

O

CH2Cl

CF3

Et

S

(31.1) Me O

(18.8) Me O

(21.8)

S

i-Pr O

(26.6)

S

O

(20.7)

O S

(32.8) Et

(PhSO2)2CH2Me

*Values 14 for water and >35 for DMSO were extrapolated using various methods.

pKa Table.4 11/4/05 1:44 PM

(29.0) (31.0) (31.2) (23.4) (22.5) (20.2) (22.1) (17.8) (11.4) (12.5) (27.9) (19.4) (12.0) (7.1) (23.5) (20.5) (12.2) (20.2)

O

S

NTs

S

X

O R

R= Me i-Pr O

O S

Ph

NTs

X

X=

X

Me

S N

S

X= H Ph SPh

S

(30.1)

O

S

(PhS)2CHPh

Ph

Me

Me

(30.5) S H

SULFONES

O

(30.8) (20.8) (18.7) (16.9) (11.8) (30.8) (20.5) (11.0) (24.9)

S

Substrate pKa H2O (DMSO)

SULFOXIDES

PhSCH2X X= Ph CN COCH3 COPh NO2 SPh SO2Ph SO2CF3 POPh2

HETERO-AROMATICS

pKa H2O (DMSO)

Substrate

SULFIDES

X

H CH3 Ph COPh CONR2 CO2Et CN OPh N+Me3 SPh SO2Ph

pKa H2O (DMSO)

Substrate

Chem 206

(14.3)

D. H. Ripin, D. A. Evans

pKa's of CH bonds at Heteroatom Substituted Carbon & References

pKa H2O (DMSO)

Substrate

ETHERS CH3OPh MeOCH2SO2Ph

(30.7)

PhOCH2SO2Ph

(27.9)

PhOCH2CN

(28.1)

O

(22.85) Ph

NITRO

P+H4

-14

RNO2

MeP+H3

2.7

Et3P+H Ph3P+CH3 Ph3P+i-Pr Ph3P+CH2COPh

9.1 (22.4) (21.2) (6.2)

R= CH3 CH2Me CHMe2 CH2Ph CH2Bn

Ph3P+CH2CN

(7.0)

PHOSPONATES & PHOSPHINE OXIDES

SELENIDES (18.6) Ph

PhSeCHPh2

(27.5)

(PhSe)2CH2

(31.3)

PhSeCH2Ph

(31.0)

PhSeCH=CHCH2SePh

(27.2)

X=

O Ph2P

AMMONIUM

X= Me3N+CH2X X= CN SO2Ph COPh CO2Et CONEt2

(20.0) (24.9)

(17.2) (16.7) (16.9) (12.2) (16.2) (11.8) (7.1) (7.7)

O2N

X

Ph

(27.6)

CN CO2Et

(16.4)

Cl SiMe3

n=

(18.6) (26.2) (28.8)

3

(26.9)

4

(17.8)

5 6

(16.0) (17.9) (15.8)

7

X

SPh CN

(24.9) (16.9)

N Ph

PHOSPHINES Ph2PCH2PPh2

(29.9)

Ph2PCH2SO2Ph

(20.2)

Ph

JACS 97, 7007 (1975) JACS 97, 7160 (1975) JACS 97, 442 (1975) JACS 105, 6188 (1983) JOC 41, 1883 (1976) JOC 41, 1885 (1976) JOC 41, 2786 (1976) JOC 41, 2508 (1976) JOC 42, 1817 (1977) JOC 42, 321 (1977) JOC 42, 326 (1977) JOC 43, 3113 (1978) JOC 43, 3095 (1978) JOC 43, 1764 (1978) JOC 45, 3325 (1980) JOC 45, 3305 (1980) JOC 45, 3884 (1980) JOC 46, 4327 (1981) JOC 46, 632 (1981) JOC 47, 3224 (1982) JOC 47, 2504 (1982) Acc. Chem. Res. 21, 456 (1988) Unpublished results of F. Bordwell Water:

IMINES

(20.6) (19.4) (14.6)

≈10

n

(EtO)2P

REFERENCES DMSO:

CH2SPh CH2SO2Ph CH2COPh

O

O PhSe

pKa H2O (DMSO)

Substrate

PHOSPHONIUM (49)

MeO

pKa H2O (DMSO)

Substrate

Chem 206

(24.3)

Ph

Oxime ethers are ~ 10 pka units less acidic than their ketone counterparts Streitwieser, JOC 1991, 56, 1989

Advanced Org. Chem., 3rd Ed. J. March (1985) Unpublished results of W. P. Jencks THF: JACS 110, 5705 (1988) See cited website below for additional data

*Values 14 for water and >35 for DMSO were extrapolated using various methods. For a comprehensive compilation of Brodwell pKa data see: http://www.chem.wisc.edu/areas/reich/pkatable/index.htm pKa Table.5 11/4/05 1:45 PM

DMSO Acidities of Common Heterocycles Bordwell, ACR, 1988, 21, 456 Bordwell http://www.chem.wisc.edu/areas/reich/pkatable/index.htm N

N N N H

N H

23.0

19.8

18.6

16.4

N H

20.8

24.0

N H

13.9

11.9

18.0

O

O O

N H

N H

N H

O O

N

N

N H

N H

N

N

O

O

N H

N H

15.0

12.1

O

N H

26.4

O

24.0 Me

O

S S

H

H N H

S N H

N H

N

Me

S Me

N+ Me

Me

N

N

H N+

H Me

N+

Me Me

13.3

Pka Table.6.cdx 11/4/05 1:45 PM

14.8

11.8

29.4

16.5

18.4

Me

24

Me