The radical chain addition of difluoramine to olefins

Journal of Fluorine Chemistry, 48 (1990)

309-3

THE

OF DIFLUORAMINE

RADICAL

WILLIAM

H.

Rohm and Alabama

CHAIN

ADDITION

17

309

TO

OLEFINS

GRAHAM*

Haas

35807

Company, (U.S.A

Redstone

Research

Laboratorles,

Huntsville,

)

SUMMARY

The chain

additton

mechanism

octane,

of difluoramlne, to give

Z-dlfluoraminonorbornane,

difluoramlnocyclopentane 1 -octene, radical and

HNF2,

catalysts

prepared

cyclohexene

used

included

methylethylketone

takes

adducts

place

Thus,

difluoraminocyclohexane

were

norbornene,

to oleflns

mono-dlfluoramino

and

by the

tetrafluorohydrazine

a radical

and

reaction

cyclopentene,

by

l-dlfluoramino-

of drfluoramine respectively.

(N2F4),

with Free

benzoyl

peroxlde

peroxide

INTRODUCTION

The and

successful

Kennedy,

of difluoramino thermal

synthesis

reported

in 1958[1],

derivatives.

dissociation

of

of tetrafluorohydrazine,

Thus,

F2NNF2,

opened the

was first

the

F2NNF2,

new field

dlfluoramino added

by

of organic

radical,

to oleflns

by

Colburn chemistry

formed

by

Petry

and

Freeman [2].

*Present

Address:

Alabama

35815-1506

0022-l 139/90/$3

50

Thiokol

Corporation,

P.0

Box 400006,

Huntsville,

(U.S.A.). 0 Elsevier Sequola/Prmted

m The Netherlands

310

A F2N-NF2

-

2 .NF2 TF2

.NF2

R

R-C-CH2NF2

‘C=CH2 R’

-

Bumgardner

extended

k

excitation

and

obtained

fluoronitrene

The the

2

.F VCH.

which

__)

*NF

-

3

reacts

expected

from

Markownikoff

ion.

R CNF 3 2

RESULTS

by

HNF2,

carbonium

here

the

carbon-carbon

AND

Previous

from

the

to hydrocarbon

radical.

carbonium

acidic

ions was

The

conditions

addition gives

addition[S]

shown

to give

of HNF2

to

f-butyldifluoramine,

to the

more

stable,

0

H

addition

of difluoramine

under

free-radical

conditions

bond.

DISCUSSION additions

by

the

to the

of difluoramine

to olefins

ion mechanisms more

the addition

addition

+

double

by carbonium

difluoramine

The

saturated

dissociates

a difluoramino

derivative[4].

under

We report

represents

even

photolytlc

CH3NF2

HNF2

terminal

from

by

+ *F

difluoramino

R3C @ _

the

radical

radical

hydrogen

with

as isobutylene

product

substituted

we report

derivatives

abstracts

of difluoramine,

such

proceed

difluoramino

.NF2

alkylation

to the

of the

difluoramino

which

radical

corresponding

olefins the

*

hu

activated

fluorine

an alkyl

--t.NF

.NF2

CH4

and

reactivity

difluroamino

The

hydrocarbons[3].

to form

the

substituted

olefin,

have

or more

of difluoramine

terminal

an example

and

to olefins 1-octene,

of anti-Markownikoff

have

been

resulted

stable

postulated

in the

carbonium

under to yield

addition

free

to

alkylation ion.

radical

of

Here

conditions;

1-difluoramrnooctane of difluoramine

to the

carbon. free

radical

tetrafluorohydrazine,

reagents benzoyl

investigated peroxide,

to initiate

the

methylethylketone

azo-bis-isobutyronitrile.

Successful

addition

of these

except

azo-bis-isobutyronitrile.

radical

initiators

the

of HNF2

reaction peroxide,

was obtained The

included and with most

all

311 successful The

reactions

CH2CI2 N2F4 at

conditions

appeared

were

carried

in a Fisher-Porter were

condensed

by

using

be made

the

gas

N2F4

of the

amount

dlfluoramino were

volatile taking

was

of N2F4

peroxlde

solution

phase

of the

olefin

vessel.

The

into

evacuated

the

as an Inltlator,

was obtained the

at about

reactlon

used

olefln

adducts

obtained.

starting

yield

of the

spectra,

analyses.

of 1-octene, The

materials

up in CH2CI2,

Characterization infrared

pressure

benzoyl

in CC14 or HNF2

reactlon the

mono-NF2

and vessel

vtcinal

as a byproduct;

of the

105’C.

however,

product

could

to predominate.

cyclopentene

H20,

in a dilute

When adduct

a limited

The

excess

out glass

from

low temperature.

bis-difluoramino

to be with

products such

drying,

products

was

“F

TABLE

1

Nuclear

Magnetic

and

‘H

NMR

Resonance

for

Chemical Structure

“F

CH3(CH2)6CH2NFZ

-55.8(t)

based

are

on the and

“F C,

o-

under ‘H

N,

vacuum.

NMR

and

In Table

of the

with

spectra,

F elemental 1.

Adducts

6

Coupling

3.42

(t,t)

2.43

(t,t)

‘HF

3.25

(t)

Constants,

= 30,

‘FAFB JHH

JHH

= 562,

Hz

= 7

JHF

= 28

= 6

= 24

‘HF

-51.8(d)

NF2

removal

a ‘H,

-41.9(d)

NF2

and H,

and

washing

of the CH2Cl2

(AB,d)

NF2

after

N2F4,

summartzed

Shift

-47.75 -33.75

cyclohexene

Isolated and

Dlfluoramine

, $I

-55.75, -69.85,

D

removal

(GC),

data

Data

were

as HNF2

and

gas chromatography

The

norbornene,

= 32

‘HF

19 F values, 0 are observed downfield relative to internal aThe negative CFCI . the positive 1~ values are 6 and observed downfield relative to The spectral shapes abbreviated as follows: t, triplet; t,t, Si(Cd3) triplet oP triplets; AB, typical AB quartet characteristic of -NF2 adjacent to an asymetric carbon atom; d, doublet.

The

mechanism

IS postulated of the

reaction

of HNF2

to be a typical closely

addition radical

approximate

to olefins chain

those

under

process.

free

radical

In fact,

of the classlcal

radical

the

conditions energetics

chain

addition

312 of HBr and

Thus,

to olefins(b].

hydrogen R.

transfer

(from

peroxide)

+ HNF2

CH3(CH2)5CH=CH2

close

of the

correlation

step,

C-N

In the The

are

energetlcs

reactions N-H

bond

initiator, steps

is

the

reaction The

with

Addition

consists

actual than

thus

bond

the

simply

dlfluoramino

radical

(87

kcal/mole)

C-H the

dlssociatlon

the

addition

(98 overall

for

energetics

HNF2 of the

energy

value

87 kcal/mole

of N2F4 was used

of the

becomes

H-Br made,

92 kcal/mole

nearer

addition broken

kcal/mole

The

a

bonds

energies[7] -12

reveals

in the

the

and

by

dissociation

then

formed

bonds

addition.

the

reactions

and

bond

favorable

and

from

Transfer

HBr

bonds

the

above

lower

tables

and

kcal/mole)

HBr

since

competitlon

another

Initiation

kcal/mole),

and

the

the

probably

radical

of the

(92

are

for

HNF2

(65

N-H

Using

closer

energy NF2

addition

*NF2

the

kcal/mole)

reactions

bond

only.

reacting

step,

In HNF2

When the

for

C-Br

(60

kcal/mole

may be even

in standard HBr.

two

of an initiatron,

CH3(CH2)5CH2CH2NF2

energies

and

identical.

-16

consists

+

HNF2--+

the

C=C

of the and

-+RH

energies

transfer

broken,

kcal/mole),

addition

bond

kcal/mole)

hydrogen

bonds

+

between

(66

reactlon

*NF2-+CH3(CH2)SCHCH2NF2

+

CH3(CH2)SCHCH2NF2 Comparison

the

step:

and

one between or abstracting

avallable value

as the

hydrogen

the

two

of the

of

radmal

transfer

addition-radical

a hydrogen

from

HNF2: TF2

*NF2 b

I CH3(CH2)

CH3(CH2)

5CHCH2NF2

SCHCH2NF2 CH3(CH2)5CH2CH2NF2

This

explains

yields

of the Several

the

facile

HNF2

olefin

limitations

and

ca +

necessity

Markownrkoff

temperature

I

the

HNF2

of keeping adducts

of the

are

the

105T

were

took

no anti-Markownikoff

(BzO12

ratio

small

if good

to be realized.

addition

addition[4]

N2F4/NHF2

place

product

NF2

NF2

identified.

With

irreversibly was formed:

at

dihydropyrane room

313 Furthermore,

no radical

a-methylstyrene; the

reactton

the

olefin-N2F4

instead

intermediate

hydrogen

chain

radical,

from

This

of achieving

a radical

chain

to ethylene;

in addition

radical

In the

transfer

only

IS reminiscent

reaction

between

lsobutylene

increasing

product

acted

HCI

of the and

the

actlvatlon

propylene

for

a

relative

for

reactivity

energy

Apparently,

to abstract

as an inhibltor

oleflns

the

reported

here

2-difluoraminonorbornane.

reactions

of the

asslgned

the

This not

was formed.

with

as compared the

ethylene

of the the

difficulty

Intermediate

hydrogen

step.

The is the

adduct

is too stable

behavior

more substituted

is reduced,

was obtained

&(CH3)CH2NF2,

HNF2.

reaction[8].

of HNF2

2-norbornyl

reaction

is useful

prepared IS

the

as a means

by other

a relatively

with

radical

2-dlfluoraminonorbornane

IS

mono-NF2

Furthermore,

radical

is possible

previous

of preparing

methods.

facile

stereoisomerlsm

on analogy

radical [9],

configuratlon.

readily

which

Based

w

dlfluoramlne

for

chain

compounds

it illustrates

transfer

that

agent.

EXPERIMENTAL

General

Caution:

Mixtures

compounds

and

compounds

should

of difluoramine

oxygen

are

only

highly

or tetrafiuorohydrazine All

explosive.

be conducted

with

with

reactions

adequate

with

shielding

organic

these

and

precautions. NMR

(“F)

V-3000-B, obtained

high

on a Varian,

measured chloride

spectra

on a Perkln plates.

spectra

are

relative

to internal

respectively.

were

resolution

The

reported

obtained

spectrometer

Model

60,

Elmer

lnfracord

chemical

and

a Varian

using

shift

Infrared

double-beam @ and

d values

(negative

downfield

Associates,

Model

a 40 Hz probe;‘H

60 Hz probe.

as ppm upfield CFC13

with

values

relative

spectra

spectra

were

instrument

using

of the

and

“F

were

are observed

to tetramethylsilane,

sodium ‘H

NMR

downfleld)

314 ReactIon

I-Octene

of

A solution for

3 hours

mole)

with

of 0.56

at IOO’C

In a glass the

150 ml;

the

pressure

(0.0004

mole),

removed

under

H20,

Both

a ratio 4:l.

vessel

vacuum,

liquid

over

the CaC12,

ratio

typical

proton.

and

e-36.75

584

Hz).

column

(JHF The

= 28 Hz)

(J HF = 30 Hz);

Reaction

C,

for H,

N2F4.

After

150 ml with

66% HNF2 were

H20

extracted on a rotary

mole),

under

with

mole)

evaporator

of triplets

=

centered

= 7 Hz.

and

N,

norbornene mole)

The

71 9 u.

8.48;

F,

23 00.

and

to leave

in 5 ml CC14 was heated and Into

of 400 mm.

After

of Tetrafluorohvdrazine

HNF2

expanded

26% N2F4

vacuum

CH2CI2.

(JFAFB

at +-55.8

JHH

at 11.5

with

= 20 Hz)

on an SF-96

triplet

In Presence

were

a pressure

(0.0023

removed

Difluoramlne

contents

-22.25

10.37;

(JHF

23.4.

200 ml (0.009

the

05 and

a triplet

H,

carbon

separation

= 30 Hz,

typical

and a doublet

35

JHF

F,

had the

at q-39

-CH2NF2

Indicated

of approximately

= 24 Hz,

contalned

58 15,

8.45;

g (0.005

with

cooling

volatlles and

with

after

NF absorption

strong

N,

at q-54

washed

g of a liquid

areas

to an assymetric

had a typical

C8H17NF2.C,

of 0.47

2 hours

approximately

wings

spectrum

10.3;

of Norbornene

for

the

JHF

centered

was trapped

product

featured

58 6;

A solution

attached were

and

1.19

probe

adduct

at q-57.1,

were

in CH2CI2,

CHNF2CH2NF2

peaks

peak

proton

NMR

10% N2F4

volatiles

yield:

lgF

CH3(CH2)5

to tetramethylsllane),

Calcd

at 93°C

Indicated

the

spectrum

Anal. Found:

The

(relative

infrared

GC

and

(0.006

to room

indicated

up

stripped;

HNF2

of approximately

The

mole)

was taken

and

group

central

smaller

at 121OC.

at 6 3.42

removed

of an NF2 The

residue

centered

and

cooling

to a volume

to HNF2/1-octene

adduct,

pattern

mole)

After

mass spectrum

GC peaks

adduct

In 10 ml of CC14 was heated

(0.006

(0.003

filtered,

of the

of Tetrafluorohvdrazine

vessel.

was opened

80% HNF2

triplet

pattern

a single

of N2F4

pressure

10% CC14 and

the

1-octene

was 435 mm and the

N2F4/1-octene “F

In Presence

mole)

a mixture

of N2F4/1-octene The

-CH2NF2 AB

with

pressure

dried

residue.

g (0.0050

Fisher-Porter

temperature

with

Difluoramrne

The

(0.001

the

drying

liquid over

a residue

50 ml (0.002 a volume mass

mole)

spectrum

and

residue CaC12 of 0.60

mole)

of

8% CC14. poured

The

into

the

CH2Cl2

g.

The

“F

was NMR

315

spectrum

of the

products

with

AB

residue

quartets.

of the

products

with

the

more

volatile

volatile

peak

was trapped

central

peaks

at q-55.75

= 562 HZ, triplets

JHF

spectrum

Found:

C,

The

56.7;

H,

“F

with

N2F4

and

wings

Reaction

for

had

‘H

NF absorption

C7H11NF2:C, 7.55;

spectrum

N,

9.98;

asslgned

F,

AB

pattern

at (p-73.3

-40

3 (JFAF8

and

of Norbornene

2 hours

benzoyl of HNF2 residue ratio

at 108’C

peroxide. remained. only

had

benzoyl

foot

for

norbornene mole)

p.

25 82.

cooling

and

expansion

after

washlng

of norbornene

at e-58.9

JHF

and

of Benzoyl

and

0.36

Peroxide

1.0

mole)

0.00025

g.

dlfluoraminonorbornane

was heated

g (0.0015

approximately was

-54.7

= 24 Hz)

in 15 ml CH2Cl2

HNF2

residue

-80X

of 0.82

3 hours

and

stripped used

DOW 11 silicone

trapped

out.

24 Hz);

the

The ‘H

Dtfluoramine

g (0.01

with

was washed

trap

with

mole)

The

mole

GC of the

peaks

with

to a residue

In the

the

column

at 65%

spectrum

spectrum had

up

a poorly

of HNF2

The

Indicated

was

a doublet defined

and

0.24

area

Peroxide

centered triplet

was

over

CaCl2,

Identified

in

through

a 5

peak

which

was

at e-41.9

(JHF

separation

a single

mole)

recovered.

dried

product GC

was heated

g (0.001

were

in CH2Cl2,

g (some

stripping).

of Benzovl

In 10 ml CH2Cl2

HNF2

moles

taken of 0.62

during

“F

mole)

0.0016

H20,

111 Presence

cyclohexene

224 ml (0.01

Approximately

peroxide.

residue

filtered the

12.2 F,

adduct

peaks

in Presence

The

of Cvclohexene

A solution 106K

The

central

After

and

and 9.52;

of

infrared

of 15:85.

Reaction

at

N,

triplet

The

11.75,

more the

75 (JFAFB

an apparent

7.54;

= 576 Hz,

250 ml (0.011

norbornene

-33

This with

25.10.

with Difluoramine

with

and

= 6 Hz).

10 75, H,

with

A solution of 0.94 g (0.01 mole) for

JHH

to the bis-dtfluoramino

was a doublet

pattern

at +-69.84

contained

at

57.13;

AB

two

two principal

of 84:16

doublet

and wings

of mainly

revealed

in a ratio

an “F

spectrum

a mixture

products

present

(J HF = 28 Hz,

strong

Calcd

and -47.75

the

at d 3.42

featured

Anal.

and

indicated

GC of the

being

out

= 28 Hz);

centered

products

The

major

centered

at 3.25

= (J =

316

The

24 Hz). 10 35,

10 9, Anal.

Found:

C,

Reaction

infrared and

for

52.9;

H,

and

8.59;

N,

was

mole)

recovered

stripped

product

peak

Anal. C,

F,

NF absorption

with

peaks

at

a “F

Calcd

for

49.43;

H,

F,

27.95.

Benzovl

250 ml HNF2

Peroxide

was heated

(0.011

0.0008

mass spectral

analysis.

The

dried

CaCl2,

0 63 g of

at ~-51.8

(JHF at

49.58;

11.22;

column

residue

= 32 HZ)

7 49;

N,

filtered

a principal

The

11.70

liquid

GC

afforded

10 85 and H,

F,

over

mole)

mole of

up In CH2CI2, to yield

C,

of

Approximately

NF absorption

N,

10.31;

in 10 ml CH2Cl2

with

DOW 11 sIllcone

C5HgNF2:

N,

In Presence

bottle

by

doublet

7.64;

8.74;

29 7.

peroxide

evaporator

strong

H,

cyclopentene

taken

on a 5 foot

featured

Found:

H20,

on a rotary

53.00,

pressure

benzoyl

with

at 60°C

spectrum

strong

Difluoramine

as lndlcated

was washed

separation

C,

10.7;

with

in a glass

g (0.001

residue

NF2:

of 0 68 g (0 01 mole)

at 105-C

0.24

HNF2

C6Hll

of CvcloDentene

3 hours

featured

11.8~

Calcd

A solution

and

spectrum

Infrared

~_r.

11.57;

F,

31.37.

31.0.

ACKNOWLEDGEMENT

The

author

wishes

Arsenal,

Alabama,

and

Kirt

Mr.

to thank

Contract

Keller,

No.

the

U.S.

Army

Missile

DAAHOl-67-C-065,

who provided

technical

for

Command, support

Redstone

of this

work

assistance.

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1

C.

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(a)

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C.

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B. R. R.

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J.

C.

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J.

L

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4

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H.

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W.

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J.

J

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Am.

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C.

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