Organophosphorus compounds, part 146 imidovanadium(V) complexes as reaction partners for kinetically stabilized phosphaalkynes. Synthesis and reactivity of 3-Aza-1,2,4,6-tetraphospha-quadricyclanes

Organophosphorus Compounds, Part 146*

Imidovanadium(V) Complexes as Reaction Partners for Kinetically

Stabilized Phosphaalkynes. Synthesis and Reactivity of

3-Aza-l,2,4,6-tetraphospha-quadricyclanes

Christoph Peters, Frank Tabellion, Anja Nachbauer, Uwe Fischbeck, Fritz Preuss,

and M anfred Regitz

Fachbereich Chemie der Universität Kaiserslautern, Erwin-Schrödinger-Straße,

D-67663 Kaiserslautern

Reprint requests to Prof. Dr. M. Regitz. E-mail: regitz@rhrk.uni-kl.de.

Prof. Dr. F. Preuss. E-mail: fpreuss@rhrk.uni-kl.de

Z. Naturforsch. 56b, 951-962 (2001); received April 11, 2001

Cyclooligomerization of Phosphaalkynes, Imidovanadium(V) Complexes,

3-Aza-l,2,4,6-tetraphospha-quadricyclanes

The Lewis base adducts of imidovanadium(V) compounds 5a,b undergo chemoselective

cyclooligomerization reactions with the kinetically stabilized phosphaalkynes 4a-e to furnish

the azatetraphosphaquadricyclanes 6a-f with incorporation of the imido fragment. The reac-

tivity of this novel class of heteropolycyclic compounds has been examined exemplarily for

compound 6a. Complexation of one and two phosphorus atoms was achieved by reaction

with nonacarbonyldiiron or the tungsten pentacarbonyl-THF complex resulting in the forma-

tion of the transition metal compounds 17-20. Reactions of 6a with the sulfonyl azides 21a-

c furnished the Staudinger products 22a-c. The reaction of 6a with two equivalents of tosyl

azide gave a surprising result. No double complexation leading to a symmetrical product was

achieved, and compound 23 was obtained instead in which the two phosphorus atoms of one

diphosphirane ring are functionalized. Oxidative cleavage of a P/P bond in 6a to furnish

product 24 is observed in the reaction of 6a with the Lewis base-free imidovanadium(V)

species 15a.

Introduction

M ajor breakthroughs in this development in-

clude the syntheses of the tetraphosphacubane

1

Cage compounds, some of which have highly

symmetrical skeletons, have always been of great

interest to chemists. Their often tedious, multi-

stage syntheses have presented a challenge to ex-

perim ental techniques and the unusual bonding

relationships have generated new impulses for

theoretical considerations.

Thus, it is not surprising that the construction of

phosphorus-carbon cage compounds has devel-

oped into an im portant field in the chemistry of

kinetically stabilized phosphaalkynes. In contrast

to their all-carbon analogues, however, access to

the phosphorus-carbon cage systems has only be-

come possible in the past ten years with the phos-

phaalkynes being indispensable starting com-

pounds.

[

1

], the tetraphosphabishom oprism ane

2

[2

], and

the hexaphosphapentaprism ane 3 [3] (Scheme 1).

The cubane 1 was of particular interest on account

of its high symmetry and its at first inexplicable

spectral properties. Accordingly, the rem arkably

stable cubane

1

has, on the one hand, been the

subject of numerous theoretical bonding studies

[4-6] and, on the other hand, the starting point

for many functionalization reactions at the phos-

phorus atoms [7-9]. A lthough the first syntheses

of the phosphaalkyne tetram ers

1

and

2

were

based on the thermolysis of the fe/t-butylphos-

phaalkyne 4a, many novel synthetic strategies

have since been developed for the specific con-

struction of polycyclic phosphorus-carbon systems.

These now provide selective and high-yield access

to the cage compounds 1 and 2. The synthetic prin-

ciples employed include transition metal- (—>

1

[10,11]), base- (—»• 2 [12]), and Lewis acid-medi-

ated processes (—*■3 [3]).

* Part 145: S. G. Ruf, U. Bergsträsser, M. Regitz, Eur. J.

Org. Chem. 2000, 2219.

N

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952

C. Peters et al. • Organophosphorus Compounds, Part 146

4 P = C — R

4

+

f-BuN=VCI3 DME

5a

In this context we posed the question of whether

and how the kinetically stabilized phosphaalkynes

would react with imidovanadium(V) compounds

which possess Lewis acid character. We expected

that the enorm ous cyclooligomerization potential

of the phosphaalkynes would result in the form a-

tion of oligomeric phosphorus-carbon compounds.

toluene, -78 °C—»-25 °C

- R —C = C —R

side reaction

-

"VCI3-DME"

not observed

for 4a, c

f-Bu

\

N3

V.

lu

^

4

I-Bu P r y Ps t Bu

Bx V | - p\

m

$$

^

t-Bu

4, 6, 7

1

Me

Scheme 1

f-Bu

f-Pen

ever

In the present article we describe the selective

synthesis of the 3-aza-l,2,4,6-tetraphosphaquadri-

Scheme 2

cyclanes

6

, form ed by cocyclooligomerization of

the phosphaalkynes 4 proceeding with concomi-

tant incorporation of the imido fragment of the

vanadium compound and cleavage of two RC

fragments (—» alkynes).

at d = 1.53 as a triplet with a 4JHP coupling of

0.9 Hz. The 1 3 C[ H} NM R spectrum contains the

signals for the r-butyl groups as well as a multiplet

at d - 30.3 for the skeletal carbon atoms C-5 and

C-l which cannot be distinguished.

1

Results and Discussion

The structure proposed for 6a is in harmony

with these NMR data and was confirmed by single

crystal X-ray crystallography [13].

Formation o f azatetraphosphaquadricyclanes

The reactions of the phosphaalkynes 4a-e with

the imidovanadium(V) com pound 5a in a molar

ratio of 4:1 furnished the yellow azatetraphos-

phaquadricyclanes 6a-e rather selectively in yields

of 47-76% [13]. The corresponding 1,3,5-triphos-

phabenzenes [14] 7b,d,e (1 -3 % ) were form ed as

by-products only in the reactions of the phos-

phaalkynes 4b, 4d, and 4e (Scheme 2).

4 P = C— f-Bu (4a)

f-B uN =VX, DME --------------------------------------

toluene, -78°C—► 25°C

►

6a

X = Cl (8a) 3r (8b)

Scheme 3

In order to examine the dependence of the reac-

tion on the oxidation state of the imidovanadium

compound, the phosphaalkyne 4a was allowed to

react with the imidovanadium(IV) complexes 8a

and 8b [15] (Scheme 3). In analogy to the reaction

with the vanadium(V) compound 5a selective for-

mation of the cage compound 6a was observed.

Variation of the substituent at nitrogen in the

imidovanadium(V) complex also enabled the sub-

stitution pattern of the tetracyclic product to be

changed. Thus, reaction of the iV-l-adamantyl sub-

stituted vanadium compound 5b with four equiva-

lents of 4a furnished the azatetraphosphaquadri-

cyclane 6f together with a small am ount of the

triphosphabenzene 7a as a by-product (Scheme 4).

The structure elucidation of compounds

6

from

the NM R data is discussed for the example of pro-

duct 6a: The four phosphorus atoms of the tetracy-

clic system give rise to the signals of an A A 'X X '

spin system centered at d = -7 .4 (P2, P4) and -

123.0 (PI, P ). Although the signals in the A part

6

of the spectrum are strongly broadened on ac-

count of the proximity of the 14N atom (I = 1),

coupling constants in the range from

2

. 1 to 161.1

Hz can be derived from the X part. The *H NM R

spectrum supports this interpretation; the two t-

butyl groups at C-5 and C-l give a doublet signal

at d - 1.00 with a 4/ H P coupling of 1.2 Hz, while

the signal of the r-butyl group at nitrogen appears

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C. Peters et al. • Organophosphorus Compounds, Part 146

1-Ad

pounds 4a and 5a are allowed to react in a molar

\

ratio of

2

:1 , an inseparable mixture of 6a and

the previously unknown 1,2,5-azadiphosphole

11a, characterized unambiguously by NM R

spectroscopy, is obtained. Recently Nixon and co-

workers [16] have described the synthesis and

crystal structure of the 1,2,5-azadiphosphole (11a)

1-AdN=VCI3 DME (5b)

ß

toluene, -78°C—

25°C

4P = C-'Bu

4a

- 'Bu - C= C -'Bu

- "VCU- DME"

6 f

t-Bu

complex

[Ir(?7 5 -Cp*)(?7 4 -{'BuCPNtBuPCtBu})]

Scheme 4

starting from [IrCp*(NfBu] on treatm ent with an

excess of 4a. A ttem pts to displace 11a from irid-

ium have proved unsuccessful. Convincing evi-

dence that 11a is an interm ediate on the way to

the quadricyclane is provided by the addition of

further phosphaalkyne 4a to a mixture of 6a and

11a. In this case 11a reacts as expected to give

6a which at the same time excludes the further

participation of transition metal fragments in the

following reaction steps. NM R spectroscopic m on-

itoring reveals that the form ation of 6a proceeds

by way of the interm ediate 12a (Fig. 1) which,

however, cannot be isolated on account of its lim-

ited stability. These experim ental observations al-

low the following mechanism for the formation of

the quadricyclanes to be proposed (Scheme 5).

The unstable four-membered metallacyclic spe-

cies 9 is formed in a [2+2] cycloaddition between

the DM E adduct 5 and the phosphaalkyne 4. A fter

insertion of a second equivalent of 4 into the V/N

bond a formal ring expansion to afford the six-

mem bered metallacyclic species 10 occurs. The

subsequent reductive elimination of the transition

metal fragment, detected in the residue as

A part from the signals of the different substituents

at nitrogen ( -adamantyl in place of /-butyl) the

f were in good agreement with

1

NM R data of

6

those of 6a.

A plausible mechanism for the formation of the

azatetraphosphaquadricyclanes can be proposed

6

because 31P and 51V NMR spectroscopic m onitor-

ing of the reaction of 4a with 5a (no by-product

7a!) reveals the presence of the three interm edi-

ates 9, 11, and 12. When the DM E adduct 5a is

allowed to react with only one equivalent of 4a the

specific form ation of the metallacyclic species 9a

is observed by NMR spectroscopy (Table 1);

however, its isolation after removal of the solvent

is not possible (see below). When the com-

Table 1. Characteristic 51V and 31P NMR data of 1,2,4-

azaphosphavanada(V)cyclobutene 9* and 16a.

(3(51V)

[ppm]

Compound

<K31P) [ppm]

Wm

[Hz]

367

460

-73.0

-68.4

DME complex (9a)*

PMe^ complex*

+307

+308

VC1 *1.5 DM E, furnishes the 1,2,5-azadiphos-

3

+30.9 (coord. PMe-j)

-72.9

+36.3 (coord. PPh,)

-73.0

phole 11. In the following reaction step 11 un-

dergoes a [4+2] cycloaddition with a third equiva-

lent of 4 to give the azatriphosphanorbornadiene

12 which dissociates in a retro-D iels-A lder reac-

tion to liberate the dialkylacetylene and the azatri-

phosphole 13. In the case of the 1-adamantylphos-

phaalkyne 4c bis(l-adam antyl)acetylene can be

isolated and identified by comparison with litera-

ture data [17]. The final steps of the sequence com-

prise a further [4+2] cycloaddition with a fourth

equivalent of the phosphaalkyne. The resultant

azatetraphosphanorbornadiene 14 then undergoes

stabilization by way of an intramolecular, head-to-

tail cycloaddition of the two phosphaalkene units

PPh^ complex*

16a [14]

+306

+310

320

209

* Unstable intermediate.

'Bu

106.1 ppm, d, JPP= 34.9 Hz

l\ ' '

P

<

_jX

(

/

P

—1------- 314.7 ppm, d,

Jpp = 226.7 Hz

135.7 ppm, dd, 'jPP= 226.7,2JPP= 34.9 Hz

[

1

,

2

] to form the tetracyclic system

Equim olar amounts of phosphaalkyne 4a and

the Lewis base-free imidovanadium(V) trichloride

6

.

Fig. 1. 3 1 P{'H}NMR data (C D6) of the unstable azatri-

6

phosphanorbornadiene 12a, obtained by direct NMR

spectral monitoring of the reaction of 4a with 5a.

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C. Peters et al. ■Organophosphorus Compounds, Part 146

R'

,BuN = VC13 ■DME + P = C -‘Bu

lBuN = VC13 + P = C -‘Bu

/

==r. — r (A \

P

C

-------

N

P = C — R (4)

V/N-Insertion

5a

4a

15a

4a

R N=VCI, DME

[2+2]

------ VCI, DME

/

toluene

-78°C -» 25°C

toluene

-78°C -> 25°C

\

reductive

R.

_.p

C = P

Elimination

/

\

DM ECI3V

N-----R

N— R-

‘Bu

- 'VCI3 DME"

\

/

P — N

+DME

P — N

C = P

Cl

/

/ C

cBu

VC13 • DME

toluene

R

10

Cl

-78°C ^ 25 °C

‘Bu

Cl

R-

\

9a

16a

3 P = C -‘Bu

V/N-insertion

3 P = C-*Bu

V/C-insertion

P = C — R (4)

[4+2]

« y j 1

- R—C = C —R

12

R'

\

Scheme

6

\

P = C —R (4)

-----R ------------------------—

[4+2]

N

tion of 4a, while in the absence of DM E triphos-

phabenzene 7a is formed (Scheme ). The specific

'yr

■

'p

/

6

P '

formation of 6a or 7a via 9a or 16a is observed

only for r-butyl as a substituent of the imidovanad-

ium(V) compound and the phosphaalkyne;

changes in the alkyl group afford triphosphaben-

zene 7 and quadricyclane 6 as by-products indicat-

ing that both l,2,4-azaphosphavanada(V)cyclobu-

tene rings 9 and 16 can react with phosphaalkyne

by V/N- and V/C-insertion at a time in one way

13

14

[2+2]-intramolecular

selectively. Starting from fBuN=VCl

3

-PR

3

(R =

6

R

Me, Ph) [18] and one equivalent of 4a, the corre-

sponding metallacycles 9 (Table 1) are formed,

which are unstable and produce 1,2,5-azadiphos-

phole 11a and quadricyclane 6a by decomposition.

Scheme 5

15a furnish the stable and isolable 1,2,4-azaphos-

phavanada(V)cyclobutene 16a; on reaction with

an excess of 4a the 1,3,5-triphosphabenzene 7a is

formed by a catalytic process [14], The good

agreement of the 31P and 51V NM R data for 16a

and 9a (Table 1) supports the proposed four-

Studies on the Reactivity of the Azatetra-

phosphaquadricyclane 6a

In addition to the synthesis of the title com-

membered ring structure of 9a which unlike 16a pounds we were also interested in their reactivity.

possess four V o 3-

6

undergoes decomposition (no identifiable pro- The tetracyclic compounds

ducts) and can be merely detected as an unstable

intermediate by NM R spectroscopy. When 16a is

phosphorus atoms with a predisposition for func-

tionalization reactions. Thus, we investigated the

allowed to react with one equivalent of DM E, 9a ability of the polycyclic compound 6a, which is

is formed furnishing the quadricyclane 6a on addi- preparatively the most easily accessible, to func-

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C. Peters et al. • Organophosphorus Compounds, Part 146

955

tion as a phosphane ligand in transition metal

complexes.

complexed phosphorus atom P-l in compound 18

at (5 = -104.1 exhibits typical tungsten satellite

lines with a Vpw coupling of 222.3 Hz. This signal

appears as a double pseudotriplet as a result of a

Complexation o f 6a with diiron nonacarbonyl and

the tungsten pentacarbonyl-THF complex

1

yPP coupling of 151.7 Hz and two equally sized

2/ PP couplings of Hz. As expected, the !H

NM R spectra contain three signals each for the t-

butyl groups of compounds 17 and 18 with charac-

~

6

The reactions of the azatetraphosphaquadri-

cyclane 6a with diiron nonacarbonyl in toluene, or

tungsten pentacarbonyl-TH F complex in tetrahy-

teristic chemical shifts. The 1 3 C{ H} NM R spectra

1

drofuran, in a m olar ratio of

complexes 17 or 18. Although the 3 1 P{

1

: 1 afforded the rj1-

H} NMR

also support the retention of the quadricyclane

structure. W hen the chemical shifts of the carbon

signals of 17 and 18 are com pared with those of

the starting m aterial 6a, it is seen that the skeletal

carbon atoms C-5 and C-7 experience a marked

paramagnetic shift from (3 = 30.3 (6a) to values of

d = 36.5 - 40.0. In addition to the more or less

unchanged positions of the signals for the carbon

atoms of the r-butyl groups, there are also the ex-

pected signal patterns for the carbon atoms of the

carbonyl groups bound to the respective metal.

While the carbonyl ligands of compound 17 give

rise to only one signal at low field (<5 = 217.3), the

carbon atoms of the carbonyl ligands in compound

18 produce separate signals for the axial (<3 =

197.8) and the equatorial (<5 = 196.8) ligands.

1

spectra of the crude reaction mixtures reveal the

presence of the starting m aterial 6a together with

the respective singly and doubly (see below) com-

plexed tetracyclic species, chromatographic work-

up and subsequent crystallization from pentane se-

lectively furnishes the pure complexes 17 or 18

(Scheme 7).

t-Bu

Fe2(CO)9

toluene, 25 °C

-

Fe(CO)5

(0C)4

Two-fold complexation o f 6a

6a

W hen 6a was allowed to react with diiron nona-

carbonyl or, respectively, tungsten pentacarbonyl-

TH F complex in a m olar ratio of 1:2, the doubly

complexed tetracyclic species 19 or 20 were

W(CO)5(thf)

THF, 25 °C

-T H F

formed (Scheme

The 1:2 composition of the products 19 and 20

from one molecule of the quadricyclane a and

8

).

/

(0C )5W

6

two parts of the transition metal fragment is

clearly apparent from elem ental analytical and

mass spectral data. In accord with the symmetrical

Scheme 7

Elem ental analytical and mass spectral data

clearly dem onstrate the formation of the com-

plexes 17 and 18 from one molecule of 6a and a

16-valence electron m etal fragment. In accord

coordination of

tion metal carbonyl fragments, the 3 1 P{

spectra of 19 and 20 reveal splitting patterns anal-

a although the resonances

of 19 and 20 occur at lower field than those of

a. The shift to lower field is larger for the iron-

ing only m inor changes in the chemical shifts in complexed phosphorus atoms. Thus, the signals for

6

a by two of the respective transi-

1

H} NM R

with the unsymmetrical structures of the com- ogous to the signals of

plexes 17 and 18, their 3 1 P{ H} NM R spectra each

contain four signals with the complexation effect-

6

1

6

comparison to the uncomplexed starting material

6a. An exception is the signal of the complexed

phosphorus atom P-l in the iron complex 17 which

experiences a significant shift to low field (d =

-40.7). Furtherm ore, the signal for the tungsten-

the complexed phosphorus atoms P -l/P - 6 are seen

at d = -43.9 (19) and d = -111.9 (20) [compared

with d = -122.7 (

found at d = 19.6 (19) and d -21.7 (20) [compared

with d = -7.1 ( H} NM R spectra of

6

a)] and those for P-2/P-4 are

6

a)]. The 1 3 C[

1

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956

C. Peters et al. • Organophosphorus Compounds, Part 146

RS02N3 (21)

2 Fe2(CO)9

CH2CI2, 25 °C, 2 d

toluene, 25 °C

6a

-N,

—2 Fe(CO)5

p

/

19

t-Bu

RO,S— N

(OC)4Fe

6a

a

b

c

21, 22

R

2 W(CO)5(thf)

Me

p-Tol

p-C 6H4-N H -C (0)C H 3

THF, 25 °C

- 2 THF

Scheme 9

f-Bu

(OC)5W

Scheme

8

The mass spectral data and a correct elem ental

analysis for b clearly dem onstrate the form ation

of the polycyclic species a-c from one equivalent

of the quadricyclane a and one equivalent of the

respective sulfonyl azide a-c with loss of a m ole-

cule of nitrogen. Owing to the form ation of the

m onophosphane imines the 3 1 P[ H} N M R spectra

of compounds a-c in each case reveal four signal

groups indicative of an unsymmetrical structure.

As a result of the deshielding effect of the doubly

bonded nitrogen, the signals of phosphorus atoms

P-l experience a dramatic shift to lower field in

comparison to the corresponding signal of the star-

2

6

19 and 20 also reflect their symmetrical structures.

As expected, the chemical shifts of the skeletal

carbon atoms C-5 and C-l are most affected by

the complexation. In contrast to these low field

shifts for C-5 and C-l of d = 44.5 and d = 41.9,

respectively, for 19 and 20 as com pared to d = 30.3

2

1

2

for a, the signals for the r-butyl groups are practi-

6

cally unchanged.

Although these single and double complex-

ations of a can be realized at room tem perature,

6

ing material a and appear at d = 198.6-203.2. The

6

three- and four-fold complexations have not yet

been achieved.

signals of the phosphorus atom P-2 at d - 130.8-

133.9 are also markedly shifted by ca. 140 ppm to

lower field. The two signal groups in the high field

region at d = -19.6 to -22.2 for P-4 and at d =

-142.7 to -146.7 for P- 6 are suggestive of an in-

tact diphosphirane unit that is not appreciably in-

fluenced by the functionalization. In contrast, the

Simple Staudinger reactions o f

azides a-c

6

a with the sulfonyl

2

1

The Staudinger reaction [19] of phosphanes with

organic azides to produce phosphane imines also

plays a significant role in the chemistry of phos- coupling constants in the functionalized diphos-

phorus-carbon cage compounds. Thus, for exam - phirane unit reveal a characteristic feature, namely

ple, the tetraphosphacubane

doubly functionalized by means of the Staudinger Vpp coupling constants between P-l and P-2 from

reaction [20,21], Thus, it was of interest to examine 161.0 Hz in a to 4.5 - 6.1 Hz in the Staudinger

the behavior of r-butylquadricyclane a under the

conditions of the Staudinger reaction.

Reactions of a with an equim olar am ount of

the sulfonyl azides a-c resulted in the selective

1

has been singly and

the drastic reduction in magnitude of the direct

6

products 22a-c. Besides the typical signals for the

imino substituents and the r-butyl groups the

6

1 3 C[ H} NM R spectra each contain two separate

1

2

1

signals for the skeletal carbon atoms C-5 and C-

7 that experience strong param agnetic shifts and

appear between d = 43.5 and 50.1.

formation of the Staudinger products 22a-c

(Scheme 9).

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957

With less electrophilic azides such as alkyl or

aryl azides, on the other hand, the azatetraphos-

phaquadricyclane 6a does not show any tendency

to form the corresponding phosphane imines even

under drastic reaction conditions.

appears at <5 = 155.5, the signal of phosphorus

atom P-2 experiences an appreciably larger shift

to higher field of ca. 115 ppm and is found at d =

15.0. Only the chemical shift of the signal for P- 6

remains more or less unchanged at d = -147.4 in

comparison to that of 22b, whereas the signal for

P-4 is subject to a paramagnetic shift of about

50 ppm to (5 = 26.2. With the exception of the sig-

Twofold Staudinger reaction o f 6a with tosyl azide

(21b)

nals for the second substituent and the 1 3 C{ H}

1

W hen the reaction between 6a and tosyl azide

chemical shifts of the skeletal carbon atoms which

are markedly shifted to higher field and appear at

d = 36.6 and 37.4, the XH and ^C pH } NM R data

are in good agreement with those of com pound

22b.

(21b) was perform ed in a

1

: 2 m olar ratio the dou-

bly functionalized azaquadricyclane 23 was ob-

tained after crystallization as a pale yellow powder

in 74% yield (Scheme 10).

Although the single and double functionali-

zations of 6a by the Staudinger reaction can be real-

ized at 25 °C, higher degrees of functionalization

(three- and four-fold) of the azatetraphosphaqua-

dricyclane 6a cannot be achieved through reaction

with sulfonyl azides.

t-Bu

\

N 3

2 TsN3 (21b)

CH2CI2, 25 °C, 3 d

6a -----------------------------

Oxidative P/P bond cleavage in the quadricyclane

6a

Ts

23

The reaction of rBuN=VCl

Me, Ph) yields the stable phosphane complexes

['BuN=VCl -PR3] [18]. W hen the quadricyclane

6a was allowed to react with an equimolar am ount

of 15a for one week, no phosphane complex anal-

ogous to 17, 18 could be isolated, but the tricyclic

compound 24 was formed (Scheme 11). Excessive

15a does not lead to an oxidative cleavage of the

remaining P/P-bond in compound 24.

3

(15a) with PR (R =

3

Scheme 10

3

The E l mass spectrum clearly reveals the formal

composition of 23 originating from one molecule

of the tetracyclic starting m aterial 6a and two

molecules of tosyl azide (21b) with loss of two

molecules of nitrogen.

The 3 1 P{ H} NM R spectrum of product 23 con-

1

tains a total of four signal groups indicative of an

unsymmetrical structure. Thus, the occurrence of

the second functionalization at P- 6 - as is the case

for the second complexation - can be discounted.

In principle, the spectral data are compatible with

a functionalization at P-2 or P-4. However, when

the spin systems are analyzed a Vpp coupling con-

stant of 172.9 Hz is found and this unambiguously

dem onstrates that one diphosphirane unit has

been functionalized. Since in “simple” Staudinger

products the direct Vpp coupling decreases dra-

matically, it can be deduced with certainty that the

second Staudinger reaction has occurred at P-2.

The positions of the phosphorus signals are

strongly shifted in comparison to those of the

monofunctionalized product 22b. W hile the signal

of the primarily functionalized phosphorus atom

P-l is shifted by ca. 45 ppm to higher field and

t-Bu

\

f-BuN=VCI3 (15a)

k

toluene, 25 °C, 7 d

6a

-----------------------------

"f-B uN =V C r

p

-

/

Cl

24

Scheme 11

The construction of 24 from the quadricyclane

6a and two chlorine atoms is unambiguously de-

m onstrated by its mass spectral data. The isotope

pattern of the molecular ion peak at m/z - 403 in

the E l mass spectrum confirms the incorporation

of the two chlorine atoms in the product.

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Evaluation of the spin systems in the 3 1 P{

C. Peters et al. • Organophosphorus Compounds, Part 146

4a (0.40 g, 4.00 mmol). Subsequently the reaction

mixture was allowed to warm to 25 °C and stirred

for 12 h. A fter removal of the solvent under vac-

uum, the residue was chrom atographed over alu-

mina. The first yellow fraction («-pentane) was

collected and evaporated to dryness. The resultant

yellow solid was recrystallized from «-pentane

at -7 8 °C to yield the pure product 6a as pale yel-

low crystals (0.25 g, 76%): m.p. 76-77 °C.

1

H}

NM R spectrum clearly shows that one P/P bond

in the tetracyclic compound 6a has been cleaved

and the respective phosphorus atoms chlorinated

under the action of 15a. While the signals of the

phosphorus atoms P-l and P-7 appear at <3 = -9.1

(P-l) and -112.3 (P-7) with only minor shifts in

comparison to the corresponding signals for the

starting compound 6a, the signals for the phos-

phorus atoms P-3 and P-5 are markedly shifted to

lower field and now appear at <5 = 225.5 (P-3) and

93.9 (P-5). These drastic shifts to lower field of

3 1 P{

1

H} NM R (C D 6): -123.0, -7 .4 [A A 'X X '

6

spin system, /pp(A X , A 'X ') = 163.7, /pp(A A ') =

22.3, /p.p(XX')’ = 5.7, /pp(A 'X , A X ') - 2.3 Hz],

*H NM R (C

(t, / H.P = 0.9 Hz, 9H). 1 3 C{

6

D 6): 0.99 (d, JHP=1.2 Hz, 18H), 1.53

H} NM R (C D 6): 28.8-

1

6

more than

2

0

ppm are well known and are always

31.7 (m), 30.1 (mc), 32.1 (mc), 34.0 (t, / Cp = 10.6

observed when a P/P bond in a diphosphirane in-

crem ent is cleaved with concomitant halogenation

of the respective phosphorus atoms [21,22]. The

observed splitting patterns of the phosphorus sig-

nals are compatible only with the proposed consti-

tution for compound 25. Thus, the signals of the

phosphorus atoms P-l and P-7 of the retained di-

phosphirane unit appear as double doublets of

doublets on account of their coupling to three

other phosphorus atoms each, while the chlori-

nated phosphorus atoms P-3 and P-5 give rise to

double doublet signals as a result of the absence

of the direct lJPP coupling.

Hz), 56.8 (t, Jc p = 14.4 Hz). MS (E l, 70 eV): m/

z (% ) = 333 (63) [M+], 177 (100). -

C

1 4

H

2 7 NP

4

(333.26): calcd. C 50.45, H 8.16, N 4.20; found C

50.5, H 8.2, N 4.2.

5.7

-Di(l-adamantyl)-3-tert-butyl-3-aza-l,2,4,6-

tetraphosphatetracyclo[3.2.0.02,7.04,6]-heptane (6b)

To a stirred solution of 5a (0.32 g, 1.00 mmol) in

5 ml of toluene was added at -7 8 °C a solution of

4b (0.68 g, 4.00 mmol) in 2 mL of toluene. Subse-

quently the reaction mixture was allowed to warm

to 25 °C and stirred for 24 h. A fter removal of the

solvent under vacuum, the residue was chrom ato-

graphed over alumina. The first yellow fraction (n-

pentane) was collected and evaporated under vac-

uum. The resultant yellow residue consisting

mainly of 6b and bis(l-adam antyl)acetylene was

separated by bulb-to-bulb distillation (140 °C/10- 2

mbar) to give 6b as a yellow solid. Crystallization

from «-pentane at -7 8 °C afforded a pale yellow

powder (0.14 g, 34%).

Experimental Section

All reactions were perform ed under argon (pu-

rity > 99,998%; BTS catalyst, molecular sieve 5Ä)

using Schlenk techniques. The solvents were dried

by standard procedures, distilled, and stored under

argon until used. Column chromatography was

perform ed with a positive pressure of argon on the

column. Silica gel and alumina were heated

(175 °C) for 12 h under vacuum and then deacti-

vated with 4% water saturated with argon (Brock-

mann activity II). Melting points are uncorrected

(heating rate 2°/min). NM R (1H, 13C, 31P, 51V):

Bruker AC 200 and AM X 400; ö in ppm (298K)

3 1 P{

1

H} NM R (C D 6): -129.3, -14.9 [A A 'X X '

6

spin system, 7PP(AX, A 'X ') = 162.5, / PP(A A ') =

22.6, /pp(X X ') = 4.7, yPP(A 'X , A X ') = 1.7 Hz].

lH NM R (C

^C pH } NMR (C

6

D 6): 1.42-1^96 (m, 30H), 1.66 (s, 9H).

D 6): 28.7 (s), 30.0-32.9 (m), 33.2

6

(mc), 34.1 (t, / Cp = 10.5 Hz), 36.8 (s), 43.3 (mc),

56.8 (t, / Cp = 14.4 Hz). MS (El, 70 eV): m/z (% ) =

489 (50) [M+], 335 (100). HRMS: calcd 489.2033,

found 489.2004.

referenced to TMS (internal), 85% H

3

P 0

4

(exter-

nal), VOCI (external). MS: Finnigan MAT 90. IR:

3

Perkin Elm er FT-IR 16 P C. Starting Compounds

4a,c [23], 4b [24], 4d,e [25,26], 5a,b [27,28], 21a

[29], 21b [30] and 15a [31] were prepared by pub-

lished methods.

General procedure for the preparation o f the 3-aza-

1,2,4,6-tetraphosphaquadricyclanes 6c-e

To a solution of 5a (0.32 g,1.00 mmol) in 5 ml of

toluene the phosphaalkynes 4c, 4d, or 4f

(4.00 mmol) were added at -7 8 °C, the reaction

mixtures allowed to warm to 25 °C and stirred for

48 h (168 h in the case of 4f). The solvent was then

evaporated under vacuum and the dark brown re-

3,5,7-Tri-tert-butyl-3-aza-l,2,4,6-tetraphos-

phatetracyclo[3.2.0.02'7.046]heptane (6a)

To a stirred solution of 5a (0.32 g, 1.00 mmol) in

5 ml of toluene was added at -7 8 °C compound

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959

sidue chrom atographed over silica gel. From the

first yellow fraction («-pentane) the 1,3,5-triphos-

phabenzenes 7d,e were isolated as yellow oily resi-

dues. The second yellow band («-pentane/ether,

C

2 0

H

3

,N P

4

(413.39): calcd. C 58.11, H 8.53, N 3.39;

found C 57.0, H 8.4, N 3.1.

3-(l-Adamantyl)-5,7-di-tert-butyl-3-aza-l,2,4,6-

tetraphosphatetracyclo-[3.2.0.02'7.046]heptane (6f)

2

0

:1 ) was collected and evaporated under vacuum

to yield 6c, 6d, or 6e as yellow, viscous oils. The

products 6d and 6e were further purified by crys-

tallization from n-pentane at -7 8 °C.

To a stirred suspension of 5b (0.32 g, 1.00 mmol)

in 5 ml of toluene was added 4a (0.40 g,

4.00 mmol) at -7 8 °C. Subsequently the reaction

mixture was allowed to warm to 25 °C and stirred

for 12 h. A fter removal of the solvent under vac-

uum, the residue was chrom atographed over alu-

mina. The first yellow fraction (n-pentane) was

collected and evaporated under vacuum. The yel-

low residue was crystallized from n-pentane at

-7 8 °C to yield yellow crystals (0.14 g, 34%).

3-tert-Butyl-5,7-bis(l,l-dimethylpropyl)-3-aza-

1.2.4.6-tetraphosphatetracyclo-

ß^.O.ft^.tf^Jheptane (6c)

Yellow, viscous oil (0.19 g, 53%).

3 1 P{

1

H} NM R (C D 6): -123.2, -9.2 [A A 'X X '

6

spin system, 7PP(AX, A 'X ') = 162.3, / PP(A A ') =

24.3, yP,P(X X ')’ = 6.2, / PP(A 'X , A X ') = 1.4 Hz].

3 1 P[

1

H} NM R (C D 6): -124.8, -13.5 [A A 'X X '

6

spin system, / PP(AX, A 'X ') = 161.0, 7PP(A A ') =

21.5, 7PP(X X ') = 5.8, / PP(A 'X , A X ') = 1.9 Hz],

XH NM R (C

Hz, H), 1.18 (s,

^C pH ] NM R (C

6

D 6): 0.85 (s,

6

H ), 0.88 (t, 7Hh = 7.5

6

H), 1.52 (mc, 4H), 1.61 (s, 9H).

D 6): 9.1 (s), 26.8 (mc), 28.6 (mc),

:H NM R (C

(mc, H), 1.99 (mc, 3H), 2.38 (mc,

NM R (C D 6): 29.8-31.7 (m), 29.9 (mc), 30.7 (s),

6

D 6): 1.12 (d^7H p = 1.2 Hz, 18H), 1.54

6

H). -

28.7-31.3 (m), 34.2 (t, JCP = 10.4 Hz), 34.7 (mc),

35.2 (mc), 56.6 (t, Jc P = 13.6 Hz). MS (El, 70 eV):

m/z (% ) = 361 (72) [M+], 57 (100).

6

32.3 (mc), 36.0 (s), 47.8 (t, JCP = 10.9 Hz), 57.1 (t,

JCP = 12.9 Hz). MS (El, 70 eV): m/z (% ) = 411

(28) [M+], 135 (100).

3-tert-Butyl-5,7-bis(l-methylyclopentyl)-3-aza-

1.2.4.6-tetraphosphatetracyclo-

[3.2.0.02’7.04,6]heptane (6d)

l-r]-[3,5,7-Tri-tert-biityl-3-aza-l,2,4y6-tetra-

phosphatetracyclo[3.2.0.02’

[tetracarbonyliron (0)] (17)

7

.04,6]heptane]-

Pale yellow crystals (0.22 g, 57%); m.p. 73 °C.

3 1 P{

1

H} NM R (C D 6): -123.8, -5 .8 [A A 'X X '

6

spin system, 7PP(AX, A 'X ') = 161.0, 7PP(A A ') =

23.5,7PP(X X ') = 5.5, / PP(A 'X , A X ') = 1.3 Hz], XH

A suspension of 6a (0.40 g, 1.20 mmol) and di-

iron nonacarbonyl (0.44 g, 1.20 mmol) in 5 ml of

toluene was stirred at 25 °C for 24 h. A fter re-

moval of the solvent under vacuum, the residue

was taken up in 5 ml of «-pentane and filtered

through a D3 glass sinter filled to a depth of 3

cm with Celite. A fter two washings with «-pentane

(5 ml each), the combined filtrates were evapo-

rated to dryness. The resultant solid was chro-

m atographed over alumina. The first yellow frac-

tion (/i-pentane) was collected and evaporated

under vacuum to furnish a mixture of 17 and un-

changed 6a. R epeated crystallizations from n-

pentane at -7 8 °C afforded yellow crystals of pure

17 (0.24 g, 40%).

NM R (C

1.60 (s, 9H). ^C pH ] N M R (C

6

D 6): 1.02 (s,

6

H ), 1.10-2.10 (m, 16H),

D 6): 24.5 (s), 25.4

6

(mc), 28.8-31.4 (m), 34.1 (t, Jcv = 10.4 Hz), 39.3

(mc), 42.1 (mc), 43.5 (mc), 56.8 (t, JCP = 13.6 Hz).

MS (E l, 70 eV): m/z (% ) = 385 (76) [M+], 259

(

1

0

). -

C

1 8

N

3 1 NP

4

(385.34): calcd. C 56.10, H

8.11, N 3.63; found C 56.8, H 8.5, N 3.5.

3-tert-Butyl-5,7-bis(l-methylcyclohexyl)-3-aza-

1.2.4.6-tetraphosphatetracyclo-

P^.O.ff^.f^^Jheptane (6e)

Pale yellow crystals (0.19 g, 47%); m.p. 76 °C.

^P ^H } NM R (C

6

D 6): -125.3, -11.9 [A A 'X X '

3 1 P[

1

H] NM R (C D 6): -127.2 (dd, 7PP = 168.7,

6

spin system, / PP(AX, A 'X ') = 160.9, 7PP(A A ') = 7.4 Hz), -40.7 (dpt, JPP= 179.1, 7.0 Hz); -9.1 (dd,

23.3, / PP(X X ')’ = 5.6, / PP(A 'X , A X ') = 1.3 Hz], 7PP = 179.1, 23.2 Hz), 20.1 (ddd, JPP = 168.7, 23.2,

XH NM R (C

6

D 6): 1.05-2.02 (m, 20H), 1.33 (s,

6

H),

6

. 6 Hz). :H NM R (C

6

D 6): 1.02 (s, 9H), 1.04 (s,

1.68 (s, 9H). 1 3 C{

1

H}NMR (C D 6): 22.2 (d, JCP = 9H), 1.44 (s, 9H). ^C pH } NM R (C

6

D 6): 30.1 (mc),

13.6 Hz), 23.6 (s), 26.0 (d, JCP = 5.6 Hz), 28.6-

30.6 (m), 31.0 (s), 33.7 (t, Jc P = 10.4 Hz), 34.5 (mc),

38.6 (mc), 39.8 (s), 56.4 (t,’/ Cp = 13-6 Hz). MS

(El, 70 eV): m/z (% ) = 413 (34) [M+], 57 (100). -

30.7 (mc), 33.0 (mc), 34.0 (pt, JCP = 10.0 Hz), 57.3

(pt, JCP = 14.0 Hz), 217.3 (dd, 7Cp = 12.1, 2.3 Hz).

IR (w-pentane): v = 2060 (C=

6

), 1982 (C = 0),

1965 (C = 0) cm“1. MS (El, 70 eV): m/z (% ) = 501

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C. Peters et al. • Organophosphorus Compounds, Part 146

(<1) [M+], 389 (100). - C 1 8

calcd. C 43.14, H 5.43, N 2.80; found C 43.2, H 5.4,

N 2.7.

H

2 7 F eN 0

4

P

4

(501.16):

3 1 P{

1

H} NM R (C

19.6 (d, 7pp = 191.8 Hz). XH N M R (C

18H), 1.37 (s, 9H). 1 3 C{ H} N M R (C

6

D 6): -43.9 (d, / P,P = 191.8 Hz),

D 6): 1.12 (s,

D 6): 30.5

6

1

6

(mc), 34.0 (mc), 34.0 (t, / Cp = 10.0 Hz), 44.5 (mc),

58.0 (t, Jc p = 14.0 Hz), 216.8 (d, / CP = 11.2 Hz).

IR (n-pentane): v = 2068 (C = 0 ), 2059 (C = 0),

1989 (C = 0), 1983 (C = 0), 1970 (C = 0 ) cm“1. - MS

(El, 70 eV): m/z (% ) = 669 (<1) [M+], 57 (100).

l-rj-[3,5,7-Tri-tert-butyl-3-aza-l,2,4,6-tetra-

phosphatetracyclo[3.2.0.02,7.046]heptane]-

[pentacarbonyltungsten] (18)

A

solution of tungsten hexacarbonyl (0.12 g,

C

2 2

H

2 7 Fe

2

N

0

8

P4 (669.04): calcd. C 39.49, H 4.07,

0.34 mmol) in 60 ml of TH F was placed in a pho-

tolysis apparatus and irradiated under cooling with

water for 25 min using a m edium -pressure m er-

cury lamp, which resulted in the form ation of the

tungsten pentacarbonyl-TH F complex. During this

time the color of the reaction mixture changed

N 2.09; found C 39.8, H 3.9, N 2.0.

jU-l:6-rj:rj-[3,5,7-Tri-tert-butyl-3-aza-l,2,4,6-

tetraphosphatetracyclo[3.2.0.02,

7

.046]-heptane]-

bis[pentacarbonyltungsten] ( )

2

0

A

solution of tungsten hexacarbonyl (0.40 g,

from colorless to yellow. Then a solution of

6

a

1.13 mmol) in 60 ml of TH F was placed in a pho-

tolysis apparatus and irradiated under cooling with

water for 25 min using a medium-pressure m er-

cury lamp, which resulted in the formation of the

tungsten pentacarbonyl-TH F complex. During this

time the color of the reaction mixture changed

(0.10 g, 0.30 mmol) in 5 ml of TH F was added and

the mixture stirred for 24 h. The solvent was evap-

orated under vacuum and the yellow residue was

subjected to column chrom atography on silica gel.

The first yellow fraction (n-pentane) was collected

and evaporated under vacuum to furnish a mixture

from colorless to yellow. Then a solution of

6

a

of 18 and traces of unchanged

tallizations from n-pentane at -7 8 °C afforded

yellow crystals of pure 18 ( g, 61%).

H} NM R (C D 6): -130.9 (dd, Jvv = 172.2,

6

a. R epeated crys-

(0.15 g, 0.45 mmol) in 5 ml TH F was added and

the mixture stirred for 24 h. The solvent was eva-

porated under vacuum and the yellow residue was

placed in a sublimation apparatus to remove un-

0

. 1 2

3 1 P{

1

6

6.0 Hz), -104.1 (dpt, /p,p = 151.7, 6.0 Hz), 1.9 (dd,

/pp = 151.7, 21.4 Hz), 12.3 (ddd, / RP = 172.2, 21.4,

changed tungsten hexacarbonyl. After

2 h at

40 °C/10 m bar the tungsten hexacarbonyl was

~

2

6

.Ö Hz). *H NM R (C

6

D 6): 1.04 (s, 9H), 1.05 (s,

D 6): 30.3 (mc),

completely removed, the residue was taken up in

5 ml of diethylether and filtered through a D3

glass sinter filled to a depth of 3 cm with silica

gel. A fter two washings with ether (5 ml each), the

combined filtrates were evaporated to dryness.

The yellow residue was purified by crystallization

from rc-pentane at -7 8 °C providing pure 20 as a

yellow solid (0.21 g, 47%).

9H), 1.44 (s, 9H). 1 3 C{ H} N M R (C

1

6

32.7 (mc), 33.9 (pt, Jc P = 10.0 Hz), 36.5 (mc), 38.3

(mc), 57.5 (pt, Jc p =’ 14.0 Hz), 196.8 (dd, JCP =

6.3, 2.7, Jc,

w

=

126.8 Hz), 197.8 (d,

/

c

,p = 31.4,

JCw - 150.8 Hz). IR (n-pentane): v = 2074 (C = 0),

1949 (C = 0), 1919 (C = 0) cm “1. MS (El, 70 eV):

m/z (% )

=

657

(

6

)

[M+], 177 (100).

-

Q

9

H

2 7 N O

5

P

4

W (657.17): cald. C 34.73, H 4.14, N

3 1 P{

1

H} NM R (C

7pW = 228.0 Hz), 21.7 (d, / P)P= 159.8 Hz). XH NM R

(C D 6): 1.28 (s, 9H), 1.29 (s, 9H), 1.76 (s, 9H).

H} NM R (C D 6): 31.0 (mc), 33.3 (mc), 34.3 (t,

6

D 6): -111.9 (d, /p P = 159.8,

2.13; found C 34.7, H 4.2, N 2.1.

6

f,i-l:6-r\:r]-[3,5,7-Tri-tert-butyl-3-aza-l,2,4,6-

1 3 C{

1

6

tetraphosphatetracyclo[3.2.0.02' .04,6]-heptane]-

bis[tetracarbonyliron(0)] (19)

7

Jc p = 10.2 Hz), 41.9 (mc), 58.6 (t, JCP = 14.0 Hz),

196.0 (mc), 196.8 (d, Jc P = 33.9 Hz). IR (n-

pentane): v = 2073 (C = 0), 1983 (C = 0), 1957 (C = 0),

1949 (C = 0) cm “1. MS (El, 70 eV): m/z (% ) = 981

A suspension of

6

a (0.15 g, 0.45 mmol) and di-

iron nonacarbonyl (0.33 g, 0.90 mmol) in 5 ml of

toluene was stirred at 25 °C for 24 h. A fter re-

moval of the solvent under vacuum, the residue

was taken up in 5 ml of «-pentane and filtered

through a D3 glass sinter filled to a depth of 3 cm

with alumina. A fter two washings with /i-pentane

(5 ml each), the combined filtrates were evapo-

rated to dryness. The resultant yellow solid was

purified by crystallization from «-pentane at

(10) [M+], 517 (100). C2 4

H

2 7 N O 1 0

P

4

W

2

(981.07):

calcd. C 29.38, H 2.77, N 1.43; found C 28.8, H 2.8,

N 1.5.

General procedure for the preparation o f the

Staudinger products 22a-c

A solution of

6

a (0.15 g, 0.45 mmol) and the

azides 21a, 21b, or 21c (0.45 mmol) in 4 ml of di-

-7 8 °C providing yellow crystals of pure 19 chlorom ethane was stirred for 48 h. The solvent

was evaporated under vacuum and the colorless to

(0.07 g, 24%).

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pale yellow residue was washed 3 times with cold

(3 °C) «-pentane (2 ml each). Crystallization from

dichlorom ethane at -7 8 °C afforded pure 22a,b,c

as colorless solids.

15.6 (s), 24.0 (s), 26.2 (s), 34.1 (pt, JCP = 11.4 Hz),

34.7 (mc), 35.7 (mc), 45.7 (mc), 50.1 (mc), 60.9 (pt,

JCP = 17.8 Hz), 120.7 (s), 129.2 (s), 137.6 (s), 144.2

(sj, 170.8 (s). IR (CCU): v = 1708 cm

“

1

(C = 0). MS

(El, 70 eV): m/z (% ) = 545 (10) [M+], 177 (100).

3.5.7- Tri-tert-butyl-1-(4-methylsulfonylimino)-

3-aza-l,2,4,6-tetraphosphatetracyclo-

3,5,7-Tri-tert-butyl-1,2-ditosylimino-3-aza-l,2,4,6-

[3.2.0.Ö2’7.04,6]heptane (

2

a)

tetraphosphatetracyclo-[3.2.0.02'7.046]heptane (23)

Colorless powder (0.15 g, 78%); m.p. 120 °C

(decomp.).

A solution of 6a (0.20 g, 0.60 mmol) and tosyl

azide (21b) (0.24 g, 1.20 mmol) in 5 ml of dichloro-

m ethane was stirred for 3 d. The solvent was evap-

orated under vacuum and the colorless to pale yel-

3 1 P{

1

H} NM R (C

6

D 6): -144.6 (ddd, 7PP = 175.4,

31.1, 14.5 Hz), -21.0 (ddd, 7PP = 175.4, 20.5, 9.7

Hz), 132.1 (ddd, 7pP = 31.1, 9.7, 4.5 Hz), 199.9 low residue was washed 3 times with «-pentane

(ddd, 7PP = 20.5, 14.5, 4.5 Hz). - *H NM R (C

0.97 (s, 9H), 1.17 (s, 9H), 1.50 (d, / H p = 1-4 Hz,

9H), 2.38 (s, 3H). - ^C pH } NM R (C D 6): 28.8

6

D 6):

(2 ml each). Crystallization from dichlorom ethane

at -7 8 °C afforded pure 23 as a pale yellow pow-

der (0.30 g, 74%); m.p. 110 °C (decomp.).

6

(dpt, JCP = 10.0, 7.2 Hz), 29.0 (dd, JCP = 9.2, 8.0

Hz), 32.5 (pt, JCP = 11.0 Hz), 32.8-33.3 (m), 34.1-

34.5 (m), 41.6 (s), 46.7-47.9 (m), 59.3 (pt, 7Cp =

18.3 Hz). - MS (El, 70 eV): m/z (% ) = 426 (12)

[M+], 111 (100).

^P pH } NM R (CD C12): -147.4 (dpt, JPP =

172.9, 13.6 Hz), 15.0 (pt, / pP = 13.6 Hz), 26.2 (dd,

7PP = 172.9, 23.7 Hz), 155.5 (dpt, 7PP = 23.7, 13.6

2

Hz). lH NM R (CD

1.63 (s, 9H), 2.38 (s,

2

C12): 1.11 (s, 9H), 1.32 (s, 9H),

H), 7.25 (d, / H h = 7.8 Hz,

6

2H), 7.27 (d, JHH = 8.3 Hz, 2H), 7.84 (d, 7Hh =

8.3 Hz, 2H), 7.94 (d, 7Hh = 7.8 Hz, 2H). - ^C ^H }

3.5.7-Tri-tert-butyl-l-tosylimino-3-aza-l,2,4,6-

tetraphosphatetracyclo[3.2.0.02,7.04'6]-heptane

(22b)

NM R (CD C12): 23.5 (s), 23.7 (s), 31.9 (pt, 7CP =

2

10.2 Hz), 32.6 (dd, JCp = 15.2, 8.5 Hz), 33.9 (mc),

35.2 (pt, / Cp - 10.6 Hz), 36.6 (mc), 37.4 (mc), 61.9

(pt, JCP = 17.8 Hz), 128.3 (s), 128.6 (s), 131.2 (s),

131.8 (s), 144.0 (s), 144.6 (s), 145.2 (s), 146.9 (s). -

Colorless powder (0.19 g, 83%); m.p. 128 °C

(decomp.).

3 1 P{

1

H} NM R (C D 6): -146.7 (ddd, 7PP = 175.0,

6

MS (El, 70 eV): m/z (% ) = 671 ( ) [M+], 91 (100).

6

30.6, 14.1 Hz), -22.2 (ddd, 7PP = 175.0, 20.5, 10.5

Hz), 130.8 (ddd, 7PP = 30.6, 10.5, 5.9 Hz), 198.6

2,4,6-Tri-tert-butyl-3,5-dichloro-2-aza-l,3,5,7-

(ddd, Jpp = 20.5, 14.1, 5.9 Hz).

(CD C12): 1.18 (s, 9H), 1.26 (s, 9H), 1.82 (d, / Hp =

1.2 Hz, 9H), 2.60 (s, 3H), 7.50 (d, JHH =

2H), 7.88 (d, 7Hh = . 8 Hz, 2H). - ^C pH } NM R

(CD C12): 20.7 (s), 27.7 (dd, JCP = 17.0, . 8 Hz), 6a (0.11 g, 0.34 mmol) in 5 ml of toluene at 25 °C

-

XH NMR

tetraphosphatricyclo[2.2.1.067]heptane (24)

2

8

. 8 Hz,

To a stirred solution of 15a (0.08 g, 0.34 mmol)

8

in 5 ml toluene was added dropwise a solution of

2

6

28.0 (pt, JCP = 8.7 Hz), 31.8 (pt, Jc P = 11.0 Hz),

32.4 (mc), 33.4 (mc), 43.5 (mc), 47.6 (mc), 58.5 (pt,

Jc p = 18.2 Hz), 125.8 (s), 128.9 (s), 138.3 (s), 142.6

and the mixture stirred for 7 d. A fter removal of

the solvent under vacuum, the residue was taken

up in a mixture of 5 ml of n-pentane and 5 ml of

(s). - MS (El, 70 eV): m/z (% ) = 502 (17) [M+], toluene and then filtered through a D4 glass sinter.

91 (100). C P4S (502.46); calcd. C 50.20, The filtrate was concentrated to 10% of its vol-

2

iH 3 4

N

2 0

2

H 6.82, N 5.58; found C 49.1, H 6.7, N 5.9.

ume. Cooling to -7 8 °C and filtration furnished 24

as a colorless powder ( g, 18%).

^P ^H } NM R (C D 6): -112.3 (ddd, 7PP = 207.5,

44.8, 12.2 Hz), -9.1 (ddd, 7PP = 207.5,' 20.4, 8.1

Hz), 93.9 (dd, 7P,P = 44.8, 8.1 Hz), 225.5 (dd, 7PP =

0

. 0 2

6

3.5.7- Tri-tert-butyl-1-[(4-acetamido)phenyl-

sulfonylimino]-3-aza-l,2,4,6-tetraphosphate-

tracyclo[3.2.0.02'7.04,6/heptane (22c)

20.4, 12.2 Hz). 1-H NM R (C D 6): 1.03 (pt, 7H p =

6

Colorless powder (0.19 g, 78%); m.p. 134 °C

(decomp.).

1.3 Hz, 9H), 1.32 (d, i H p = 1.5 Hz, 9H), 1.54 (d,

7H p - 2.2 Hz, 9H). - MS (El, 70 eV): m/z (% ) =

403 (44) [M+], 266 (100).

3 1 P{

1

H} NM R (CD C12): -142.7 (ddd, 7PP =

2

175.2, 31.5, 13.8 Hz), -19.6 (d d d ,/pP= 175.2, 19.7,

9.0 Hz), 133.9 (ddd, 7PP = 31.5, 9.0,' 6.1 Hz), 203.2

(ddd, JPP = 19.7,13.8, 6.1 Hz). XH NM R (CD

0.93 (s, 9H), 1.03 (s, 9H), 1.57 (s, 9H), 2.11 (s, 3H),

7.68 (s, 4H), 8.39 (s, 1H). ^C ^H } NM R (CD

1,3,4-Tri-tert-butyl-l,2,5-azadiphosphole (11a)

Phosphaalkyne 4a (0.11 g, 1.10 mmol) at -7 8 °C

C12): was added to a stirred solution of 5a (0.17 g,

2

C12):

2

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962

C. Peters et al. • Organophosphorus Compounds, Part 146

0.53 mmol) in 12 ml of toluene. The mixture was

allowed to warm up, and stirred for 30 min at

room tem perature, and then the solvent was evap-

CCM e3), 59,4(t, 2JCP = 12,7 Hz, NCM e3), 180.7

(dd, Vc.p = 47.5 Hz, 2/ CP - 11.4 Hz, CCM e3).

(NM R data were determ ined from a mixture of

orated under vacuum. A fter extraction with n- 6a/lla; the signals of pure 6a are known).

ml), the solvent was distilled off under

reduced pressure, and the residue purified by

bulb-to-bulb distillation (140 °C/10 mbar) yield-

pentane ( 2

0

Acknowledgements

2

ing an inseparable mixture of quadricyclane 6a

and 1,2,5-azadiphosphole 11a.

We thank the Fonds der Chemischen Industrie

for generous financial support and for a post-grad-

uate grant (to C. Peters). We are also grateful to

the Deutsche Forschungsgemeinschaft (G raduier-

tenkolleg “Phosphorus as Connecting Link Be-

3 1 P{XH} NM R (C

(C D 6): 1.59 (t, 4Jh p = 0.9 Hz, 9H), 1.66 (d, V HP =

3.0 Hz, 18H). - ^C pH } NM R (C D 6): 34.9 (t,

6

D 6): 285.8 (s). - *H NMR

6

3/ c p = 9.3 Hz, NCMe3), 35.3 (d, 3/ CP = 19.5 Hz, tween Various Chemical Disciplines”) for a post-

graduate grant (to A. Nachbauer).

CCMe3), 37.6 (dd, 2/ CP = 27.2 Hz, 3/ Cp = 1-7 Hz,

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Organophosphorus compounds, part 146 imidovanadium(V) complexes as reaction partners for kinetically stabilized phosphaalkynes. Synthesis and reactivity of 3-Aza-1,2,4,6-tetraphospha-quadricyclanes

DOI: 10.1515/znb-2001-0915

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