Proazaphosphatrane P(RNCH2CH2)3N (R = Me, i-Pr)-catalyzed isomerization of allylaromatics, allyl phenyl sulfide, allyl phenyl sulfone, and bis-allymethylene double bond-containing compounds

Article abstract of DOI:10.1002/adsc.200505224

Using a proazaphosphatrane catalyst, P(RNCH₂CH₂) ₃N (R = Me, i-Pr), allylaromatics and allyl phenyl sulfide were selectively isomerized to the corresponding vinyl isomers in yields up to > 99% in CH₃CN at 40°C. Efficient transformation of allyl phenyl sulfone at ambient temperature afforded an isomerization/dimerization product in >95% yield. Conjugation of bis-allylmethylene double bond-containing compounds gave the corresponding conjugated isomers for cis,cis-9,12- octadecadienol and its methyl ether in yields up to 97%, and desilylation/conjugation products were obtained from the catalytic reaction of the trimethylsilyl ether of cis,cis-9,12-octadecadienol. The reaction mechanism is discussed based upon the ¹H and ³¹P NMR-monitored reactions in CD₃CN or CH₃CN under the reaction conditions.

Full text of DOI:10.1002/adsc.200505224

FULL PAPERS
DOI: 10.1002/adsc.200505224
Proazaphosphatrane P(RNCH2CH2)3N (R¼Me, i-Pr)-Catalyzed
Isomerization of Allylaromatics, Allyl Phenyl Sulfide, Allyl
Phenyl Sulfone, and bis-Allylmethylene Double Bond-Containing
Compounds
Zhengkun Yu,a,* Shenggang Yan,b Guangtao Zhang,c Wei Hea,*,
Liandi Wang,a Yu Li,a Fanlong Zenga
a
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023,
Peopleꢀs Republic of China
Fax: (þ86)-411-8437-9227, e-mail: zkyu@dicp.ac.cn
b
The Department of Chemistry, Dalian University of Technology, Dalian, Liaoning 116024, Peopleꢀs Republic of China
c
On leave from Chinese Academyof Sciences, P. R. China
Received: May31, 2005; Accepted: September 30, 2005
Supporting Information for this article is available on the WWW under http://asc.wiley-vch.de/home/.
Abstract: Using
a proazaphosphatrane catalyst, tion/conjugation products were obtained from the cat-
P(RNCH2CH2)3N (R¼Me, i-Pr), allylaromatics and alytic reaction of the trimethylsilyl ether of cis,cis-
allyl phenyl sulfide were selectively isomerized to 9,12-octadecadienol. The reaction mechanism is dis-
1
the corresponding vinyl isomers in yields up to > cussed based upon the H and 31P NMR-monitored
99% in CH3CN at 408C. Efficient transformation of reactions in CD3CN or CH3CN under the reaction
allyl phenyl sulfone at ambient temperature afforded conditions.
an isomerization/dimerization product in >95%
yield. Conjugation of bis-allylmethylene double
bond-containing compounds gave the corresponding Keywords: allylic compounds; isomerization; methyl-
conjugated isomers for cis,cis-9,12-octadecadienol ene-interrupted diene compounds; proazaphospha-
and its methyl ether in yields up to 97%, and desilyla- trane; P(RNCH2CH2)3N
Introduction
the absence of a solvent.[15] In absolute ethanol, allylben-
zenes were isomerized to the trans products with sodium
Ever since Shimizu and Blum first reported the isomer- ethoxide under refluxing conditions.[16] Allylbenzene
ization of allylbenzene using Natta-type catalyst[1a] and was isomerized with K2CO3 and a phase-transfer cata-
platinum complex catalysts,[1b] a wide arrayof com-
lyst.[17] Using polyethylene glycol as the phase-transfer
plexes of transition metals, such as palladium,[2] rutheni- catalyst KOH also isomerized p-allylanisole.[18] Under
um,[3] rhodium,[4] nickel,[5] cobalt,[6] iron,[7] titanium,[7b,8] phase-transfer conditions allylbenzene was also isomer-
and zirconium[8d,9] have been utilized for this purpose. ized with aqueous NaOH in hydrocarbon solvents.[19]
Organolanthanide complexes Cp3Y catalyzed the Under microwave irradiation KOH in alcohols efficient-
isomerization of allylbenzene to achieve a trans/cis lyisomerized safrole and eugenol. [20] The electrogener-
ratio of 91/9 for the corresponding isomerized prod- ated triphenylmethyl anion acted as a base to isomerize
ucts.[10] Isomerizations of p-allylanisole[2b,3a,4c] and saf- allylaromatics.[21]
role[6a,7b,8a,8c,11] were also realized with transition metal
Isomerization of allyl sulfides has been reported with
catalysts, respectively. 2,4-Dimethoxyallybenzene was NaOH or NaOEt,[22a, b] Pd(PCy3)2 (PCy3 ¼tricyclohexyl-
even isomerized on Pb/Al2O3.[12] Base-catalyzed isomer- phosphine),[22c]
or
tris(2,4-pentanedionate)ruthe-
izations of allylaromatics have been reviewed.[13] Potas- nium.[22d] Basic thermal isomerization of allyl aryl sul-
sium fluoride on alumina isomerized safrole in 76% fides occurred in quinoline at 2408C.[23] Isomerization
yield,[14] while KOH or t-BuOK isomerized safrole to of allyl to vinyl sulfones catalyzed by various bases has
form the corresponding trans product in 99% yield in received much attention from organic chemists.[13,24] All-
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yl phenyl sulfone was transformed into vinyl phenyl sul-
fone with NaOH in CH2Cl2 under phase transfer condi-
tions.[4c] Recently, the isomerization of allylic com-
pounds and methylene-interrupted dienes was realized
[25]
ꢀ
with the non-ionic phosphazene strong base P2 Et.
Conjugation of methylene-interrupted carbon-carbon
double bonds has aroused much attention due to new
potential applications of vegetable oils such as soybean
Scheme 1.
oil and safflower oil, and polyunsaturated fatty acids and Results and Discussion
their derivatives.[26] Transition metal complexes are
known for this goal.[27] Base-catalyzed conjugation of Proazaphosphatranes are powerful non-ionic bases
CH2-interrupted carbon-carbon double bonds em- forming remarkablystable azaphosphatrane cations
ployed t-BuOK[28] and alkali,[29] respectively. Thionyl 2a–c. The conjugate acids, i.e., 2b of superbase 1b, and
chloride[30] and toluene-p-sulfonic acid[31] were also re- 2c of superbase 1c have been shown to have pKa values
[35c]
ported as the catalysts for isomerization of fatty oils, of 32.90 and 33.63 in acetonitrile, respectively.
The
methyl linoleate, and relatedesters. Inthe case of methyl equilibrium shown in Eq. (1) (Scheme 2) has been es-
linoleate, a ca. 80% isomerization yield was obtained via tablished in CH3CN.[35, 38]
a radical-induced mechanism byiodine. [32]
Using transition metal catalysts, dimerization, poly-
merization and hydrogenation were the side reactions
in the above-mentioned isomerization or conjugation
procedures. Under ionic basic conditions, geometrical
selectivities for the conjugated dienes were higher
than those using transition metal catalysts, but low yields
of the corresponding products and loss of ester groups
were quite common. Although these results have been Scheme 2.
achieved, more efficient procedures for isomerizing al-
lylaromatic and fatty olefinic compounds are still being
pursued.
Using the superbase catalysts 1b or 1c allylaromatics
Synthetic applications of exceedingly strong non-ionic 3a–7a (Scheme 2) were exclusivelyconjugated to vinyl-
bases and catalysts of type 1 have been well documented aromatics with the corresponding trans-isomers as the
since theywere first reported from Verkadeꢀs laborato-
major products (Table 1), while cis-isomers are predom-
ries.[33–35] It has been demonstrated that the nucleophi- inantlyformed from isomerization of the same sub-
licityand basicityof 1 steming from transannular bond strates bymeans of transition metal complexes or ionic
formation playimportant roles in the formation and sta-
bases. Substituent(s) on the phenyl group lessened the
bilityof cationic intermediates of type 2 (Scheme 1). reaction rate. Predominant formation of trans vinyl
Both 1b and 1c are known strong non-ionic bases that products suggests that the allyl anion formed during
can deprotonate acetonitrile,[33d] benzylnitrile,[33d] and the reaction bydeprotonation of the substrate with the
other activated methylene groups,[36] resulting in a vari- in situ generated ꢀCH2CN anion lived long enough to af-
etyof reactions initiated byanions such as ꢀCH2CN gen- ford the more thermodynamically stable diastereoisom-
erated by 1b or 1c from CH3CN, etc. Our recent prelimi- ers. With 10–50 mol % of the proazaphosphatrane cat-
narywork demonstrated the catalytic dimerization of
alysts, 100% conversion for the allylaromatics 3a–6a
allyl phenyl sulfone by superbases of type 1,[37] which and up to 99% isolated yields for the conjugated prod-
led us to investigate isomerization of allyl-containing ucts were obtained (Table 1). Under the same condi-
or CH2-interrupted carbon-carbon double bond-con- tions, trans-b-methylstyrene, i.e., (E)-3b, did not under-
taining compounds byusing 1b and 1c as the catalysts. go isomerization to form allylbenzene 3a as monitored
Herein, we report the isomerization of allylaromatics, proton NMR measurements, revealing that the super-
allyl phenyl sulfide, allyl phenyl sulfone, methylene-in- bases cannot deprotonate vinylic CH or non-activated
terrupted carbon-carbon double bond-containing cis,- CH3 functions. Conjugation reactions of 3a–6a were
cis-9,12-octadecadienol and its derivatives, in CH3CN also carried out in CD3CN in a 5-mm NMR tube at
at 408C byusing 1b or 1c as the catalyst. The highlights 408C and monitored by 1H NMR determinations. With
of the present work are: (a) Isomerization or conjuga- 0.05 equivs. of 1b, allylbenzene (3a), was conjugated to
tion proceeded under verymild conditions and the reac-
(E)-1-phenylpropene [(E)-3b] in 50% yield over a peri-
tions were catalytic. (b) High yields and selectivities od of 14 hours, and the 31P NMR spectrum of the reac-
were achieved for the aimed products. (c) The reactions tion mixture onlyexhibited three equal intensitylines
could be convenientlymonitored by 1H and 31P {1H} which centered at d(P ¼ ꢀ10.4 ppm and are assigned
ꢀ
D)
NMR measurements.
to the deuterated form of 1b, i.e., 1bDþ. The result
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Proazaphosphatrane P(RNCH2CH2)3N (R¼Me, i-Pr)-Catalyzed Isomerizations
Table 1. Isomerization of allylaromatics using 1b or 1c as the catalyst.[a]
FULL PAPERS
Substrate
Base (equivs.)
Time [h]
Conversion[b] [%]
Eluent ratio[c]
Product
Yield[d] [%] (E/Z)
3a
3a
1b (0.1)
1c (0.1)
24
10
100
100
10: 1
10: 1
94.0[e] (99/1)
93.0[e] (98/2)
4a
4a
1b (0.4)
1c (0.15)
72
60
90.2
100
10: 1
10: 1
90.0 (94/6)
96.3 (94/6)
5a
5a
5a
1b (0.2)
1b (0.5)
1c (0.4)
120
120
96
48.0
90.1
100
5: 1
5: 1
5: 1
47.4 (89/11)
90.0 (89/11)
99.4 (90/10)
6a
6a
1b (0.3)
1c (0.15)
60
30
100
100
10: 1
10: 1
98.0 (93/7)
95.3 (94/6)
7a
7a
7a
1b (0.82)
1b (1.57)
1c (1.57)
72
96
96
–
37.0
43.0
5: 1
5: 1
5: 1
–
36.0 (91/9)
42.0 (92/8)
[a]
Reaction conditions: 0.1 MPa, 408C; substrate, 1.0 mmol; CH3CN, 5 mL.
Determined by H NMR.
[b]
[c]
[d]
[e]
1
n-Hexane/THF.
Isolated yields from TLC or column chromatography on silica gel, products are >98% purityby 1H NMR measurements.
>99% yield according to GC analysis of the reaction mixture but the isolated yields are lower than the reported results due
to the volatilityof the product.
also revealed that all the catalyst was deuterated by the urement of the mixture of 7a and 0.2 equivs. of 1b in CD3
solvent and the ꢀCD2CN anion was generated during CN at 408C revealed that 1b was predominantlycon-
the reaction. 64 hours later 74% of 3a was conjugated verted to form A [singlet, d(P ¼ ꢀ9.9 ppm] byextract-
ꢀ
H)
and the 31P NMR measurements showed no further in- ing a phenolic proton from 7a, and onlytrace of 1bDþ,
crease of its conversion upon extending the reaction i.e., species B [evidenced bythe three-line resonance
time. However, 3a was completelyconjugated to ( E)- at d(P ¼ ꢀ10.4 ppm] was detected. These results indi-
ꢀ
D)
3b in CD3CN within 24 hours bymeans of 0.10 equiv.
cate, not unexpectedly, that1b and 1c deprotonated the
of 1b as the catalyst and a major singlet at 119.3 ppm hydroxy group of 7a substantiallyfaster than theydid to
for the remaining catalyst and three equal intensity lines the solvent, CD3CN or CH3CN [Eq. (2)]. Onlybyusing
centered at ꢀ10.4 ppm for 1bDþ were observed in the excess of the superbase, e.g., 1.57 equivs. of 1b or 1c (Ta-
phosphorus NMR spectrum of the reaction mixture at ble 1), 7a was moderatelyisomerized and the corre-
the end of the reaction. Apparently, a sufficient concen- sponding product was isolated in 36% and 42% yield, re-
ꢀ
tration of the catalyst is necessary during the reaction, spectively. That the CH2CN anion initiates these iso-
that is, continuous generation of the catalytic species merization is shown bythe virtual absence of these
ꢀCH2CN anion as shown in Eq. (1), is necessaryfor a
transformations in other solvents such as benzene, tol-
complete isomerization. With less than 1.0 equiv. of 1b uene, and THF. It should be noted that the electron-do-
or 1c, 2-hydroxyallylbenzene (7a), could not be isomer- nating substituent(s) in 4a–6a and 2-phenolate anion
ized under the reaction conditions. The 31P NMR meas- from 7a remarkablydecreased the conjugation rates as
urement of the reaction mixture in CD3CN revealed compared with that of 3a, presumablybecause of reduc-
onlya singlet at d(P ¼ ꢀ9.9 ppm characteristic of 2b tion in acidityof the methylene proton in the allyl groups
ꢀ
H)
or 2c, suggesting deprotonation of the phenolic OH of 4a–7a (Table 1). In all cases listed in Table 1, cis-1-ar-
group in 7a to form species A [Eq. (2)]. This deprotona- ylpropenes were formed as the minor products and the
tion process ended up within one hour. 31P NMR meas- superbase 1c exhibited higher catalytic activity than 1b.
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Table 2. Conjugation of allyl phenyl sulfide, allyl phenyl sulfone and conjugation of compounds containing CH2-interrupted
carbon-carbon double bonds.[a]
Substrate
Base (equiv)
Time [h][b]
Eluent ratio[c]
Product
Yield[d] [%] (isomer ratio)
8a
8a
9b
9a
1b (0.1)
1c (0.1)
1b (0.025)
1c (0.025)
15
A (15: 1)
A (15: 1)
A (1: 1)
A (1: 1)
93.0 (E/Z, 48/52)
95.5 (E/Z, 48/52)
96.3
13
15[e]
15[e]
95.0
10a
1b (0.8)
36[f]
A (1: 1)
40.5 (10b/10c,1/1)
10a
11a
1c (0.8)
1b (0.3)
49[g]
65
A (1: 1)
B (10: 1)
10bþ10c
11bþ11c
12bþ12c
11bþ11c
44.0 (1/1)
97.0 (11b/11c, 1/1)
11a
12a
1c (0.2)
1b (0.4)
65
120
B (10: 1)
A (10: 1)
97.1 (1/1)
50.0 (12b/12c, 1/1)
12a
13a
1c (0.4)
1b (0.3)
120
80
A (10: 1)
B (10: 1)
93.2 (1/1)
96.4 (11b/11c, 1/1)
13a
13a
1c (0.2)
1c (0.2)
66
B (10: 1)
B (10: 1)
96.9 (1/1)
38.2 (13b/13c, 1/1)
48[h]
47.8 (11b/11c, 1/1)
6.6 (11a)
[a]
Reaction conditions : 0.1 MPa, 408C; CH3CN, 5 mL; substrate, 1.0 mmol.
The conversion is 100% unless stated otherwise.
A¼n-hexane/EtOAc, B¼n-hexane/THF.
Isolated yields by TLC or column chromatography on silica gel.
At 238C.
Mass recovery, 97.2%.
Mass recovery, 95.6%.
Conversion of 13a is 97.0%.
[b]
[c]
[d]
[e]
[f]
[g]
[h]
Allyl phenyl sulfide (8a) was isomerized to 1-phenyl- benzyl allyl sulfide could not be isomerized under the
thiopropene, i.e., (E/Z)-6b in 93% yield using 1b and same conditions. An attempt to isomerize allyl phenyl
in 95.5% yield using 1c as the catalyst with an E/Z ratio ether with 1b or 1c did not succeed either. Although
close to 1.0, respectively(Table 2). The phenlythio
group obviouslyactivates the allylic methylene group
1b and 1c are capable of desulfurizing a varietyof organ-
ic sulfides,[39] theyshowed no reactivityto 8a,b. Allyl
in 8a because methyl allyl sulfide, diallyl sulfide, and phenyl sulfone (9a) was efficientlydimerized in
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Proazaphosphatrane P(RNCH2CH2)3N (R¼Me, i-Pr)-Catalyzed Isomerizations
FULL PAPERS
CH3CN bymeans of 2.5 mol % of 1b or 1c as the catalyst bysubjecting the solution of 1b or 1c in CH3OH to the
and an isomerization/dimerization product was isolated reaction conditions. Six days later 31P NMR determina-
in >95% yields. No reaction occurred with 9a in the ab- tion of the reaction mixture still revealed the presence of
sence of a protic solvent such as CH3CN under the reac- the superbase in CH3OH. In the presence of 3.0 equivs.
tion conditions, which suggests that the superbase itself of water 1b survived in CD3CN at 408C for 3 days. Some-
does not deprotonate the sulfone to initiate the reaction. how, the methyl ether of 11a, i.e., 12a, underwent the
Conjugation of methyl linoleate (10a) in CH3CN at conjugation much less efficientlythan 11a did (Table 2),
408C using the superbase catalysts only afforded the cor- and the corresponding conjugate ether isomers 12b/12c
responding products 10b and 10c (10b/10c¼1/1) in 40– (1:1) were onlyobtained in 93% yield over a period of 5
44% yields (Table 2). The isomer ratio was determined days and unreacted 12a was recovered. The superbase
byGC-MS. About 14% destruction of the ester group
catalysts exhibited much higher activity than n-BuLi
which metalated and isomerized 11a and 12a in n-hex-
ane or Et2O in up to 75% yield.[40] The TMS ether
¼
was observed to form RCH2C( O)CH2CN byattack
of the ꢀCH2CN anion generated in situ bythe catalyst
on the ester group according to the 1H NMR measure- (TMS¼trimethylsilyl) of 11a, i.e., 13a, was unexpected-
ment of the isolated product. Proton NMR monitored lyconjugated/desilylated to equivalent amounts of 11b
reactions of 10a catalyzed by 1b or 1c in CD3CN at am- and 11c in >96% yields with complete conversion of
bient temperature or 408C revealed that fast H-D ex- the TMS ether (Table 2). A shorter reaction time led
change between the a-CH2 group to the ester group to an incomplete conversion of 13a (94.6% conversion
and CD3CN/ꢀCD2CN led to deuterated methyl lino- using 1c as the catalyst over a period of 48 hours).
leate (RCH2CD2COOMe, D) from which a fast equili- From the above incomplete reaction of 13a, the corre-
brium was established as shown in Scheme 3. In CH3 sponding conjugated TMS ethers, i.e., 13b and 13c
CN such an equilibrium consumed a considerable (1:1), isomerization–desilylation products 11b and
amount of anion ꢀCH2CN generated bythe superbase
catalyst and thus lessened the deprotonation of 11- in 38.2%, 47.8%, and 6.6% yields, respectively (Ta-
CH2 in 10a, remarkablydecreasing the conjugation rates
ble 2). These results have demonstrated that ꢀCH2CN
11c (1:1), and the desilylated alcohol 11a were isolated
and efficiency. Unexpectedly, cis,cis-9,12-octadecadie- anions generated bythe superbase catalysts not onlyin-
nol (11a) was isomerized to its corresponding conjugate itiated conjugation of CH2-interrupted carbon-carbon
alcohols 11b and 11c (11b/11c¼1.0) in CH3CN at 408C double bonds but also desilylated the silyl ether to
in 97% yield by using 1b or 1c as the catalyst (Table 2). form the alcohol.[41] A conjugation-desilylation/desilyla-
The conjugation reaction of 11a was carried out in tion-conjugation mechanism is proposed to explain the
CD3CN at 408C using 1b or 1c as the catalyst and was reactions of 13a in CH3CN using 1b or 1c as the catalyst
monitored by 31P NMR measurements. The following (Scheme 4). It is clear that the conjugated silyl ethers
results were observed. Considerable amounts of the su- 12b/12c and the desilylated alcohol 11a were the reac-
perbase catalyst survived during the reaction (singlet, tion intermediates. Under the same conditions 1c
dP: 119.4 ppm for 1b; 118.2 ppm for 1c) and the catalyst showed higher catalytic activity than 1b for all the reac-
was predominantlytransformed into its deuterated
tions and a reactivityorder 11a>13a>12a>10a was
form, i.e., B [three equal intensitylines centered at
observed.
d(P D): ꢀ10.4 ppm for 1bDþ and ꢀ11.2 ppm for 1cDþ]
ꢀ
and onlydetectable amounts of the protonated form,
i.e., 2b or 2c, were observed [singlet, d(P H): ꢀ10.0 ppm
ꢀ
Conclusions
for 2b; ꢀ10.1 ppm for 2c].
These results reveal that both superbases 1b and 1c de-
protonated the hydroxy group of 11a and its correspond-
ing conjugate alcohols veryslowly, and theypredomi-
nantlydedeuterated (or deprotonated) the solvent
CD3CN (or CH3CN) to generate ꢀCD2CN (or
ꢀCH2CN) anions to initiate the conjugation reaction.
Such a slow deprotonation of alcohol was confirmed
An efficient approach to isomerize allylaromatics, allyl
sulfide, allyl sulfone, and CH2-interrupted carbon-car-
bon double bonds-containing compounds bythe non-
ionic proazaphosphatrane catalysts P(RNCH2CH2)3N
(R¼Me, i-Pr) was achieved under mild conditions.
The high yields and selectivities for propenylaromatics
and long-chain cis,trans-conjugated diene derivatives
offer promising alternative routes to these compounds
in organic synthesis.
Experimental Section
All the reactions and solvent treatments were carried out un-
der a nitrogen or argon atmosphere. Acetonitrile was distilled
over calcium hydride. Compound 8a was prepared as re-
Scheme 3.
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Zhengkun Yu et al.
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Scheme 4.
ported,[22a] 11a (from TCI America Co.) and other chemicals
were used as received.
reduced pressure. Distillation at 1308C/0.68 torr afforded 13a
as a colorless liquid; yield: 8.4 g (89.3%); 1H NMR (400 MHz,
¼
238C, CDCl3): d¼5.33 (m, 4H, 2 CH CH), 3.54 (t, 2H,
OCH2), 2.75 (t, 2H, 11-H), 2.03 (m, 4H, CH2), 1.31 (m, 2H,
CH2), 1.27 (m and broad, 16H, 8 CH2), 0.87 (t, 3H, CH3), 0.08
[s, 9H, Si(CH3)3]; 13C{1H} NMR (400 MHz, 238C, CDCl3):
d¼130.2 and 128.0, 62.7, 32.7, 31.5, 29.7, 29.6, 29.5, 29.4, 29.3,
27.2, 25.8. 25.6, 22.6, 14.1 (CH3), ꢀ0.4 [Si(CH3)3]; anal. calcd.
for C21H42OSi: C 74.49, H 12.51; found: C 74.30, H 12.45.
General Procedure for 1b- and 1c-Catalyzed
Isomerization or Conjugation
In a 25-mL flask was dissolved a catalytic amount of 1b or 1c in
5.0 mL of dryacetonotrile. To this mixture was added 1.0 mmol
of the substrate and the mixture was stirred at 408C. The reac-
tion time was approximatelythe same as that necessaryfor
completion of the same reaction on a 0.1–0.2 mmol scale of
the substrate in CD3CN (0.7 mL) in a 5-mm NMR tube under
the same reaction conditions. After the reaction mixture had
been stirred for the stated time, the reaction mixture was con-
centrated under reduced pressure and isolated bycolumn chro-
matographyor TLC on silica gel. The products were subject to
NMR and GC-MS analyses, and >98% NMR puritywas ob-
tained for all the products.
Acknowledgements
We are grateful to the “Hundred Talented Program” Funding of
Chinese Academy of Sciences for support of this research, and
thank Professor Dr. J. G. Verkade and Dr. WeipingSu for their
kind suggestions and helpful discussion.
References and Notes
Preparation of 12a
To a mixture of 11a (0.815 g, 3.0 mmol) and CH3I (0.45 g,
3.2 mmol) in 10 mL of DMSO, 1.50 g of KOH was added and
the mixture was stirred at ambient temperature for 30 minutes.
100 mL of water were then added and the mixture was extract-
ed with EtOAc (3ꢁ40 mL). The organic layer was dried over
MgSO4, filtered and all the volatiles evaporated under reduced
pressure. Isolation bycolumn chromatographyon silica gel
with n-hexane/EtOAc (15:1) afforded 12a as a colorless liquid;
yield: 0.538 g (64%).
[1] a) A. Shimizu, T. Otsu, M. Imoto, Bull. Chem. Soc. Jpn.
1968, 41, 953; b) J. Blum, Y. Pickholtz, Isr. J. Chem. 1969,
7, 723.
[2] a) B. I. Cruikshank, N. R. Davies, Aust. J. Chem. 1973,
26, 2635; b) Y. Sasson, A. Zoran, J. Blum, J. Mol. Catal.
1981, 11, 293.
[3] a) A. Zoran, Y. Sasson, J. Org. Chem. 1981, 46, 255;
b) Jr., E. O. Sherman, M. Olson, J. Organomet. Chem.
1979, 172, C13.
[4] a) G. A. Devora, M. P. Doyle, Main Group Met. Chem.
´
ˆ
1994, 17, 395; b) L. Kollar, E. Farkas, J. Batiu, J. Mol.
Catal. 1997, 115, 283; c) H. Alper, K. Hachem, Transition
Met. Chem. 1981, 6, 219.
Preparation of 13a
To a stirred mixture of 11a (7.40 g, 27.7 mmol) and trimethylsil-
yl chloride (3.32 g, 30.4 mmol) in THFat 08C, 3.64 g (36 mmol)
of Et3N were added. After the reaction was complete within 3
hours, 150 mL of water were added and the mixture was ex-
tracted with CH2Cl2 (3ꢁ100 mL). The organic layer was dried
over MgSO4, filtered, and all the volatiles were removed under
[5] H. Bricout, A. Mortreux, E. Monflier, J. Organomet.
Chem. 1998, 553, 469.
[6] a) N. Satyanarayana, M. Periasamy, J. Organomet. Chem.
1987, 319, 113; b) W. E. McCormack, M. E. Orchin, J.
Organomet. Chem. 1977, 129, 127.
116
asc.wiley-vch.de
ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2006, 348, 111 – 117

Proazaphosphatrane P(RNCH2CH2)3N (R¼Me, i-Pr)-Catalyzed Isomerizations
FULL PAPERS
[7] a) P. A. Tooley, L. W. Arndt, M. Y. Darensberg, J. Am.
Chem. Soc. 1985, 107, 2422; b) M. R. Reddy, M. Periasa-
my, J. Organomet. Chem. 1995, 491, 263.
[8] a) Y. Qian, G. Li, X. Zheng, Y. Huang, J. Mol. Catal.
1993, 78, L31; b) G. Li, Y. Qian, Y. Huang, J. Mol. Catal.
1992, 72, L15; c) S. A. Rao, M. Periasamy, J. Organomet.
Chem. 1988, 342, 15; d) C. Averbuj, M. S. Eisen, J. Am.
Chem. Soc. 1999, 121, 8755.
tino, L. Perrotta, L. Landi, Q. G. Mulazzani, C. Chatgilia-
loglu, J. Am. Chem. Soc. 2001, 123, 4459.
[27] a) A. Basu, S. Bhaduri, T. G. K. Kasar, Eur. Pat. Appl.
EP 85–302982, 1985, ; Chem. Abstr. 1986, 104, 209140;
b) V. M. Deshpande, R. G. Gadkari, D. Mukesh, C. S.
Narasimhan, J. Am. Oil Chem. Soc. 1985, 62, 734; c) A.
Basu, K. R. Sharma, J. Mol. Catal. 1986, 38, 315; d) D.
Mukesh, C. S. Narasimhan, V. M. Deshpande, K. Ram-
narayan, Ind. Eng. Chem. Res. 1988, 27, 409; e) P. Pertici,
V. Ballantini, S. Catalano, A. Giuntoli, C. Malanga, G.
Vitulli, J. Mol. Catal. A: Chem. 1999, 144, 7.
[9] a) J. Schwartz, M. D. Ward, J. Mol. Catal. 1980, 8, 465;
b) C. Lau, B. Chang, R. H. Grubbs, Jr., C. H. Brubaker,
J. Organomet. Chem. 1981, 214, 325.
[10] C. Qian, D. Zhu, D. Li, J. Organomet. Chem. 1992, 430,
175.
[28] T. L. Mounts, H. J. Dutton, D. N. Glover, Lipids 1970, 5,
997.
[11] A. J. Birch, G. S. R. Subba Rao, Tetrahedron Lett. 1968,
9, 3797.
[29] P. Van der Plank, H. J. Van Oosten, J. Am. Oil Chem.
Soc. 1979, 56, 54.
[12] D. V. Sokolskii, N. P. Trukhachova, React. Kinet. Catal.
Lett. 1981, 17, 393.
[13] H. Pines, W. M. Stalick, Base-Catalyzed Reactions of Hy-
drocarbons and Related Compounds, Academic Press
Inc., New York, 1977.
[30] a) S. Adhikari, H. Sprinz, O. Brede, Res. Chem. Interm.
2001, 27, 549; b) J. Schwinn, H. Sprinz, K. Drossler, S.
Leistner, O. Brede, Int. J. Rad. Bio. 1998, 74, 359.
[31] G. G. Abbot, F. D. Gunstone, S. D. Hoyes, Chem. Phys.
Lipids 1970, 4, 351.
[14] A. S. Radhakrishna, S. K. Suri, R. Prasad, K. R. K. Rao,
K. Sivaprakash, B. B. Singh, Synth. Commun. 1990, 20,
345.
[32] a) R. Canaguier, J. L. Chevalier, G. Cecchi, E. Ucciani,
Rev.Fr. Corps Gras 1986, 33, 157; b) K. Seki, R. Kaneko,
M. Kataoka, Yukagaku 1991, 40, 507.
[15] L. N. Thach, D. Hanh, N. B. Hiep, A. S. Radhakrishna,
B. B. Singh, A. Loupy, Synth. Commun. 1993, 23, 1379.
[16] M. Hassan, N. A. R. O. Abdel, A. M. Satti, K. S. Kirollos,
Int. J. Chem. Kinet. 1982, 14, 351.
[17] R. Neumann, Y. Sasson, J. Mol. Catal. 1985, 33, 201.
[18] J. Schwartz, M. D. Ward, J. Org. Chem. 1984, 49, 3448.
[19] a) M. Halpern, M. Yonowich-Weiss, Y. Sasson, M. Rabi-
novitz, Tetrahedron Lett. 1981, 22, 703; b) M. Halpern, Y.
Sasson, M. Rabinovitz, J. Org. Chem. 1983, 48, 1022.
[20] G. V. Salmoria, E. L. DallꢀOglio, C. Zucco, Synth. Com-
mun. 1997, 27, 4335.
[33] a) H. Schmidt, C. Lensink, S. K. Xi, J. G. Verkade, Z.
Anorg. Allg. Chem. 1989, 75, 578; b) J. G. Verkade, Co-
ord. Chem. Rev. 1994, 137, 233; c) B. A. DꢀSa, P. B. Ki-
sanga, D. Mcleod, J. G. Verkade, Phosphorus, Silicon
and Sulfur 1997, 124, 233; d) B. A. DꢀSa, P. B. Kisanga,
J. G. Verkade, J. Org. Chem. 1998, 63, 3961.
[34] For recent reviews and selected papers on Verkade su-
perbases, see: a) J. G. Verkade, Top. Curr. Chem. 2002,
233, 1; b) P. B. Kisanga, J. G. Verkade, Tetrahedron
2003, 59, 7819; c) J. G. Verkade, P. B. Kisanga, Aldrichi-
mica Acta 2004, 37, 3; d) W. P. Su, S. Urgaonkar, P. A.
McLaughlin, J. G. Verkade, J. Am. Chem. Soc. 2004,
126, 16433; e) S. Urgaonkar, J. G. Verkade, J. Org.
Chem. 2004, 69, 5752; f) W. P. Su, S. Urgaonkar, J. G. Ver-
kade, Org. Lett. 2004, 6, 1421.
[21] S. Suzuki, M. Kato, S. Nakajima, Can. J. Chem. 1994, 72,
357.
[22] a) D. S. Tarbell, M. A. McCall, J. Am. Chem. Soc. 1952,
74, 48; b) I. Sataty, C. Y. Meyers, Tetrahedron Lett.
1974, 4161; c) K. Osakada, T. Chiba, Y. Nakamura, T. Ya-
mamoto, A. Yamamoto, Organometallics 1989, 8, 2602;
d) K. Stanislaw, S. Jerzy, Pol. J. Chem. 1990, 64, 505.
[23] G. Karimov, V. S. Aksenov, S. D. Usmanova, B. I. Gizato-
va, I. U. Numanov, Dokl. Akad. Nauk Tadzh. SSSR 1983,
26, 776; Chem. Abstr. 1984, 101, 171012.
[24] W. E. Truce, T. C. Klinger, W. W. Brand, in: Organic
Chemistry of Sulfur, (Ed.: S. Oae), Plenum Press, New
York, 1977, pp. 527–602 and references cited therein.
[25] W. Wu, J. G. Verkade, Arkivoc 2004, 9, 88.
[26] a) A. Basu, S. Bhaduri, K. R. Sharma, Adv. Catal. 1985,
7, 669; b) A. Basu, T. G. Kasar, J. Am. Oil Chem. Soc.
1986, 63, 1444; c) C. S. Narashimhan, K. Ramnarayan,
V. M. Deshpande, J. Mol. Catal. 1989, 52, 305; d) J.
Schwinn, H. Sprinz, K. Drossler, S. Leistner, O. Brede,
Int. J. Radiat. Biol. 1998, 74, 359; e) C. Ferreri, C. Costan-
[35] a) J. S. Tang, J. G. Verkade, Angew. Chem. Int. Ed. Engl.
´
1993, 32, 896; b) A. Wroblewski, J. Pinkas, J. G. Verkade,
Main Group Chem. 1995, 1, 69; c) P. B. Kisanga, J. G.
Verkade, R. Schwesinger, J. Org. Chem. 2000, 65, 5431.
[36] a) S. Arumugam, D. Mcleod, J. G. Verkade, J. Org.
Chem. 1997, 62, 4827; b) S. Arumugam, D. McLeod,
J. G. Verkade, J. Org. Chem. 1998, 63, 3677; c) P. B. Ki-
sanga, J. G. Verkade, J. Org. Chem. 1999, 64, 4298;
d) B. A. DꢀSa, P. B. Kisanga, J. G. Verkade, J. Org.
Chem. 1998, 63, 3961.
[37] Z. K. Yu, J. G. Verkade, Adv. Synth. Catal. 2004, 346, 539.
[38] J. S. Tang, J. G. Verkade, J. Am. Chem. Soc. 1993, 115,
1660.
[39] Z. K. Yu, J. G. Verkade, Heteroatom Chem. 1999, 10, 544.
[40] J. Klein, S. Glily, D. Kost, J. Org. Chem. 1970, 35, 1281.
[41] Z. K. Yu, J. G. Verkade, J. Org. Chem. 2000, 65, 2065.
Adv. Synth. Catal. 2006, 348, 111 – 117
ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
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