Preparation of organomanganese reagents from organic halides with activated manganese

Article abstract of DOI:10.1016/S0040-4020(01)00864-X

Reduction of Li₂MnCl₄ with magnesium metal provided activated manganese as a black suspension in THF. Treatment of organic halides such as allyl bromides, α-halo esters or aryl halides with activated manganese furnished various organomanganese reagents which reacted further with electrophiles to afford the corresponding adducts. The reaction of a ketone bearing an iodoaryl moiety with this active manganese induced cyclization to provide dihydroindene derivative.

Full text of DOI:10.1016/S0040-4020(01)00864-X

TETRAHEDRON
Pergamon
Tetrahedron 57 ;2001) 8807±8815
Preparation of organomanganese reagents from organic halides
with activated manganese
Hirotada Kakiya, Shinji Nishimae, Hiroshi Shinokubo and Koichiro Oshimap
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
Received 25 July 2001;accepted 22 August 2001
AbstractÐReduction of Li2MnCl4 with magnesium metal provided activated manganese as a black suspension in THF. Treatment of
organic halides such as allyl bromides, a-halo esters or aryl halides with activated manganese furnished various organomanganese reagents
which reacted further with electrophiles to afford the corresponding adducts. The reaction of a ketone bearing an iodoaryl moiety with this
active manganese induced cyclization to provide dihydroindene derivative. q 2001 Elsevier Science Ltd. All rights reserved.
1. Introduction
2. Results and discussion
In 1936, H. Gillman and J. Bailie prepared diphenyl-
manganese and phenylmanganese iodide, which were the
®rst organomanganese compounds synthesized. However,
organomanganese chemistry had been mainly unexplored
until J. F. Normant and G. Cahiez started studies on the
preparation of organomanganese reagents and synthetic
applications of these compounds.1 Recently the studies of
synthetic reactions using organomanganese reagents have
been undertaken by several groups and ours.2 Organo-
manganese compounds have proved to be useful reagents
with high chemoselectivity for selective C±C bond forma-
tion. The organomanganese reagents are typically prepared
via transmetalation of manganese salts with organolithiums
or Grignard reagents. However, it is dif®cult to prepare the
functionalized organomanganese reagents through the
transmetalation protocol due to the dif®culty in preparation
of functionalized organolithiums or Grignard reagents. On
the other hand, the direct preparation of the organo-
manganese reagents from organic halides with activated or
non-activated manganese have been reported recently.3,4
Among various methods, we have reported that the reduc-
tion of an ate-complex Li2MnCl4 with magnesium metal in
THF afforded a black suspension of activated manganese5
which initiated radical cyclization of allyl b-iodoacetals at
room temperature.6 In this paper, we wish to describe the
reactivity of organomanganese reagents which were gener-
ated from activated manganese and organic halides such as
allylic halides, a-halo esters, or aryl halides. The cyclization
of a ketone bearing an iodoaryl moiety is also reported.
2.1. Activated manganese-induced reaction of allylic
bromides with carbonyl compounds
A pale yellow±green THF solution of Li2MnCl4, derived
from 1.0 equiv. of MnCl2 and 2.0 equiv. of LiCl, was
added to the magnesium turnings activated by 1,2-dibromo-
ethane. The resulting mixture was stirred for 24 h at room
temperature to provide a black suspension of activated
manganese. The suspension of activated manganese was
introduced to a THF±hexane solution of allyl bromide
;1a) and benzaldehyde ;2a) at 2428C under argon
atmosphere. Then, the mixture was warmed up to 258C
to provide 1-phenyl-3-buten-1-ol ;3a) in 82% yield
;Scheme 1).7
Scheme 1.
The results of the reaction of various allylic bromides with
carbonyl compounds are shown in Table 1. Several
comments are worth noting. ;1) The reaction of aliphatic
aldehydes such as decanal ;2b) and cyclohexanecarbalde-
hyde ;2c) afforded the corresponding allylated products as
well as aromatic aldehyde ;entries 2 and 3). ;2) The use of
ketones ;acetophenone ;2d) and cyclohexanone ;2e)) in
place of aldehydes also provided the corresponding homo-
allylic alcohols ;entries 4 and 5). ;3) The reaction of crotyl
bromide ;1b) afforded a regioisomeric mixture of a-adduct
3f and g-adduct 4f in 32% and 14% yield, respectively. ;4)
In the case of cinnamyl bromide ;1c), 3,4-diphenyl-1,5-
hexadiene, 1,6-diphenyl-1,5-hexadiene, and 1,4-diphenyl-
Keywords: manganese and compounds;alkyl halides;Reformatsky
reactions/reagents;cyclization.
p
Corresponding author. Tel.: 181-75753-5523;fax: 181-75753-4863;
e-mail: oshima@fm1.kuic.kyoto-u.ac.jp
0040±4020/01/$ - see front matter q 2001 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020;01)00864-X

8808
H. Kakiya et al. / Tetrahedron 57 ,2001) 8807±8815
Table 1. Allylation of carbonyl compounds via the activated manganese
Entry
1
2
Yield ;%)a
R1
R2
R3
3
4
1
H ;1a)
H ;1a)
H ;1a)
H ;1a)
H ;1a)
Me ;1b)
Ph ;1c)
Ph
H ;2a)
H ;2b)
H ;2c)
Me ;2d)
;2e)
82 ;3a)
47 ;3b)
52 ;3c)
37 ;3d)
47 ;3e)
32 ;3f)d
30 ;3g)g
2
n-C9H19
c-C6H11
Ph
±;CH2)5±
Ph
Ph
3b
4
5
6c
7f
H ;2a)
H ;2a)
14 ;4f)e
9 ;4g)h
The reactions were performed with 1 ;1.0 mmol), 2 ;2.0 mmol) and Mnp ;3.0 mmol).
Yields are based on 1.
a
b
c-C6H11ˆcyclohexyl.
c
A mixture ;88/12) of 1-bromo-2-butene ;E/Zˆ84/16) and 3-bromo-1-butene was used.
d
E/Zˆ75/25.
e
erythro/theroˆ44/56.
f
The coupling products of cinnamyl bromide, 3,4-diphenyl-1,5-hexadiene ;7%), 1,6-diphenyl-1,5-hexadiene ;21%), and 1,4-diphenyl-1,5-hexadiene ;23%)
were also obtained.
E only.
g
h
erythro/threoˆ50/50.
Scheme 2.
Scheme 4.
1,5-hexadiene were formed as by-products in addition to the
desired allylated products 3g and 4g.
with 10a ;55%). The treatment of a-bromo ester 8c
provided 10a in good yield ;Scheme 4).
The reaction of benzyl bromide with benzaldehyde provided
the corresponding benzylated product 6 in 41% yield
;Scheme 2).
The results of the reaction of a-halo esters with various
carbonyl compounds are summarized in Table 2. Several
issues regarding the results in Table 2 merit comments.
;1) The reactivity of benzyl 2-bromo-2-methylpropanoate
;16) was similar to that of benzyl 2-iodopropanoate ;8a).
;2) The use of aliphatic aldehydes provided the correspond-
ing adducts in good yields ;entries 1±3, 8, 9). ;3) Ketones
were as reactive as aldehydes and afforded the Reformatsky-
type products effectively ;entries 4, 5, and 10). ;4) a,b-
Unsaturated carbonyl compounds reacted in a 1,2-manner
exclusively. No 1,4-addition products were detected in the
reaction mixture ;entries 3, 5, and 9). ;5) The reactions of
acyl chloride proceeded effectively to afford the b-keto ester
;entries 6 and 11).
2.2. Activated manganese-mediated reaction of a-halo
carbonyl compounds with aldehydes
We next picked up a-halo esters as reactive organic halides.
Treatment of a mixture of benzyl 2-iodoacetate ;7) and
benzaldehyde ;2a) with suspension of activated manganese
at 258C afforded a Reformatsky-type adduct, b-hydroxy
ester 9a, in 58% yield.8 The reaction of benzyl 2-iodo-
propanoate ;8a) in place of benzyl 2-iodoacetate ;7)
provided the corresponding adduct 10a in 78% yield
;Scheme 3).
The reaction of a-chloro ester 8b or a-bromo ester 8c
instead of a-iodo ester was examined. In the case of 8b,
the starting material 8b was recovered in 34% yield along
To reveal the reaction mechanism, we carried out the
reaction of 7 with activated manganese in the presence of
methanol-d ;Scheme 5).
The deuterium incorporation in 12-d clearly suggested the
generation of enolate 14 as an intermediate.9,10 On the basis
of this fact, we propose the following reaction mechanism
;Scheme 6).
The reaction of a-halo lactones or a-halo amides instead of
Scheme 3.

H. Kakiya et al. / Tetrahedron 57 ,2001) 8807±8815
8809
Table 2. The reaction of a-iodo or a-bromo ester
Entry
Ester
2
Time ;h)
Yield ;%)a
erythro/threo
X
R1
R2
n-C6H13
i-Pr
R3
1
2
I
I
H ;8a)
H ;8a)
H ;2f)
H ;2g)
18.5
15.5
79 ;10b)
78 ;10c)
52/48
51/49
3b
I
H ;8a)
H ;2h)
17.5
94 ;10d)
41/59
4
I
I
I
Br
Br
H ;8a)
H ;8a)
H ;8a)
Me ;16)
Me ;16)
Me
2-cyclohexenone
Ph
Ph
Me ;2i)
;2j)
Cl ;2k)
H ;2a)
H ;2g)
17.5
15
17
18
93 ;10e)
59 ;10f)
67 ;11a)
84 ;17a)
80 ;17b)
5b
6c
7
55/45
8
i-Pr
19.5
9b
Br
Me ;16)
H ;2h)
20.5
84 ;17c)
10
11d
Br
Br
Me ;16)
Me ;16)
Me
Me
Me ;2i)
Cl ;2l)
17
16.5
91 ;17d)
84 ;18a)
Reactions were performed with benzyl ester ;0.5 mmol), 2 ;0.6 mmol) and Mnp ;1.0 mmol) in THF at 258C.
Yields are based on benzyl ester.
a
b
Only 1,2-adduct was obtained and 1,4-adduct was not detected.
The product was benzyl 2-methyl-3-oxo-3-phenylpropanoate ;11a).
The product was benzyl 2,2-dimethyl-3-oxobutanoate ;18a).
c
d
a-halo esters with various electrophiles proceeded
ef®ciently to provide the corresponding adducts. Tables 3
and 4 show the results of the reaction of a-iodo lactones and
a-iodo amides, respectively. In both reactions of a-iodo
lactones and a-iodo amides, aldehydes or ketones were
effective as electrophiles. In contrast, benzoyl chloride
was less effective as an electrophile. The use of a-iodo
ketone 25 as an a-halo carbonyl compound gave a
Scheme 5.
Scheme 6.
Table 3. The reaction of a-iodo lactone
Entry
2
Time ;h)
Yield ;%)a
erythro/threo
R1
R2
1
2
Ph
n-C6H13
H ;2a)
H ;2f)
1
2.5
99 ;20a)
84 ;20b)
50/40
60/40
3b
H ;2m)
Me ;2i)
Cl ;2k)
2.5
2
2
82 ;20c)
97 ;20d)
56 ;21a)
55/45
4
Me
Ph
5c
Reactions were performed with 19a ;0.5 mmol), 2 ;0.6 mmol) and Mnp ;1.0 mmol) in THF at 258C.
Yields are based on 19a.
a
b
Only 1,2-adduct was obtained and 1,4-adduct was not detected.
The product was b-keto ester 21a.
c

8810
H. Kakiya et al. / Tetrahedron 57 ,2001) 8807±8815
Table 4. The reaction of a-iodo amide
Entry
2
Time ;h)
Yield ;%)a
erythro/threo
R1
R2
1
2
Ph
H ;2a)
H ;2f)
Me ;2i)
Cl ;2k)
23.5
21
22
24.5
99 ;23a)
88 ;23b)
81 ;23c)
trace ;24a)
58/42
61/39
n-C6H13
Me
Ph
3
4b
Reactions were performed with 22a ;0.5 mmol), 2 ;0.6 mmol) and Mnp ;1.0 mmol) in THF at 258C.
Yields are based on 22a.
The product was b-keto amide 24a.
a
b
benzene ;27a) with activated manganese in THF in the
absence of benzaldehyde and found the formation of
phenylmanganese iodide. Sequential addition of benzalde-
hyde ;2a) provided diphenylmethanol ;28a) in 21% yield
;Scheme 8). The results of the reaction of various aryl
halides are shown in Table 5.
Scheme 7.
disappointing result. Treatment of 3-iodo-2-butanone ;25)
with activated manganese in the presence of benzaldehyde
;2a) provided the corresponding b-hydroxy ketone 26 in
only 21% yield ;Scheme 7).
Scheme 8.
2.3. Activated manganese-mediated reaction of aryl
halides with carbonyl compounds
Several characteristics of this reaction are noteworthy. ;1)
Compared with iodobenzene ;27a), the use of the substrate
with electron-withdrawing group such as a tri¯uoromethyl
moiety improved the yield of the desired product dramati-
cally. ;2) Aliphatic aldehyde 2f is a good electrophile for the
trapping of manganese species as well as aromatic alde-
hydes ;entry 2). ;3) Aryl bromide 27d was less reactive
than the corresponding aryl iodide 27b, and the reaction
with benzaldehyde afforded the benzylic alcohol 28 in
only 31% yield.
We next investigated the reaction of aryl halides. Treatment
of a mixture of iodobenzene ;27a) and benzaldehyde ;2a)
with activated manganese in THF provided a pinacol
coupling adduct ;hydrobenzoin) and none of the expected
product was observed in the reaction mixture. This result
indicates that the reduction of benzaldehyde proceeds much
faster than that of iodobenzene. Then we treated iodo-
Table 5. The reaction of aldehydes with arylmanganese derived from aryl
halides and activated manganese
2.4. Reaction of ketones bearing an iodoaryl moiety with
activated manganese
We found that activated manganese prepared by our pro-
cedure was less reactive toward ketones. It is hence
expected that an addition of activated manganese to a iodo-
benzene, which has alkyl substituent bearing a ketone
moiety on ortho position, would provide an arylmanganese
species 30 without the reduction of the ketone moiety. This
was indeed the case and treatment of 1-;2-iodophenyl)-
2,2,4-trimethyl-3-pentanone ;29a) with activated manga-
nese afforded the cyclization product 32a in 65% yield.
The reaction would proceed as follows: ;1) formation of
arylmanganese species 30, and ;2) subsequent cyclization
via an intramolecular addition to the carbonyl group
;Scheme 9).11
Entry
1
ArX
RCHO
Yield ;%)a
PhCHO ;2a)
72
2
3
4
n-C6H13CHO ;2f)
PhCHO ;2a)
80
59
31
PhCHO ;2a)
The use of aryl bromide 29b in place of 29a, however,
provided the desired product 32a in only 25% yield even
in re¯uxing THF, and a considerable amount of the starting
material was recovered ;Scheme 10).
Reactions were performed with aryl halide ;1.0 mmol), aldehyde
;2.0 mmol) and Mn* ;4.0 mmol) in THF.
Yield based on aldehyde.
a

H. Kakiya et al. / Tetrahedron 57 ,2001) 8807±8815
8811
Scheme 9.
4. Experimental
4.1. General
NMR spectra ;1H and 13C) were recorded on a Varian
GEMINI 300 spectrometer in CDCl3;tetramethylsilane
;TMS) was used as an internal standard. IR spectra were
determined on a SHIMADZU FTIR-8200PC spectrometer.
Mass spectra were determined on a JEOL Mstation 700
spectrometer. Silica gel ;Wakogel 200 mesh) was used for
column chromatography. The analyses were carried out at
the Elemental Analysis Center of Kyoto University. Unless
otherwise noted, materials obtained from commercial
suppliers were used without further puri®cation. Tetra-
hydrofuran ;THF) was freshly distilled from sodium benzo-
phenone ketyl before use. Anhydrous manganese;II)
chloride purchased from Aldrich was heated at 1608C for
2 h prior to use.
Scheme 10.
Other aryl iodides such as 29c and 29d also provided the
corresponding products in moderate yields upon treatment
with activated manganese. In contrast, aryl iodide 29e
having a formyl group gave a complex mixture along with
none of desired cyclization product ;Scheme 11).
4.2. Starting materials
According to literature procedures, 1-;2-bromophenyl)-
2,2,4-trimethyl-3-pentanone ;29b)11a and 3-;2-iodophenyl)-
propanal ;29e)12 were prepared. In a similar fashion,11a
1-;2-iodophenyl)-2,2,4-trimethyl-3-pentanone ;29a), 3-;2-
iodophenyl)-2,2-dimethyl-1-phenyl-1-propanone
and 1-;2-iodophenyl)-2-methyl-3-pentanone ;29d) were
;29c),
prepared.
4.3. Preparation of benzyl 2-iodopropanoate
To a solution of benzyl alcohol ;1.08 g, 10 mmol) and pyr-
idine ;0.87 g, 11 mmol) in dichloromethane ;15 mL) was
added 2-chloropropanoyl chloride ;1.40 g, 11 mmol) drop-
wise at 08C, and the mixture was warmed to room tempera-
ture over a period of 4 h. The reaction was quenched with
water and the reaction mixture was extracted with ethyl
acetate. The combined organic layers were dried over
Na2SO4 and concentrated in vacuo to provide the benzyl
2-chloropropanoate. Sodium iodide ;3.00 g, 20 mmol) was
added to the crude product ;1.97 g, 9.9 mmol) in acetone
;10 mL) and the mixture was stirred for 12 h at 258C. Usual
workup followed by silica gel column chromatography
afforded benzyl 2-iodopropanoate ;2.81 g, 9.7 mmol) in
97% yield.
Scheme 11.
3. Conclusions
We found that activated manganese, prepared by the
reduction of Li2MnCl4 with magnesium metal, was effective
for the direct preparation of various organic manganese
reagents from organic halides. Various allylic halides
could be converted into the corresponding allylic
manganese upon treatment with activated manganese.
Treatment of a-halo carbonyl compounds such as a-halo
esters, a-halo lactones, a-halo amides, or a-halo ketones
provided manganese enolates, which reacted with electro-
philes to afford the corresponding products in good yield.
One can also prepare arylmanganese compounds by the
reduction of aryl iodides with activated manganese. Further-
more, activated manganese induced cyclization of aryl
halides bearing a ketone moiety to provide the 2,3-
dihydroinden-1-ol derivatives.
4.3.1. 1-/2-Iodophenyl)-2,2,4-trimethyl-3-pentanone /29a).
Mp 518C;IR ;nujol) 2963, 1692, 1366, 1015, 750 cm 21; 1H
NMR ;CDCl3) d 1.07 ;d, Jˆ6.6 Hz, 6H), 1.20 ;s, 6H), 3.11
;s, 2H), 3.20 ;sept, Jˆ6.6 Hz, 1H), 6.89 ;dt, Jˆ1.8, 7.8 Hz,
1H), 7.16 ;dd, Jˆ1.8, 7.8 Hz, 1H), 7.25 ;dt, Jˆ1.2, 7.8 Hz,
1H), 7.85 ;dd, Jˆ1.2, 7.8 Hz, 1H); 13C NMR ;CDCl3) d
19.99, 23.71, 34.30, 46.43, 49.92, 103.41, 128.00, 128.18,

8812
H. Kakiya et al. / Tetrahedron 57 ,2001) 8807±8815
130.97, 140.03, 141.53, 219.81. Found: C, 50.64;H, 5.63%.
Calcd for C14H19IO: C, 50.92;H, 5.80%.
;3d),16 1-allylcyclohexanol ;3e),15 1-phenyl-3-penten-1-ol
;3f),17 2-methyl-1-phenyl-3-buten-1-ol ;4f),18 1,4-di-
phenyl-3-buten-1-ol ;3g),17 1,2-diphenyl-3-buten-1-ol
;4g),19,20 1,2-diphenylethanol ;6),21 3,4-diphenyl-1,5-hexa-
diene,22 1,6-diphenyl-1,5-hexadiene,23 and 1,4-diphenyl-
1,5-hexadiene24 were identical with those reported in
literatures.
4.3.2. 3-/2-Iodophenyl)-2,2-dimethyl-1-phenyl-1-propa-
none /29c). IR ;neat) 3059, 2970, 2931, 1674, 1597,
1579, 1463, 1444, 1388, 1261, 1011, 959, 752, 729,
1
700 cm21; H NMR ;CDCl3) d 1.37 ;s, 6H), 3.36 ;s, 2H),
6.89 ;dt, Jˆ1.8, 7.5 Hz, 1H), 7.14 ;dd, Jˆ1.8, 7.5 Hz, 1H),
7.22 ;dt, Jˆ1.5, 7.5 Hz, 1H), 7.36±7.50 ;m, 3H), 7.60±7.66
;m, 2H), 7.86 ;dd, Jˆ1.5, 7.5 Hz, 1H); 13C NMR ;CDCl3) d
25.97, 48.41, 49.68, 103.31, 127.74, 128.10, 128.21, 128.28,
130.76, 130.89, 139.22, 140.09, 141.51, 209.56. HRMS
Found: m/z 364.0342. Calcd for C17H17IO: M, 364.0324.
4.5.1. 1-Tridecen-4-ol /3b). IR ;neat) 3348, 2925, 2856,
1
1712, 1466, 1441, 995, 912 cm21; H NMR ;CDCl3) d
0.88 ;t, Jˆ6.6 Hz, 3H), 1.20±1.53 ;m, 17H), 2.07±2.21
;m, 1H), 2.26±2.38 ;m, 1H), 3.60±3.70 ;m, 1H), 5.09±
5.20 ;m, 2H), 5.78±5.91 ;m, 1H); 13C NMR ;CDCl3) d
19.38, 22.57, 25.56, 29.22, 29.47, 29.52, 29.56, 31.81,
36.74, 41.85, 70.70, 118.10, 135.01. HRMS Found: m/z
198.1992. Calcd for C13H26O: M, 198.1984.
4.3.3. 1-/2-Iodophenyl)-2-methyl-3-pentanone /29d). IR
;neat) 2972, 2936, 2876, 1713, 1562, 1462, 1375, 1010,
1
976, 748 cm21; H NMR ;CDCl3) d 0.98 ;t, Jˆ7.2 Hz,
3H), 1.10 ;d, Jˆ6.9 Hz, 3H), 2.30 ;dq, Jˆ18.0, 7.2 Hz,
1H), 2.47 ;dq, Jˆ18.0, 7.2 Hz, 1H), 2.74 ;dd, Jˆ6.9,
12.9 Hz, 1H), 3.00 ;ddq, Jˆ6.9, 6.9, 6.9 Hz, 1H), 3.09
;dd, Jˆ6.9, 12.9 Hz, 1H), 6.90 ;dt, Jˆ2.1, 7.2 Hz, 1H),
7.14 ;dd, Jˆ2.1, 7.2 Hz, 1H), 7.24 ;dt, Jˆ1.2, 7.2 Hz,
1H), 7.82 ;dd, Jˆ1.2, 7.2 Hz, 1H); 13C NMR ;CDCl3) d
7.52, 16.31, 35.29, 43.45, 45.52, 100.60, 128.17, 128.21,
130.80, 139.66, 142.38, 214.41. Found: C, 47.50;H,
4.89%. Calcd for C12H15IO: C, 47.70;H, 5.00%.
4.6. General procedure for the preparation of
manganese enolate
The reaction of benzaldehyde with manganese enolate,
derived from benzyl 2-iodopropanoate and activated
manganese, is representative. The suspension of activated
manganese ;1 mmol) in THF was added to a solution of
benzyl 2-iodopropanoate ;145 mg, 0.5 mmol) and benzalde-
hyde ;64 mg, 0.6 mmol) in THF ;10 mL) at 258C under
argon. The resulting mixture was stirred for 15 h at 258C.
The mixture was poured into sat. NH4Cl and extracted with
ethyl acetate ;20 mL£3). The combined organic layers were
dried over Na2SO4 and concentrated in vacuo. Puri®cation
by silica gel column chromatography afforded benzyl
3-hydroxy-2-methyl-3-phenylpropanoate ;10a) in 78%
yield.
4.4. Preparation of the suspension of activated
manganese
Magnesium turnings ;1.22 g, 50 mmol) were activated by
treatment with a solution of 1,2-dibromoethane ;0.94 g,
5 mmol) in THF ;10 mL) followed by washing with THF
;4 mL£3). Then, a pale yellow±green solution of Li2MnCl4
;15 mmol), derived from MnCl2 ;1.89 g, 15 mmol) and LiCl
;1.27 g, 30 mmol) in THF ;40 mL), was added to
magnesium turnings with vigorous stirring. The mixture
was stirred for 24 h at room temperature.13 The initial pale
yellow±green color turned dark. This resulting black
suspension of activated manganese in THF14 was stable
for at least one week at room temperature and was trans-
ferred in a reaction ¯ask with a syringe.
Spectroscopic data for benzyl 3-hydroxy-2-methyl-3-
phenylpropanoate ;10a),25 benzyl 3-hydroxy-2,4-dimethyl-
pentanoate ;10c),26 3-[hydroxy;phenyl)methyl]-terahydro-
furan-2-one ;20a),27 N,N-diethyl-3-hydroxy-2-methyl-3-
phenylpropanamide ;23a),28 and 4-hydroxy-3-methyl-4-
phenyl-2-butanone ;26)29,30 were identical with those
reported in literatures.
4.6.1. Benzyl 3-hydroxy-2-methylnonanoate /10b,
erythro/threoˆ52/48). IR ;neat) 3445, 2930, 2858, 1715,
4.5. General procedure for the preparation of allylic
manganese
1456, 1381, 1170, 1030, 737, 698 cm21
;
1H NMR
;CDCl3) d 0.88 ;t, Jˆ6.0 Hz, 3H), 1.16±1.53 ;m, 13H),
1.54±1.74 ;m, 1H), 2.53±2.64 ;m, 1H), 3.64±3.72 ;m,
0.48H), 3.86±3.94 ;m, 0.52H), 5.15 ;s, 2H), 7.30±7.42
;m, 5H); 13C NMR ;CDCl3) d 10.60, 14.01, 14.21, 22.54,
25.42, 25.87, 29.16, 31.71, 33.81, 34.68, 44.31, 45.26,
66.28, 66.35, 71.77, 73.37, 128.12, 128.15, 128.28,
128.31, 128.60, 135.78, 175.83, 175.98. HRMS Found:
m/z 260.1761. Calcd for C17H24O2: ;M2H2O), 260.1776.
The reaction of benzaldehyde ;2a) with allylmanganese
bromide, generated from allyl bromide and activated
manganese, is representative. The suspension of activated
manganese ;3.0 mmol) in THF was added to a solution of
allyl bromide ;121 mg, 1.0 mmol) and benzaldehyde
;212 mg, 2.0 mmol) in THF/hexane ;7/5 mL) at 2428C
with a syringe. The mixture was stirred at 2428C for 1 h.
The whole mixture was warmed up to room temperature
over a period of 1.5 h. The resulting mixture was poured
into sat. NH4Cl and extracted with ethyl acetate ;20 mL£3).
The combined organic layers were dried over Na2SO4 and
concentrated in vacuo. The crude product was puri®ed by
silica gel column chromatography ;hexane/ethyl acetateˆ3/
1) to provide 1-phenyl-3-buten-1-ol ;3a) in 82 % yield.
4.6.2. Benzyl 3-hydroxy-2,4-dimethyl-4-heptenoate /10d,
erythro/threoˆ41/59). IR ;neat) 3447, 2964, 2937, 1732,
1
1456, 1256, 1169, 1024 cm21; H NMR ;CDCl3) d 0.94
;t, Jˆ7.8 Hz, 1.77H), 0.96 ;t, Jˆ7.8 Hz, 1.23H), 1.05 ;d,
Jˆ7.2 Hz, 1.23H), 1.18 ;d, Jˆ7.2 Hz, 1.77H), 1.58 ;s,
1.77H), 1.59 ;s, 1.23H), 1.93±2.10 ;m, 2H), 2.11±2.50
;bs, 1H), 2.65±2.80 ;m, 1H), 4.11 ;d, Jˆ9.0 Hz, 0.41H),
4.27 ;d, Jˆ5.4 Hz, 0.59H), 5.11 ;s, 1.18H), 5.15
;d, Jˆ12.6 Hz, 0.41H), 5.18 ;d, Jˆ12.6 Hz, 0.41H),
Spectroscopic data for 1-phenyl-3-buten-1-ol ;3a),15
1-cyclohexyl-3-buten-1-ol ;3c),15 2-phenyl-4-penten-2-ol

H. Kakiya et al. / Tetrahedron 57 ,2001) 8807±8815
8813
5.39±5.50 ;m, 1H), 7.29±7.42 ;m, 5H); 13C NMR ;CDCl3)
d 10.56, 11.40, 12.28, 13.85, 13.93, 14.36, 20.73, 20.79,
40.10, 43.35, 66.30, 66.35, 79.90, 128.06, 128.12, 128.20,
128.23, 128.56, 129.04, 131.57, 133.26, 135.83, 135.88.
HRMS Found: m/z 244.1470. Calcd for C16H20O2:
;M2H2O), 244.1463.
6H), 3.00±3.80 ;bs, 1H), 5.15 ;s, 2H), 7.28±7.40 ;m, 5H);
13C NMR ;CDCl3) d 21.33, 25.12, 49.81, 66.58, 73.60,
128.01, 128.32, 128.60, 135.61, 178.27. HRMS Found:
m/z 236.1422. Calcd for C14H20O3: M, 236.1412.
4.6.9. 3-/1-Hydroxyheptyl)tetrahydrofuran-2-one /20b,
erythro/threoˆ60/40). IR ;neat) 3456, 2930, 2858, 1755,
1
1460, 1379, 1217, 1173, 1024 cm21; H NMR ;CDCl3) d
4.6.3. Benzyl 3-hydroxy-2,3-dimethylbutanoate /10e). IR
;neat) 3445, 2978, 1732, 1383, 1342, 1196, 1134, 784,
0.89 ;t, Jˆ6.9 Hz, 3H), 1.20±1.60 ;m, 10.6H), 1.95±2.12
;m, 0.4H), 2.13±2.26 ;m, 0.6H), 2.27±2.46 ;m, 1H), 2.52±
2.72 ;m, 1H), 3.00±3.60 ;bs, 0.4H), 3.71±3.82 ;m, 0.4H),
4.14±4.28 ;m, 1.6H), 4.34±4.45 ;m, 1H); 13C NMR ;CDCl3)
d 13.92, 21.61, 22.46, 24.91, 25.71, 28.99, 29.07, 31.64,
34.59, 34.82, 44.41, 45.40, 66.89, 67.12, 69.11, 71.71,
178.93, 179.71. HRMS Found: m/z 182.1311. Calcd for
C11H18O2: ;M2H2O), 182.1307.
698 cm21 1H NMR ;CDCl3) d 1.19 ;s, 3H), 1.23 ;d,
;
Jˆ7.2 Hz, 3H), 1.24 ;s, 3H), 2.55 ;q, Jˆ7.2 Hz, 1H),
2.62±3.04 ;bs, 1H), 5.16 ;s, 2H), 7.31±7.41 ;m, 5H); 13C
NMR ;CDCl3) d 12.56, 25.87, 28.74, 49.16, 66.37, 71.05,
128.22, 128.37, 128.62, 135.61, 176.29. Found: C, 69.97;H,
8.31%. Calcd for C13H18O3: C, 70.25;H, 8.16%.
4.6.4. Benzyl 2-/1-hydroxy-2-cyclohexen-1-yl)propano-
ate /10f, erythro/threoˆ55/45). IR ;neat) 3501, 2939,
4.6.10. 3-/1-Hydroxy-2-butenyl)tetrahydrofuran-2-one
/20c, erythro/threoˆ55/45). IR ;neat) 3450, 2918, 1760,
1
1728, 1456, 1337, 1161, 964, 739, 698 cm21; H NMR
1
1452, 1380, 1178, 1024, 970 cm21; H NMR ;CDCl3) d
;CDCl3) d 1.21 ;d, Jˆ7.2 Hz, 1.35H), 1.24 ;d, Jˆ7.5 Hz,
1.65H), 1.53±1.82 ;m, 4H), 1.84±2.12 ;m, 2H), 2.64 ;q,
Jˆ7.2 Hz, 0.45H), 2.68 ;q, Jˆ7.2 Hz, 0.55H), 2.90±3.40
;bs, 1H), 5.15 ;s, 1.1H), 5.17 ;s, 0.9H), 5.53 ;d,
Jˆ10.5 Hz, 0.45H), 5.78 ;d, Jˆ10.2 Hz, 0.55H), 5.82±
5.91 ;m, 1H), 7.28±7.40 ;m, 5H); 13C NMR ;CDCl3) d
12.12, 18.39, 18.64, 24.98, 31.70, 34.49, 48.32, 66.28,
66.42, 70.18, 70.31, 128.19, 128.28, 128.33, 128.57,
128.60, 129.00, 130.98, 131.03, 131.52, 135.65, 135.76,
175.84, 175.96. HRMS Found: m/z 242.1307. Calcd for
C16H20O3: ;M2H2O), 242.1315.
1.73 ;d, Jˆ6.6 Hz, 3H), 1.96±2.13 ;m, 0.45H), 2.16±2.41
;m, 2.10H), 2.64±2.81 ;m, 1H), 3.52±3.85 ;bs, 0.45H),
4.17±4.30 ;m, 1.45H), 4.33±4.43 ;m, 1H), 4.61 ;dd,
Jˆ6.6, 3.0 Hz, 0.55H), 5.44±5.57 ;m, 1H), 5.74±5.88 ;m,
1H); 13C NMR ;CDCl3) d 17.56, 17.65, 22.28, 25.49, 44.62,
45.36, 67.05, 67.28, 70.58, 73.19, 128.73, 129.69, 129.80,
130.22, 178.55, 178.13.
4.7. General procedure for the preparation of aryl
manganese
4.6.5. Benzyl 3-hydroxy-2,2-dimethyl-3-phenylpropano-
ate /17a). IR ;neat) 3497, 2978, 1720, 1470, 1454, 1250,
The reaction of iodobenzene with activated manganese is
representative. The suspension of manganese ;4.0 mmol) in
THF was added to a THF solution of iodobenzene ;408 mg,
2.0 mmol) at 08C. After stirring for 2 h at 08C, benzaldehyde
;106 mg, 1.0 mmol) was added and the whole mixture was
stirred for 20 h at 258C. The reaction was quenched with sat.
NH4Cl and extracted with ethyl acetate ;20 mL£3). Puri®-
cation by silica gel column chromatography afforded
diphenylmethanol ;28a) in 21% yield.
1
1130, 1049, 745, 704 cm21; H NMR ;CDCl3) d 1.13 ;s,
3H), 1.18 ;s, 3H), 2.64±3.36 ;bs, 1H), 4.93 ;s, 1H), 5.17 ;s,
2H), 7.24±7.40 ;m, 10H); 13C NMR ;CDCl3) d 18.98,
22.93, 47.77, 66.51, 78.60, 127.64, 127.72, 127.75,
127.90, 128.17, 128.55, 135.87, 139.90, 177.45.
4.6.6.
/17b). IR ;neat) 3420, 2970, 1715, 1456, 1387, 1261,
1138, 1028, 698 cm21 1H NMR ;CDCl3) d 0.79 ;d,
Benzyl
3-hydroxy-2,2,4-trimethylpentanoate
;
Spectroscopic data for ;4-¯uorophenyl)phenylmethanol
were identical with those reported in the literatures.31
Jˆ6.9 Hz, 3H), 0.94 ;d, Jˆ6.9 Hz, 3H), 1.21 ;s, 3H), 1.29
;s, 3H), 1.77±1.90 ;m, 1H), 2.66±2.99 ;bs, 1H), 3.42 ;d,
Jˆ3.9 Hz, 1H), 5.12 ;s, 2H); 13C NMR ;CDCl3) d 15.27,
21.64, 22.36, 23.49, 29.90, 46.05, 66.45, 81.46, 128.04,
128.24, 128.55, 135.60, 177.88. HRMS Found: m/z
250.1573. Calcd for C15H22O3: M, 250.1569.
4.7.1. Phenyl[2-/tri¯uoromethyl)phenyl]methanol. IR
;neat) 3344, 3066, 3034, 1609, 1585, 1454, 1313, 1161,
1
1124, 1038, 1020, 768, 737, 700 cm21; H NMR ;CDCl3)
d 2.31 ;s, 1H), 6.32 ;s, 1H), 7.24±7.44 ;m, 6H), 7.55 ;dd,
Jˆ7.2, 7.2 Hz, 1H), 7.64±7.70 ;m, 2H); 13C NMR ;CDCl3)
d 70.83, 124.47 ;q, Jˆ273 Hz), 125.60 ;q, Jˆ5.7 Hz),
126.51, 127.63, 127.72 ;q, Jˆ29.9 Hz), 127.82, 128.46,
129.59, 132.40, 142.44, 142.83. Found: C, 66.71;H,
4.41%. Calcd for C14H11F3O: C, 66.67;H, 4.40%.
4.6.7. Benzyl 3-hydroxy-2,2,4-trimethyl-4-heptenoate
/17c). IR ;neat) 3483, 2966, 1720, 1458, 1254, 1132,
1
698 cm21; H NMR ;CDCl3) d 0.95 ;t, Jˆ7.5 Hz, 3H),
1.17 ;s, 3H), 1.23 ;s, 3H), 1.55 ;s, 3H), 1.93±2.10 ;m,
2H), 2.96 ;bs, 1H), 4.10 ;s, 1H), 5.12 ;d, Jˆ12.3 Hz, 1H),
5.16 ;d, Jˆ12.3 Hz, 1H), 5.36 ;t, Jˆ6.9 Hz, 1H), 7.31±7.39
;m, 5H); 13C NMR ;CDCl3) d 12.76, 13.79, 20.83, 20.89,
23.82, 46.65, 66.48, 82.60, 127.95, 128.20, 128.56, 131.86,
133.18, 135.78, 177.69. HRMS Found: m/z 258.1631. Calcd
for C17H22O3: ;M2H2O), 258.1620.
4.7.2. 1-[2-/Tri¯uoromethyl)phenyl]-1-heptanol. IR
;neat) 3363, 2928, 2860, 1609, 1585, 1456, 1313, 1163,
1
1122, 1059, 1036, 768 cm21; H NMR ;CDCl3) d 0.88 ;t,
Jˆ6.6 Hz, 3H), 1.01±1.40 ;m, 7H), 1.45±1.60 ;m, 1H),
1.62±1.80 ;m, 2H), 1.94 ;bs, 1H), 5.11 ;t, Jˆ6.6 Hz, 1H),
7.36 ;t, Jˆ7.2 Hz, 1H), 7.54±7.64 ;m, 2H), 7.77 ;d,
Jˆ7.8 Hz, 1H); 13C NMR ;CDCl3) d 13.89, 22.44, 25.98,
28.92, 31.60, 39.13, 69.51, 124.52 ;q, Jˆ273 Hz), 125.47
;q, Jˆ6.1 Hz), 126.92 ;q, Jˆ30 Hz), 127.42, 127.62,
4.6.8. Benzyl 3-hydroxy-2,2,3-trimethylbutanoate /17d).
IR ;neat) 3493, 2980, 1713, 1468, 1377, 1269, 1117, 955,
1
737, 698 cm21; H NMR ;CDCl3) d 1.17 ;s, 6H), 1.26 ;s,

8814
H. Kakiya et al. / Tetrahedron 57 ,2001) 8807±8815
Commun. 1998, 28, 1065±1072. ;d) Kim, S.-H.;Rieke, R. D.
J. Org. Chem. 2000, 65, 2322±2330. ;e) Hojo, M.;Yoshizawa,
J.;Funahashi, Y.;Okada, R.;Nakamura, S.;Tateiwa, J.;
Hosomi, A. Heterocycles 1998, 49, 85±88. ;f) Cahiez, G.;
Martin, A.;Delacroix, T. Tetrahedron Lett. 1999, 40, 6407±
6410.
132.36, 144.42. Found: C, 64.76;H, 7.46%. Calcd for
C14H19F3O: C, 64.60;H, 7.36%.
4.8. General procedure for the manganese-mediated
cyclization reaction
4. Activation of manganese metal with additives. See:
;a) Cahiez, G.;Chavant, P.-Y. Tetrahedron Lett. 1989, 30,
7373±7376. ;b) Takai, K.;Ueda, T.;Hayashi, T.;Moriwake,
T. Tetrahedron Lett. 1996, 37, 7049±7052. ;c) Hiyama, T.;
Sawahata, M.;Obayashi, M. Chem. Lett. 1983, 1237±1238.
5. We cannot exclude the possibility that the remaining ®ne
particle of magnesium might play a critical role for the forma-
tion of organometallic reagent. In the paper that we reported
previously, however, the blank test without manganese
species was performed. Treatment of 2-iodoethanal butyl
1-vinylhexyl acetal with the supernatant of fully activated
magnesium in THF provided no expected cyclization product
and the starting material was recovered. See: Tang, J.;
Shinokubo, H.;Oshima, K. Tetrahedron 1999, 55, 1893±
1904.
The reaction of 1-;2-iodophenyl)-2,2,4-trimethyl-3-penta-
none ;29a) with activated manganese is representative.
The suspension of manganese ;1.5 mmol) in THF was
added to a solution of 1-;2-iodophenyl)-2,2,4-trimethyl-3-
pentanone ;165 mg, 0.5 mmol) in THF ;15 mL) at 2428C
under argon atmosphere. The mixture was stirred for 1.5 h at
2428C and at 08C for additional 1.5 h. The whole mixture
was warmed up to room temperature over 30 min and stirred
for another 17 h. Extractive workup ;ethyl acetate/sat.
NH4Cl) followed by silica gel column puri®cation provided
1-isopropyl-2,2-dimethyl-2,3-dihydroinden-1-ol ;32a) in
65% yield.
Spectroscopic data for 1-isopropyl-2,2-dimethyl-2,3-
dihydroinden-1-ol ;32a)11b and 2,2-dimethyl-1-phenyl-2,3-
dihydroinden-1-ol ;32b)11b were identical with those
reported in literatures.
6. Tang, J.;Shinokubo, H.;Oshima, K. Synlett 1998, 1075±
1076.
7. The order of the addition of reagents is crucial. After a mixture
of allyl bromide and activated manganese had been stirred at
2428C for 1 h, an addition of benzaldehyde to the mixture
afforded none of the desired homoallyl alcohol, 1-phenyl-3-
buten-1-ol.
4.8.1. 1-Ethyl-2-methyl-2,3-dihydroinden-1-ol /32c, 81/
1
19). IR ;neat) 3416, 2966, 2930, 1460, 756, 731 cm21; H
NMR ;CDCl3) d 0.89 ;t, Jˆ7.5 Hz, 2.43H), 0.91 ;t,
Jˆ7.2 Hz, 0.57H), 1.09 ;d, Jˆ6.9 Hz, 2.43H), 1.15 ;d,
Jˆ6.6 Hz, 0.57H), 1.44±1.64 ;m, 1.19H), 1.66±1.79 ;m,
0.19H), 1.81±2.00 ;m, 1.62H), 2.30±2.51 ;m, 1.19H),
2.62 ;dd, Jˆ15.6, 6.9 Hz, 0.81H), 3.00 ;dd, Jˆ15.6,
7.5 Hz, 1H); 13C NMR ;CDCl3) d 7.58, 9.03, 13.18,
13.77, 21.20, 30.79, 37.64, 37.99, 40.82, 48.61, 84.04,
84.29, 123.37, 123.93, 124.75, 125.08, 126.19, 126.61,
127.72, 128.23, 141.68, 142.80, 146.61, 147.83. HRMS
Found: m/z 176.1198. Calcd for C12H16O: M, 176.1201.
8. For reviews of the Reformatsky reaction, see: ;a) Rathke,
M. W.;Weipert, P. In Comprehensive Organic Synthesis;
Trost, B. M., Fleming, I., Eds.;Pergamon Press: Oxford,
1991;Vol. 2, pp. 277±299. ;b) FuÈrstner, A. Synthesis 1989,
571±590.
9. We have reported that the reaction of a,a-dibromo esters or
a,a-dibromo amides with trialkylmanganates provided alkyl-
ated manganese enolates Inoue, R.;Shinokubo, H.;Oshima,
K. J. Org. Chem. 1998, 63, 910±911.
10. Formation and reaction of manganese enolates. Deprotona-
Á Â
tion: ;a) Cahiez, G.;Figade re, B.;Cle ry, P. Tetrahedron
Lett. 1994, 35, 3065±3068. Transmetalation: ;b) Cahiez, G.;
Acknowledgements
Â
Chau, K.;Cle ry, P. Tetrahedron Lett. 1994, 35, 3069±3072.
Financial support by Grant-in-Aids for Scienti®c Research
on ;Nos. 10208208 and 09450341) from the Ministry of
Education, Culture, Sports, Science, and Technology,
Japan, is acknowledged. H. K. thanks the JSPS Research
Fellowship for Young Scientists.
1,4-Addition: ;c) Cahiez, G.;Alami, M. Tetrahedron Lett.
1989, 30, 3541±3544. ;d) Takai, K.;Ueda, T.;Kaihara, H.;
Sunami, Y.;Moriwake, T. J. Org. Chem. 1996, 61, 8728±
8729. Halogen±metal exchange: ;e) Hojo, M.;Harada, H.;
Ito, H.;Hosomi, A. J. Am. Chem. Soc. 1997, 119, 5459±5460.
11. Several examples for cyclization of tethered haloaryl ketones
by other metal were reported ;a) Halterman, R. L.;Zhu, C.
Tetrahedron Lett. 1999, 40, 7445±7448. ;b) Quan, L. G.;
Lamrani, M.;Yamamoto, Y. J. Am. Chem. Soc. 2000, 122,
4827±4828.
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;2 mL) at 08C under argon. The excess hydrochloric acid

H. Kakiya et al. / Tetrahedron 57 ,2001) 8807±8815
8815
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