Efficient and widely applicable oxidation method of tribromomethyl carbinols with PCC

Article abstract of DOI:10.1080/00397911.2017.1415358

An efficient and widely applicable oxidation method of tribromomethyl carbinols in the presence of pyridinium chlorochromate has been developed with excellent yields up to 96%. This method was well applied for the oxidation of a variety of aromatic, aliph

Full text of DOI:10.1080/00397911.2017.1415358

Synthetic Communications
An International Journal for Rapid Communication of Synthetic Organic
Chemistry
ISSN: 0039-7911 (Print) 1532-2432 (Online) Journal homepage: http://www.tandfonline.com/loi/lsyc20
Efficient and widely applicable oxidation method
of tribromomethyl carbinols with PCC
Balati Hasimujiang, Jing Zeng, Zhang Yanhui & Abulikemu Abudu Rexit
To cite this article: Balati Hasimujiang, Jing Zeng, Zhang Yanhui & Abulikemu Abudu Rexit (2018):
Efficient and widely applicable oxidation method of tribromomethyl carbinols with PCC, Synthetic
Communications, DOI: 10.1080/00397911.2017.1415358
To link to this article: https://doi.org/10.1080/00397911.2017.1415358
View supplementary material
Published online: 09 Mar 2018.
Submit your article to this journal
Article views: 5
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at
http://www.tandfonline.com/action/journalInformation?journalCode=lsyc20

SYNTHETIC COMMUNICATIONS®
https://doi.org/10.1080/00397911.2017.1415358
Efficient and widely applicable oxidation method of
tribromomethyl carbinols with PCC
Balati Hasimujiang, Jing Zeng, Zhang Yanhui, and Abulikemu Abudu Rexit
Department of Chemistry, Xinjiang Normal University, Urumqi, China
ABSTRACT
ARTICLE HISTORY
Received 17 September 2017
An efficient and widely applicable oxidation method of tribromo-
methyl carbinols in the presence of pyridinium chlorochromate has
been developed with excellent yields up to 96%. This method was
well applied for the oxidation of a variety of aromatic, aliphatic, and
heterocyclic tribromomethyl carbinols.
KEYWORDS
Oxidation; PCC;
tribromomethyl carbinols;
tribromomethyl ketones
GRAPHICAL ABSTRACT
Introduction
As highly versatile starting materials and intermediates in organic and organometallic
chemistry, multihalogenated compounds have received consistent attention.[1–9] Among
them, polyhalomethyl ketones and especially polybromomethyl ketones are useful
[
10–12]
building blocks in the preparation of multifunctional compounds
and important
[
13,14]
intermediates in a lot of organic transformations like cyclopropanation reactions.
Fundamental approaches for the synthesis of tribromomethyl ketones are mainly based
on oxy-halogenation of alkynes.[15–16] Meanwhile, recent approaches involved the use of
[
17]
[18]
various bromination reagents, such as CBr COCl,
hexabromo cyclopentadien,
3
molecular bromine,[19] H O –HBr,
[20–21]
hexabromo cyclopentadiene,
[22]
to obtain
2
2
tribromomethyl ketones (Scheme 1). An alternative strategy involved the use of Na Cr O
2 7
2
as oxidation to convert tribromomethyl carbinols into corresponding ketones.[23]
Comparing to the preparations of trichloromethyl ketones which are mostly studied,
strategies to facilitate access to tribromomethyl ketones are greatly demanded owing to
the high reactivity of brominated organic compounds.[24] However, present synthetic
limitations in the synthesis of tribromomethyl ketones are in evidence, hash conditions
or moisture sensitive reagents are usually involved and it is still of challenge to obtain
high yields during the oxidation process. Herein, we will report an efficient and widely
applicable oxidation method for the preparation of tribromomethyl ketone compounds.
CONTACT Abulikemu Abudu Rexit
Urumqi 830054, China.
aarexit@mail.ustc.edu.cn
Department of Chemistry, Xinjiang Normal University,
Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/lsyc.
Supplemental data for this article can be accessed on the publisher’s website.
©
2018 Taylor & Francis

2
B. HASIMUJIANG ET AL.
Scheme 1. Strategies for preparation of tribromomethyl ketones.
Results and discussion
Oxidative reactions of 2,2,2-tribromo-1-phenylethanol 1a with different oxidants were
performed as illustrated in Table 1. Various representative oxidants (Na Cr O ,
2
2 7
K Cr O , tert-butyl hydroperoxide (TBHP), dimethyl phthalate (DMP), pyridinium
2
2 7
chlorochromate (PCC)) were examined (Table 1, entries 1–5) and PCC was proved to
be the best option. And further exploration on oxidative protocol demonstrated that 2
equiv. of PCC could also promote the reaction equally well at room temperature, yet with
a prolonged reaction time to 52 h (Table 1, entry 5). As contrast, when the reaction was
performed at refluxing temperature in dichloromethane for 4 h (Table 1, entry 6), the
product yield could be 90%. While, when PCC decreased to 1.5 equivalents, the yield of
product 2a increased to 96% (Table 1, entry 7) as the optimized condition. When PCC
further decreased to 1.2 equiv., the yield significantly dropped to 65% (Table 1, entry 8).
Under the optimal condition (Table 1, entries 7 and 9), reaction solvents were
examined and dichloromethane was proved to be the optimal solvent compared to 1,
2
-dichloroethane.
Table 1. Optimization of the reaction conditions.
a
b
Entry
Oxidant
Na Cr
Cr
TBHP
DMP
PCC
PCC
PCC
PCC
PCC
Oxidant (equiv.)
Solvent
Temp. (°C)
Time (h)
Yield (%)
1
2
3
4
5
6
7
8
9
2
2
O
7
7
0.6
0.6
6
AcOH
AcOH
MeOH
rt
rt
5
5
5
5
52
4
4
24
4
65
45
K
2
2
O
rt
No reaction
2
CH
CH
CH
CH
CH
2
2
2
2
2
Cl
Cl
Cl
Cl
Cl
2
2
2
2
2
rt
78
94
90
96
65
91
2
rt
2
reflux
reflux
reflux
reflux
1.5
1.2
1.5
DCE
PCC, pyridinium chlorochromate.
a
Oxidant added to a stirred solution of 1a (0.5 mmol) in solvent (10 ml) at reflux.
Isolated yield.
b

SYNTHETIC COMMUNICATIONS®
3
a
Table 2. Evaluation of tribromomethyl carbinol substrates.
b
Entry
1
Substrate
Product
Time (h)
4
Yield (%)
96
85
94
80
85
86
81
2
3
4
5
6
7
9
10
7
16
8
11
8
9
8
80
11
12
88
81
10
(Continued)

4
B. HASIMUJIANG ET AL.
Table 2. Continued.
b
Entry
Substrate
Product
Time (h)
12
Yield (%)
67
1
1
12
11
95
PCC, pyridinium chlorochromate.
a
The reactions of PCC (1.5 mmol) was added to a stirred solution of 1a (1 mmol) in CH
Cl
2 2
(10 ml) at reflux.
b
Isolated yield.
The various substrates of tribromomethyl carbinols were screened out under optimized
reaction conditions. The results showed that the established oxidation methodology
could be used for such a variety of tribromomethyl carbinols as aromatic, aliphatic, and
heterocyclic (Table 2). Meanwhile, substituent on ortho-position showed negative effect
in this process with a lower yield obtained. As shown in entries 2 and 3 of Table 2,
2
,2,2-tribromo-1-(o-tolyl)ethanol 1b and 2,2,2-tribromo-1-(p-tolyl)ethanol 1c were
oxidized in the presence of PCC, affording corresponding ketones 2b and 2c in 85 and
4% yield, respectively. When a halogen atom as the electron-donating group was
9
introduced to the benzene ring in 1d–g and 1i, moderate yield between 80 and 94% was
obtained (Table 2, entries 3–7 and 9). Aliphatic tribromomethyl carbionls were also well
tolerated under this condition, affording the product with considerable yields. And for
heterocyclic tribromomethyl carbinol 2l, the yield could reach up to 95% (entry 12,
Table 2).
Experimental
General procedure for the oxidative reaction
Pyridinium chlorochromate (1.5 mmol, 1.5 equiv.) was added to a stirred CH Cl (10 ml)
2
2
solution of 2,2,2-tribromo-1-phenylethanol 1a (1 mmol, 1 equiv.), and the mixture was
heated to reflux. The reaction progress was monitored by TLC. After the completion of
reaction, the temperature was cooled to room temperature, then filtered through a Celite
pad, and the filtrate was evaporated under reduced pressure to give the crude product
which was further purified by flash column chromatography using ethyl acetate and
petroleum ether (1:9) as an eluant, pure 2,2,2-tribromo-1-phenylethanone 2a (0.346 g,
9
6%) as a white solid was obtained.
Conclusion
In conclusion, an efficient and widely applicable synthetic method of tribromomethyl
ketones from tribromomethyl carbinols in the presence of PCC has been successfully
developed. The corresponding tribromomethyl ketone compounds could be obtained in
good to excellent yields. This protocol oxidation method may also be applied to a variety
of different tribromomethyl carbinols, such as aromatic, aliphatic, and heterocyclic.

SYNTHETIC COMMUNICATIONS®
5
Funding
We are grateful for financial support from Funded by Scientific Research Program of the Higher
Education Institution of Xinjiang, China (XJEDU2014I026).
References
[
[
[
[
[
[
[
[
[
1] French, A. N.; Bissmire, D.; Wirth, T. Chem. Soc. Rev. 2004, 33, 354–362.
2] Stavber, S.; Jereb, M.; Zupan, M. Synthesis 2008, 2008, 1487–1513.
3] Podgorsek, A.; Zupan, M.; Iskra, J. Angew. Chem. Int. Ed. 2009, 48, 8424–8450.
4] Zhdankin, V. V.; Stang, P. J. Chem. Rev. 2008, 108, 5299–5358.
5] Rexit, A. A.; Hu, X. Tetrahedron 2015, 71, 2313–2316.
6] Kenneth, T.; Ravindra, N. B.; Neal, D. M. J. Heterocyclic Chem. 2000, 37, 383–388.
7] Yasuji, I.; Katsuhiro, I.; Hideo, T. Bull. Chem. Soc. Jpn. 1983, 56, 1490–1496.
8] Chiappe, C.; Leandri, E.; Tebano, M. Green Chem. 2006, 8, 742–745.
9] Kimpe, N.; Verhe, R. In The Chemistry of α-Haloketones, α-Haloaldehydes and α-Haloimines;
Patai, S., Rappoport, Z., Eds.; John Wiley and Sons: Chichester, UK, 1988.
[
10] Olah, G. A.; Laali, K. K.; Wang, Q.; Prakash, G. K. S. Onium Ions; JohnWiley and Sons:
New York, 1998.
[
[
[
[
[
[
[
[
[
[
11] Kim, K.; Cho, J.; Yoon, S. C. J. Chem. Soc., Perkin Trans. 1995, 1, 253–259.
12] Zhdankin, V. V.; Stang, P. J. Tetrahedron Lett. 1993, 34, 1461–1462.
13] Fujiwara, J.; Matsumura, A.; Matsuoka, Y.; Kiji, J. Bull. Chem. Soc. Jpn. 1976, 49, 829–831.
14] Kawabata, N.; Fuji, T.; Naka, M.; Yamashita, S. Bull. Chem. Soc. Jpn. 1977, 50, 1005–1015.
15] Li, J.; Li, W.; Li, Y.; Li, Z. Tetrahedron Lett. 2011, 52, 4320–4323.
16] Nobuta, T.; Hirashima, S.; Tada, N.; Miura, T.; Itoh, A. Tetrahedron Lett. 2010, 51, 4576–4578.
17] Hitomi, S.; Mitsuyuki, K.; Tadashi, M. Bull. Chem. Soc. Jpn. 1981, 54, 1186–1190.
18] Shulamit, M.; Jakob, O.; Benzion, F. Tetrahedron Lett. 1984, 25, 3369–3372.
19] John, J. Parlow. Tetrahedron 1994, 50, 3297–3314.
20] Alexander, O. T.; Sergey, V. K.; Igor, B. K.; Yuri, N. O.; Gennady I. N. Synthesis 2006, 7,
1
087–1092.
[
21] Alexander, O. T.; Igor, B. K.; Vera, A. V.; Zhanna, Y. P.; Sergey, A. F.; Gennady, I. N. Eur. J.
Chem. 2012, 10, 360–367.
[22] Kotek, V.; Polak, P.; Dvorakova, H.; Tobrman, T. Eur. J. Org. Chem. 2016, 29, 5037–5044.
[23] Ping, W.; Senhan, X.; Hao, X.; Haiyan, H.; Wei, Z. Tetrahedron Lett. 2017, 58, 618–621.
[24] Yang, W.; Hu, W.; Dong, X.; Li, X.; Sun, J. Angew. Chem. Int. Ed. 2016, 55, 15783–15786.