G Model
CCLET-2847; No. of Pages 3
Chinese Chemical Letters
Original article
Triphenylphosphine-m-sulfonate/carbon tetrabromide as an easily
recoverable catalyst system for the efficient synthesis of xanthene and
xanthenone derivatives under solvent-free conditions
*
Cong-De Huo , Xia-Zhen Bao, Dong-Cheng Hu, Xiao-Dong Jia, Chou-Gu Sun, Cheng Wang
Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal
University, Lanzhou 730070, China
A R T I C L E I N F O
A B S T R A C T
Article history:
A solid complex, readily prepared from commercially available sodium triphenylphosphine-m-sulfonate
(TPPMS) and carbon tetrabromide, can be used as an easily recoverable and reusable catalyst system for
one-pot condensation of 2-naphthol with aldehydes to construct 14-aryl(alkyl)-14H-dibenzo[a,j]-
xanthene derivatives and one-pot condensation of 2-naphthol with aldehydes and cyclic 1,3-dicarbonyl
compounds to construct 12-aryl(alkyl)-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one derivatives.
ß 2014 Cong-De Huo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights
reserved.
Received 11 November 2013
Received in revised form 17 December 2013
Accepted 2 January 2014
Available online xxx
Keywords:
Xanthene
Xanthenone
Naphthol
Aldehyde
1. Introduction
but can be easily recovered from the reaction mixture by adding
a non-polar solvent such as ether. Furthermore, the recovered
Xanthenes exhibit a range of important biological activities
such as anti-inflammatory, anti-viral, and anti-bacterial properties
[1]. Moreover, due to their spectroscopic properties, xanthenes are
used as dyes and fluorescent materials for the visualization of
biomolecules [2]. Xanthenones, especially tetrahydroxanthenones,
are also an important class of compounds for their distinct
structural features and great potential for further transformations
[3]. Therefore, the synthesis of xanthene and xanthenone
derivatives is of great importance [4]. The development of green
and practical methods to construct these skeletons is still highly
desired.
Recently, commercially available sodium triphenylphosphine-
m-sulfonate (TPPMS) was developed as an ion-tagged reagent to
mediate a facile Wittig reaction [5]. Afterwards, we demonstrated
the use of the TPPMS/CBr4 complex as a highly efficient catalyst
system for the preparation of acetals from aldehydes, the
tetrahydropyranylation of alcohols, and Friedel–Crafts alkylation
of indoles with carbonyl compounds to produce bis(indolyl)alkane
products (BIAs) (Scheme 1) [6]. These reactions utilize the TPPMS/
CBr4 system as a solid complex, which is stable and can be stored
easily. The catalyst is soluble in relatively polar organic solvents
catalyst can be reused. Multicomponent condensation reaction is
a powerful tool for the construction of molecular complexity and
structural diversity. Due to their use of one-pot and inherently
simple experimental procedure, the development of more
sustainable and greener multicomponent reactions is highly
desired. As a part of our ongoing program to explore new catalytic
activities for this solubility controllable TPPMS/CBr4 complex, an
efficient one-pot condensation of 2-naphthol with aldehydes to
construct 14-aryl(alkyl)-14H-dibenzo[a,j]xanthenes derivatives
and one-pot condensation of 2-naphthol with aldehydes and
cyclic 1,3-dicarbonyl compounds to construct 12-aryl(alkyl)-
8,9,10,12-tetrahydrobenzo[a]xanthen-11-one derivatives is intro-
duced in this paper (Scheme 1).
2. Experimental
2.1. Typical procedure for the synthesis of 12-aryl(alkyl)-8,9,10,12-
tetrahydrobenzo[a]xanthen-11-ones
A mixture of 1,3-dicarbonyl compounds (3, 1.2 mmol) and
TPPMS/CBr4 complex (0.05 mmol) was heated to 100 8C; 2-
naphthol (1, 1 mmol) and the appropriate aldehyde (2, 1 mmol)
were then added under stirring. After the reaction was completed
(as indicated by TLC), DCM (2 mL) and ether (2 mL) were added
successively, and the solid TPPMS/CBr4 complex was recovered by
*
Corresponding author.
1001-8417/$ – see front matter ß 2014 Cong-De Huo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Please cite this article in press as: C.-D. Huo, et al., Triphenylphosphine-m-sulfonate/carbon tetrabromide as an easily recoverable
catalyst system for the efficient synthesis of xanthene and xanthenone derivatives under solvent-free conditions, Chin. Chem. Lett.