tóm tắt luận án cu based organic frameworks as catalysts for c c and c n coupling reactions (tiếng anh)

Three Cu-MOFs including Cu3BTC2, Cu2BDC2DABCO, Cu2BPDC2BPY were used as heterogeneous catalysts for direct CC coupling reactions to synthesize propargylamines.. Especially, the Cu-MOFs

VIETNAM NATIONAL UNIVERSITY – HO CHI MINH CITY

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY

DANG HUYNH GIAO

Cu-BASED ORGANIC FRAMEWORKS AS CATALYSTS

FOR C–C AND C–N COUPLING REACTIONS

Major: Organic Chemical Technology

Major code: 62527505

PhD THESIS SUMMARY

HO CHI MINH CITY 2015

The thesis was completed in University of Technology –VNU-HCM

Advisor 1: Prof Dr Phan Thanh Son Nam

Advisor 2: Dr Le Thanh Dung

Independent examiner 1: Prof Dr Dinh Thi Ngo

Independent examiner 2: Assoc Prof Dr Nguyen Thi Phuong Phong

Examiner 1: Assoc Prof Dr Nguyen Cuu Khoa

Examiner 2: Assoc Prof Dr Nguyen Thai Hoang

Examiner 3: Assoc Prof Dr Le Thi Hong Nhan

The thesis will be defended before thesis committee at

On………

The thesis information can be looked at following libraries:

- General Science Library Tp HCM

- Library of University of Technology – VNU-HCM

Abstract

Four highly porous Copper-based organic frameworks (Cu-MOFs) such

as Cu3(BTC)2, Cu2(BDC)2(DABCO), Cu2(BPDC)2(BPY) and Cu(BDC) were synthesized and characterized by X-ray powder diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma mass spectrometry (ICP-MS), hydrogen temperature-programmed reduction (H2-TPR) and nitrogen physisorption measurements Three Cu-MOFs including Cu3(BTC)2, Cu2(BDC)2(DABCO),

Cu2(BPDC)2(BPY) were used as heterogeneous catalysts for direct CC coupling reactions to synthesize propargylamines Cu(BDC) was employed as heterogeneous catalyst for CN coupling reaction to synthesize quinoxalines These catalytic systems offered practical approaches with high yields and selectivity Additionally, broad functionality was shown to be compatible The Cu-MOFs catalysts could be recovered and reused several times without significant degradation in catalytic activity To the best of our knowledge, these transformations using Cu-MOFs catalysts were not previously mentioned in the literature

INTRODUCTION

Homogeneous transition metals are often employed as catalysts to promote the transformation of an organic compound in the liquid phase However, difficulties in removing catalyst impurities in the final products narrow the application of homogeneous catalytic systems, especially in pharmaceutical industry Metal-organic frameworks (MOFs) have recently attracted significant attention with advantages in replacing homogeneous catalysts in chemical process

Propargylamines and quinoxalines have emerged as important intermediates in the synthesis of numerous nitrogen-containing biologically active compounds as well as a variety of functional organic materials Many transition-metal catalytic systems, both in homogeneous and heterogeneous catalysis, were applied for the preparation of propargylmines and quinoxalines via the C−C and C−N coupling reations However, many of those processes suffered from one or more limitations such as harsh reaction conditions, low product yields, tedious work-up procedures, and the use of toxic metal salts as catalysts Consequently, study for the high-effective, sustainable synthetic routes of proparylamines and quinoxalines is an unquestionable trend in near future

Among several popular MOFs, copper-based organic frameworks MOFs) previously exhibited high activity in various organic reactions due to their unsaturated open copper metal sites Especially, the Cu-MOFs including

(Cu-Cu3(BTC)2, Cu(BDC), Cu2(BDC)2(DABCO) and Cu2(BPDC)2(BPY), which are constructed from copper salts and 1,4-benzenedicarboxylic acid (BDC), 1,3,5-benzenetricarboxylic acid (BTC) and 4,4’-biphenyldicarboxylic acid (BPDC), exhibit many advantages for catalytic application Those organic linkers are commercial and relatively cheap These Cu-MOFs have surface areas higher than 1000 m2/g (except for Cu(BDC)) and thermal stability of up to 300 °C or

higher Moreover, the largest pore apertures of Cu2(BDC)2(DABCO),

Cu3(BTC)2 and Cu2(BPDC)2(BPY) are in the range of 7.5 – 9.0 Å which can allow average size substrates to enter the pores and reach catalytic sites However, to the best of our knowledge, the direct C–C and C–N coupling reactions for the synthesis of proparylamines and quinoxalines using these Cu-MOFs were not previously mentioned in the literature

The first purpose of this thesis is to synthesize Cu-MOFs including

Cu3(BTC)2, Cu(BDC), Cu2(BDC)2(DABCO) and Cu2(BPDC)2(BPY) The second objective is to study their use as heterogeneous catalysts for the direct C–C and C–N coupling reactions to form proparylamines and quinoxalines

CHAPTER 1 LITERATURE REVIEW: Cu 3 (BTC) 2 ,

Cu 2 (BDC) 2 (DABCO), Cu 2 (BPDC) 2 (BPY), Cu(BDC) AND C–C, C–N COUPLING REACTIONS

1.1 Introduction to metal-organic frameworks

 In comparison with other porous materials, MOFs possess unique structures, in which the metal ions combine with organic linkers

to form secondary building units (SBUs), which dictate the final topology of a whole framework The combination of numerous kinds of linkers and metal ions can lead to considerable diversity of this material

 Many studies reported MOFs containing copper active sites as efficient heterogeneous catalysts

 Among organic linkers that are often used for Cu-MOFs synthesis, benzenedicarboxylic acid (BDC), 1,3,5-benzenetricarboxylic acid (BTC) and 4,4’-biphenyldicarboxylic acid (BPDC) have advantages that they are commercial and relatively cheap In another approach, MOFs can be constructed from mixed linkers to provide greater flexibility in terms of surface area, modifiable pore size and chemical environment Linkers BDC and BPDC could be easily combined with pillar linkers such as 1,4-diazabicyclo [2.2.2]octane (DABCO) or 4,4’-bipyridine (BPY) to form rigid Cu-MOFs Therefore, Cu-MOFs constructed from BDC, BTC or BPDC recently attracted great attention

1,4-1.1 1.2 Cu 3 (BTC) 2 , Cu(BDC), Cu 2 (BDC) 2 (DABCO) and

Cu 2 (BPDC) 2 (BPY)

 Cu3(BTC)2, Cu(BDC), Cu2(BDC)2(DABCO) and Cu2(BPDC)2(BPY) constitute Cu-MOFs that contain common SBUs of two 5-coordinate copper cations bridged in a paddle wheel-type configuration (Fig 1.4)

Fig 1.4 Common coordination geometry of paddle wheel building units of

Cu3(BTC)2, Cu2(BDC)2(DABCO), Cu2(BPDC)2(BPY), Cu(BDC) and their framework structures (L = Carboxylate linker, P = N-containing bidentate pillar

linker and G = Guest molecule)

 Cu3(BTC)2, Cu(BDC), Cu2(BDC)2(DABCO) and Cu2(BPDC)2(BPY) are synthesized by solvothermal methods Their physicochemical properties are presented in Table 1.2:

Table 1.2: Physicochemical properties of Cu3(BTC)2, Cu(BDC),

Cu2(BDC)2(DABCO) and Cu2(BPDC)2(BPY)

temperature (°C)

BET surface area (m2/g)

Pore aperture (Å2)

 Cu3(BTC)2, Cu(BDC), Cu2(BDC)2(DABCO) and Cu2(BPDC)2(BPY) can be characterized by various techniques, such as single crystal X-ray diffraction (SC-XRD), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), inductively coupled plasma mass spectrometry (ICP-MS), and gas physisorption measurement, etc

1.3 C–C coupling reactions

 Traditional routes to access propargylamines often suffer from disadvantages such as hard conditions, low yields, and limited reaction scopes

 Difficults in removing catalysts contaminated in final products narrow the application of homogeneous catalytic systems, especially in pharmaceutical industry

 Recently, the most attractive synthetic route is the use of Manich-type reaction, a three component procedure of terminal alkynes, formaldehyde, and secondary amines However, the aldehyde-free, oxidative Manich reactions have not been previously reported under any catalysis

1.4 C–N coupling reactions

 Traditionally, quinoxalines have been prepared by the acid-catalyzed condensation of 1,2-aryldiamines with 1,2-diketone or 1,2-diketone alternatives, such as epoxides, α-bromoketones, and α-hydroxyketones

 Although the contamination of the desired products with transition metals or other solids would be minimized under heterogeneous catalysts conditions, developing an efficient heterogeneous catalyst system for the quinoxaline synthesis still remains to be explored

1.2 1.5 Aim and objectives

 Propargylamines and quinoxalines are frequently found as the versatile intermediates for the synthesis of many nitrogen-containing biologically active compounds

 Cu3(BTC)2, Cu2(BDC)2(DABCO), Cu2(BPDC)2(BPY) and Cu(BDC) have many advantages for suitable catalytic applications

 To the best of our knowledge, the direct C–C and C–N coupling reactions for synthesizing proparylamines and quinoxalines using these Cu-MOFs were not previously mentioned in the literature

 The main aim of this dissertation is using Cu3(BTC)2,

Cu2(BDC)2(DABCO), Cu2(BPDC)2(BPY) and Cu(BDC) as catalysts for the synthesis of proparylamines and quinoxalines:

i) Synthesis and characterization of the Cu-MOFs including

Cu3(BTC)2, Cu2(BDC)2(DABCO), Cu2(BPDC)2(BPY) and Cu(BDC); ii)Catalytic studies of Cu3(BTC)2, Cu2(BDC)2(DABCO),

Cu2(BPDC)2(BPY) on C–C coupling reactions between amine compounds and terminal alkynes, catalytic studies of Cu(BDC) on C–N coupling reaction between α-hydroxyacetophenone and o-

phenylenediamine

CHAPTER 2 SYNTHESIS AND CHARACTERIZATION OF

Cu 3 (BTC) 2 , Cu 2 (BDC) 2 (DABCO), Cu 2 (BPDC) 2 (BPY), Cu(BDC)

2.1 Introduction

In this chapter, the synthesis, characterization methods, physicochemical properties of Cu3(BTC)2, Cu2(BDC)2(DABCO), Cu2(BPDC)2(BPY) and Cu(BDC) were studied

2.3 Results and discussions

2.3.1 Synthesis and characterization of Cu 3 (BTC) 2

 The synthesis yield was approximately 85% based on H3BTC

 The copper content in the Cu3(BTC)2 was 29% (ICP-MS)

 The BET surface areas of Cu3(BTC)2 were achieved approximately

1799 m2/g, the Langmuir surface areas were achieved approximately

2007 m2/g

 The thermal stability of Cu3(BTC)2 is over 300 oC (TGA)

 The PXRD pattern of the synthesized Cu3(BTC)2 was similar to the simulated pattern previously reported in the literature (Figure 2.2)

 The SEM micrograph indicated Cu3(BTC)2 exhibited a cubic octahedral morphology (Fig 2.4)

Figure 2.2 X-ray powder

diffractograms of the simulated

Cu3(BTC)2 (a) and the synthesized

Cu3(BTC)2 (b)

Figure 2.4 SEM micrograph

of the Cu3(BTC)2

2.3.2 Synthesis and characterization of Cu 2 (BDC) 2 (DABCO)

 The synthesis yield was approximately 66% based on H2BDC

 The copper content in the Cu2(BDC)2(DABCO) was 21.5% (ICP-MS)

 Langmuir surface areas of Cu2(BDC)2(DABCO) were achieved approximately 1174 m2/g

 The Cu2(BDC)2(DABCO) was stable up over 300 °C

Figure 2.8 X-ray powder diffractograms of the

simulated Cu2(BDC)2(DABCO) (a) and the

synthesized Cu2(BDC)2(DABCO) (b)

Figure 2.9 SEM micrograph of the

Cu2(BDC)2(DABCO)

 The PXRD pattern of the synthesized Cu2(BDC)2(DABCO) was in good accordance with the simulated pattern of the optimized plausible structure by using Cerius 2 (Fig 2.8)

 Figure 2.9 showed that SEM micrograph of Cu2(BDC)2(DABCO) revealed that well-shaped, high- quality cubic crystals were formed

2.3.3 Synthesis and characterization of Cu 2 (BPDC) 2 (BPY)

 The synthesis yield was approximately 66% based on H2BPDC

 The copper component in Cu2(BPDC)2(BPY) was 18% (ICP-MS)

 Langmuir surface areas of 1519 m2/g were achieved for the

Cu2(BPDC)2(BPY), BET surface areas were achieved 1082 m2/g

 TGA result indicated that the Cu2(BPDC)2(BPY) was stable up to over

300 °C

 PXRD pattern of the Cu2(BPDC)2(BPY) (Fig 2 14) showed the

presence of a sharp peak at 2θ = 6°, being consistent with the simulated

pattern of single-crystal previously reported by James and co-workers

 The SEM micrograph of the Cu2(BPDC)2(BPY) revealed that the formed crystals were well-shaped cubic (Fig 2.16)

Figure 2.14 X-ray powder diffractograms

of the simulated Cu2(BPDC)2(BPY) (a)

and the synthesized Cu2(BPDC)2(BPY) (b)

Figure 2.16 SEM micrograph

of the Cu2(BPDC)2(BPY)

2.3.4 Synthesis and characterization of Cu(BDC)

 The synthesis yield was approximately 66% based on H2BDC

 The copper content in the Cu(BDC) was 29% (ICP-MS)

 Langmuir surface areas of 616 m2

/g were achieved for the material

 TGA result indicated that the Cu(BDC) was stable up to over 300 °C

 The PXRD pattern of the Cu(BDC) was also similar to the simulated pattern previously reported in the literature (Fig 2.20)

 The SEM micrograph indicated the formation of the cubic microcrystals of the Cu(BDC)

1.3

Figure 2.20 X-ray powder diffractograms of

the simulated Cu(BDC) (a) and the

synthesized Cu(BDC) (b)

Figure 2.22 SEM micrograph

of the Cu(BDC)

2.4 Conclusion

The four Cu-MOFs such as Cu3(BTC)2, Cu2(BDC)2(DABCO),

Cu2(BPDC)2(BPY) and Cu(BDC) were successfully synthesized and characterized by PXRD, FT-IR, TGA, H2TPR, ICP-MS and nitrogen physisorption measurements

CHAPTER 3 CATALYTIC STUDIES OF Cu 3 (BTC) 2 ,

Cu 2 (BDC) 2 (DABCO), Cu 2 (BPDC) 2 (BPY), Cu(BDC) ON C–C AND C–N COUPLING REACTIONS

3.1 Introduction

 Cu3(BTC)2, Cu2(BDC)2(DABCO), Cu2(BPDC)2(BPY) and Cu(BDC) exhibited high activity for many reactions due to their unsaturated open

metal sites

 In this chapter, the catalytic performance of Cu3(BTC)2,

Cu2(BDC)2(DABCO), Cu2(BPDC)2(BPY) and Cu(BDC) on the C–C, C–N coupling reactions will be discussed (Scheme 3 1 and Scheme

3.2)

Scheme 3.1 The synthesis of propargylamines

Scheme 3.2 The synthesis of quinoxaline

1.4 3.2 Experimental

Catalytic studies of Cu3(BTC)2 on C–C coupling reaction from

N,N-dimethylanilines and terminal alkynes (reaction 1); Catalytic studies of

terminal alkynes (reaction 2); Catalytic studies of Cu2(BPDC)2(BPY) on C–C coupling reaction from Tetrahydroisoquinoline, benzaldehydes and terminal

alkynes (reaction 3); Catalytic studies of Cu(BDC) on C–N coupling reaction from α-hydroxyacetophenone and phenylenediamine (reaction 4)

The reaction conversions were monitored by withdrawing aliquots from the reaction mixture at different time intervals, quenching with water (1 ml), drying over anhydrous Na2SO4, analyzing by Gas chromatographic (GC) with reference to inernal standard All major products from four reactions were confirmed by 1H NMR and 13C NMR

3.3 Results and discussions

3.3.1 Catalytic studies of Cu 3 (BTC) 2 on C–C coupling reaction (1)

Scheme 3.3 The direct oxidative C-C coupling reaction between

N,N-dimethylaniline and phenylacetylene using Cu3(BTC)2 as catalyst

 All optimized synthetic conditions of reaction 1 between

N,N-dimethylaniline and phenylacetylene are summaried in Table 3.2

Reaction conditions Results (Reaction conversion (%)) Temperature RT (0), 100 °C (56), 110 °C (76), 120 °C