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Org. Synth. 2020, 97, 157-171

DOI: 10.15227/orgsyn.097.0157

Synthesis of α-Bromoacetyl MIDA Boronate

Submitted by C. Frank Lee,¹ Chieh-Hung Tien,¹ Shinya Adachi, and Andrei K. Yudin^2*

Checked by Zhaobin Han and Kuiling Ding

1. Procedure (Note 1)

A. Oxiran-2-yl MIDA boronate (2). An oven-dried 2000-mL single-necked, round-bottomed flask equipped with a 6.5 cm Teflon-coated magnetic stir bar is charged with vinyl MIDA boronate (1) (15.0 g, 82.0 mmol, 1 equiv) (Note 2) and acetonitrile (820 mL, 0.1 M) (Note 3) under ambient atmosphere. To this solution is added 3-chloroperbenzoic acid (≤77% mCPBA, 40.4 g, 180.4 mmol, 2.2 equiv) (Note 4) in one portion. The flask is then equipped with a condenser (Figure 1A). The resulting mixture is stirred at 35 °C for 26 h in a silicon oil bath under ambient atmosphere (Note 5). The resulting mixture is cooled to room temperature with stirring (Note 6) (Figure 1B); the volatiles are removed in vacuo (30 °C, 20 mmHg). Diethyl ether (1500 mL) (Note 7) is then added to the reaction flask and stoppered with a rubber sleeve stopper septum. The resulting suspension is stirred at room temperature for 16 h (Note 6). The suspension is filtered through a medium fritted funnel where the filter cake is broken up and washed further with diethyl ether (450 mL) (Note 7). The solids are collected via vacuum filtration to afford the desired product, oxiran-2-yl MIDA boronate (2) (16.0 g, 98%) (Notes 8, 9, and 10) as a colorless solid.

Figure 1. A) Reaction mixture after addition of mCPBA; B) Reaction mixture cooling to room temperature after 26 h of stirring at 35 °C

B. (2-Bromo-1-hydroxyethyl)MIDA boronate (3). In an oven-dried 2000-mL single-necked, round-bottomed flask equipped with a 6.5 cm Teflon-coated magnetic stir bar is charged with oxiran-2-yl MIDA boronate (2) (15.6 g, 78.4 mmol, 1 equiv) and acetonitrile (780 mL, 0.1 M) (Note 2) under ambient atmosphere. To the suspension is added LiBr (34.0 g, 392.0 mmol, 5.0 equiv) (Note 11) and glacial acetic acid (67.3 mL, 1180 mmol, 15.0 equiv) (Note 12) at room temperature (Note 6) where the flask is equipped with an adapter (19/22) connected to a manifold. The resulting mixture is allowed to stir at room temperature for 2.5 h (Note 6) under ambient atmosphere (Figure 2). The solvent is removed in vacuo (30 °C, 20 mmHg) and the crude residue is dissolved in EtOAc (1000 mL) (Note 13) and acetone (300 mL) (Note 14). The mixture is washed with deionized water (1 x 500 mL), then separated. The aqueous layer is extracted with EtOAc/acetone (3 x 650 mL, 5:1.5 EtOAc/acetone ratio) (Notes 13 and 14). The combined organic phase is dried over anhydrous Na₂SO₄ (250 g) (Note 15), filtered, and concentrated in vacuo (30 °C, 20 mmHg). The crude product (2-Bromo-1-hydroxyethyl)MIDA boronate (3) (20.5 g, 94% crude yield) is carried over to the next step without further purification (Notes 16 and 17).

Figure 2. Reaction mixture after stirring at room temperature for 2.5 h

C. (2-Bromoacetyl)MIDA boronate (4). In an oven-dried 2000-mL single-necked, round-bottomed flask equipped with a 6.5 cm Teflon-coated magnetic stir bar is charged with crude (2-Bromo-1-hydroxyethyl)MIDA boronate (3) (20.1 g, 71.6 mmol, 1 equiv), acetonitrile (360 mL), and ethyl acetate (360 mL, 0.1 M combined) (Notes 3 and 13). The suspension is allowed to stir at room temperature (Note 6) for 20 min in order for 3 to completely dissolve in solution. Upon solvation, the mixture is cooled to 0 °C (Note 18) and stirred at 0 °C for 10 min. To the solution is added Dess-Martin periodinane (DMP) (36.5 g, 86.0 mmol, 1.2 equiv) (Note 19) in one portion (Figure 3A). The resulting suspension mixture is equipped with an adapter (19/22) connected to a manifold and is allowed to stir at 0 °C (Note 18) for 1 h. After stirring for 1 h, the reaction suspension is diluted with a 1:1 mixture of ethyl acetate/acetonitrile (720 mL) (Notes 3 and 13), whereby the liquid phase is slowly decanted through a Büchner funnel by vacuum filtration into a 2000-mL round-bottomed flask (Note 20). The volatiles of the filtrate are removed in vacuo (30 °C, 20 mmHg) to afford a yellow residue (Note 21). The resulting residue is suspended with ethyl acetate (600 mL) (Note 13) and a 6.5-cm Teflon-coated magnetic stir bar and stirred at room temperature (Note 6) for 0.5 h under ambient atmosphere. The mixture is filtered through a pad of Celite (Note 22) via vacuum filtration into a 1000-mL round-bottomed flask (Note 23). The volatiles of the filtrate are removed in vacuo (30 °C, 20 mmHg) and to the resulting residue is added a 1:1 mixture of EtOAc/acetone (60 mL) (Note 13 and 14) and a 6.5 cm Teflon-coated stir bar. The mixture is sonicated and stirred to afford a thick suspension. Diethyl ether (600 mL) (Note 7) is added over a period of 5 min, then the mixture is stirred at room temperature for an additional 10 min (Note 6). The suspension is filtered through a medium fritted funnel via vacuum filtration where the resulting filter cake is allowed to dry under vacuum (Note 24) The filter cake is then collected and added to a 3000-mL round-bottomed flask equipped with a 6.5 cm Teflon-coated stir bar and charged with ethyl acetate (300 mL) and dichloromethane (500 mL) (Notes 13 and 25). The suspension is allowed to stir for 0.5 h at room temperature (Note 6) under ambient atmosphere. toluene (2000 mL) (Note 26) is then added to the stirring suspension over 5 min at which point the flask is equipped with a rubber sleeve stopper septum and stirred for 16 h at room temperature (Note 6). The suspension is filtered through a medium fritted funnel by vacuum filtration, then the filter cake is collected and allowed to dry under vacuum (Note 27). The resulting solids are then added to a 2000-mL round-bottomed flask equipped with a 6.5 cm Teflon-coated stir bar. The flask is charged with acetone (500 mL) (Note 14), equipped with a rubber sleeve stopper septum, then cooled to 0 °C (Note 18) and stirred for 1 h. After 1 h, the suspension is filtered through a pad of Celite (Note 18) by vacuum filtration into a 1000-mL round-bottomed flask. The volatiles of the filtrate are removed in vacuo (20 °C, 10 mmHg) to obtain the desired product, (2-Bromoacetyl)MIDA boronate (4) (8.9 g, 45%), as a colorless solid (Notes 28, 29, and 30) (Figure 3B).

Figure 3. A) Reaction mixture after addition of DMP; B) Final product (4)

2. Notes

1. Prior to performing each reaction, a thorough hazard analysis and risk assessment should be carried out with regard to each chemical substance and experimental operation on the scale planned and in the context of the laboratory where the procedures will be carried out. Guidelines for carrying out risk assessments and for analyzing the hazards associated with chemicals can be found in references such as Chapter 4 of "Prudent Practices in the Laboratory" (The National Academies Press, Washington, D.C., 2011; the full text can be accessed free of charge at https://www.nap.edu/catalog/12654/prudent-practices-in-the-laboratory-handling-and-management-of-chemical. See also "Identifying and Evaluating Hazards in Research Laboratories" (American Chemical Society, 2015) which is available via the associated website "Hazard Assessment in Research Laboratories" at https://www.acs.org/content/acs/en/about/governance/committees/chemicalsafety/hazard-assessment.html. In the case of this procedure, the risk assessment should include (but not necessarily be limited to) an evaluation of the potential hazards associated with vinyl MIDA boronate, acetonitrile, 3-chloroperbenzoic acid, silicon oil, diethyl ether, glacial acetic acid, ethyl acetate, acetone, deionized water, anhydrous sodium sulfate_4, Dess-Martin periodinane (DMP), Celite, dichloromethane, lithium bromide, glacial acetic acid, toluene, and mesitylene. Reactions and subsequent operations involving peracids and peroxy compounds should be run behind a safety shield.

2. Vinyl MIDA boronate (1) was purchased from Sigma-Aldrich (97%) and was used as received. Vinyl MIDA boronate (1) can also be separately synthesized on scale using the procedure reported by Burke and co-workers.³

3. Acetonitrile was purchased from Caledon Laboratory Chemicals (99.9% pure) and was used as received. The checkers purchased acetonitrile (99+%, extra pure) from Acros Organics and used it as received.

4. 3-Chloroperbenzoic acid (≤77%) was purchased from Sigma-Aldrich and was used as received. An excess of 2.2 equiv was used in order for the reaction to go to completion. The use of fewer equivalents of m-CPBA resulted in incomplete conversion as well as diminished yield of the desired product.

5. Silicon oil was purchased from Sigma-Aldrich and was used as received. The checkers purchased silicon oil from Alfa Aesar and used it as received.

6. Room temperature was monitored to be 20~25 °C during the course of experiments. The internal reaction temperature was dropped to 15 °C from 25 °C after the addition of 3-chloroperbenzoic acid.

7. Diethyl ether was purchased from Fisher (99.0% pure) and was used as received. The checkers purchased diethyl ether (≥ 99.5%) from Tansoole and used it as received.

8. A second reaction on half scale provided 8.0 g (98%) of the product 2.

9. Spectroscopic analysis of 2: ¹H NMR pdf (400 MHz, Acetonitrile-d₃) δ: 2.23 (br s, 1H), 2.57 (dd, J = 5.6 Hz, 3.6 Hz, 1H), 2.80 (t, J = 5.6 Hz, 1H), 3.06 (s, 3H), 3.79 (d, J = 16.8 Hz, 1H), 3.85-4.03 (m, 3H); ¹³C NMR pdf (100 MHz, Acetonitrile-d₃) δ: 45.1, 47.1, 62.7, 62.9, 168.5, 169.6; ¹¹B NMR pdf (192 MHz, Acetonitrile-d₃) δ: 10.1. Carbon atoms exhibiting significant line broadening brought about by boron substituents were not reported (quadrupolar relaxation). HRMS of 2: [ESI-MS] (M+Na⁺) m/z calculated for C₇H₁₀BNO₅Na: 222.0544; m/z found = 222.0542. mp 195-197 °C. IR (film): 1746, 1451, 1284, 1239, 1169, 1034, 955, 901, 852, 605 cm^-1.

10. The purity of 2 was determined to be 96% by quantitative NMR pdf spectroscopy with mesitylene (97%) as the internal standard (a mixture of 3.4 mg of 2 and 4.3 mg of mesitylene was used to determine purity). Mesitylene (97%) was purchased from Sigma-Aldrich and was used as received.

11. Lithium bromide was purchased from Sigma-Aldrich (≥99%) and was used as received. The checkers purchased lithium bromide (99%) from Alfa Aesar and used it as received. A large excess of LiBr (5.0 equiv) was used in order to significantly reduce the reaction time to the order of hours instead of days. This effect was noted in the initial report by Bajwa and Anderson.⁴

12. Glacial acetic acid was purchased from Fisher (99.7% pure) and was used as received. The checkers purchased glacial acetic acid (99.5%) from Tokyo Chemical Industry Co., Ltd. and used it as received. The use of acetic acid was essential for the conversion to the halohydrin. It was proposed that the reaction involves a reversible epoxide ring opening and that acetic acid drives the reaction to completion via protonation of the intermediate alkoxide.⁴

13. Ethyl acetate was purchased from Fisher (99.9% pure) and was used as received. The checkers purchased ethyl acetate (99.8%) from Tansoole and used it as received.

14. Acetone was purchased from Fisher (99.7% pure) and was used as received. The checkers purchased acetone (99.5%) from Tansoole and used it as received.

15. sodium sulfate (anhydrous) was purchased from Caledon Laboratory Chemicals (granular, 99.0% pure) and was used as received. The checkers purchased sodium sulfate (anhydrous, 99%) from Tansoole and used it as received.

16. A second reaction on half scale provided 10.3 g (94%) of the product 3.

17. Spectroscopic analysis of crude 3: ¹H NMR pdf (400 MHz, Acetonitrile-d₃) δ: 3.03 (s, 3H), 3.54 (s, 2H), 3.78-3.83 (m, 1H), 3.86 (s, 1H), 3.90-4.04 (m, 3H); ¹¹B NMR pdf (192 MHz, Acetonitrile-d₃) δ: 10.0. HRMS of 3: [ESI] (M+Na⁺) m/z calculated forC₇H₁₁BBrNNaO₅: 301.9806; m/z found 301.9803. mp 175-178 °C. IR (film): 1773, 1461, 1332, 1279, 1192, 1106, 1025, 985, 897, 861, 642 cm^-1. No purification was determined to be necessary as indicated by analysis of the crude material's ¹H NMR spectrum; thus, the crude material 3 was carried onto the next step and no purity analysis was obtained.

18. In order to cool to 0 °C, the solution in the round-bottomed flask was immersed in an ice/water bath and stirred for 10 min.

19. Dess-Martin periodinane (DMP) was purchased from Combi-Blocks (95% pure) and it was used as received. The checkers purchased DMP (>95%) from Tokyo Chemical Industry Co., Ltd. and used it as received. DMP can also be prepared on scale following an Organic Syntheses procedure reported by Boeckman, Jr. and co-workers.⁵

20. This filtration step was included to remove any unreacted and undissolved DMP. Using a medium fritted funnel at this point will cause the filtration apparatus to clog. The filtrate at this point remains a suspension. The final compound (4) is unstable under aqueous conditions; thus, standard aqueous workup to remove Dess-Martin periodinane by-products could not be used.

21. The crude residue should be a thick oil as the acetic acid by-product has not been removed at this point. This increases the solubility of the product and by-product in the next step.

22. Celite (technical) was purchased from ACP Chemicals, Inc. and it was used as received. The checkers purchased Celite (99.5%) from Alfa Aesar and used it as received.

23. This filtration step was included to partially separate insoluble DMP by-products.

24. The crude solid is a mixture of product and DMP by-product.

25. Dichloromethane was purchased from Caledon Laboratory Chemicals (99.5% pure, stabilized with 50 ppm 2-methyl-2-butene) and it was used as received. The checkers purchased dichloromethane (99.8%) from Acros Organics and used it as received.

26. Toluene was purchased from Fisher (99.9% pure) and it was used as received. The checkers purchased toluene (99.8%) from Tansool and used it as received.

27. The crude solid is a mixture of product and 2-iodosobenzoic acid (IBA).

28. A second reaction on half-scale provided 4.3 g (43%) of the product 4.

29. Spectroscopic analysis of 4: ¹H NMR pdf (400 MHz, Acetonitrile-d₃) δ: 2.86 (s, 3H), 3.94 (d, J = 17.2 Hz, 2H), 4.08 (d, J = 17.2 Hz, 2H), 4.42 (s, 2H); ¹³ C NMR pdf (100 MHz, Acetonitrile-d₃) δ: 42.4, 47.8, 63.1, 168.7; ¹¹B NMR pdf (192 MHz, Acetonitrile-d₃) δ: 4.4. Carbon atoms exhibiting significant line broadening brought about by boron substituents were not reported (quadrupolar relaxation). HRMS of 4: [DART-TOF] (M+H⁺) m/z calculated for C₇H₁₀¹⁰BBrNO₅: 276.9866; m/z found = 276.9868. mp 155-157 °C. IR (film): 1767, 1679, 1456, 1338, 1267, 1193, 1052, 991, 896, 823, 615 cm^-1.

30. The purity of 4 was determined to be >95.0% by quantitative NMR pdf spectroscopy with mesitylene (97%) as the internal standard (a mixture of 2.1 mg of 4 and 4.4 mg of mesitylene was used for purity analysis).

Working with Hazardous Chemicals

The procedures in Organic Syntheses are intended for use only by persons with proper training in experimental organic chemistry. All hazardous materials should be handled using the standard procedures for work with chemicals described in references such as "Prudent Practices in the Laboratory" (The National Academies Press, Washington, D.C., 2011; the full text can be accessed free of charge at http://www.nap.edu/catalog.php?record_id=12654). All chemical waste should be disposed of in accordance with local regulations. For general guidelines for the management of chemical waste, see Chapter 8 of Prudent Practices.

In some articles in Organic Syntheses, chemical-specific hazards are highlighted in red "Caution Notes" within a procedure. It is important to recognize that the absence of a caution note does not imply that no significant hazards are associated with the chemicals involved in that procedure. Prior to performing a reaction, a thorough risk assessment should be carried out that includes a review of the potential hazards associated with each chemical and experimental operation on the scale that is planned for the procedure. Guidelines for carrying out a risk assessment and for analyzing the hazards associated with chemicals can be found in Chapter 4 of Prudent Practices.

The procedures described in Organic Syntheses are provided as published and are conducted at one's own risk. Organic Syntheses, Inc., its Editors, and its Board of Directors do not warrant or guarantee the safety of individuals using these procedures and hereby disclaim any liability for any injuries or damages claimed to have resulted from or related in any way to the procedures herein.

3. Discussion

Organoboron compounds have become increasingly relevant in synthesis and drug discovery as they represent key intermediates in accessing complex small molecules/heterocycles and unique structural motifs.⁶ However, methods involving the borylation of heterocycles continue to be a challenge in terms of obtaining regioselective control of the transformation. The borylation of preformed heterocycles typically involve lithiation protocols,⁷ transition metal-catalyzed reactions,^8,9 and electrophilic borylation methods.^10,11 Not only do these protocols present regioselectivity challenges, but they also require elaborate and/or harsh reaction conditions. In an effort to construct borylated heterocycles in an inward fashion through a condensation/substitution strategy, our group has reported the synthesis of α-Bromoacetyl MIDA Boronate (MIDA = N-methyliminodiacetic acid) as a synthetically useful boron-containing building block for the construction of previously inaccessible and uniquely substituted borylated heterocycles.¹²

α -Bromoacetyl MIDA boronate was synthesized by the epoxidation of commercially available vinyl MIDA boronate (1) with mCPBA, furnishing the corresponding oxiran-2-yl MIDA boronate (2) after trituration of the crude material with diethyl ether.³ The epoxide was regioselectively ring-opened with lithium bromide in the presence of acetic acid⁴ at room temperature after 2.5 h to afford the desired (2-Bromo-1-hydroxyethyl)MIDA boronate (3). After aqueous workup and concentration, the crude product of 3 was directly carried onto the following oxidation step with Dess-Martin periodinane, ultimately yielding α-Bromoacetyl MIDA Boronate (4) in good yield. Due to the instability of 4 in aqueous conditions, aqueous workup to remove Dess-Martin periodinane byproducts could not be used. Instead, the desired building block was purified by a series of filtration/trituration protocols with diethyl ether, ethyl acetate, dichloromethane, and toluene to obtain the final product.

The α-bromoacetyl MIDA boronate building block has been shown to be amenable towards the synthesis of C2-borylated imidazopyridines and indolizines in a regiochemically controlled fashion, with downstream construction of novel boron-containing bis(heteroaryl) motifs. The C2-borylated heterocycles shown in Scheme 1 are unique in that they are not known to our knowledge with respect to the position of the boron moiety. They can also be applied towards cross-coupling reactions, conversion to the corresponding organotrifluoroborate potassium salt, as well as a condensation driven assembly of bis(heteroaryl) motifs in indolizyl-oxadiazaboroles and indolizyl-triazaboroles in excellent yields.

Scheme 1. Synthetic Applications of α-Bromoacetyl MIDA Boronate

References and Notes

These authors contributed equally.
Davenport Research Laboratories, Department of Chemistry, University of Toronto, Toronto, ON, Canada. Email: andrei.yudin@utoronto.ca (A.K.Y., ORCID: 0000-0003-3170-9103). The authors are grateful to the Natural Science and Engineering Research Council (NSERC), the Canadian Foundation for Innovation, Project Number 19119, for funding, and the Ontario Research Fund for funding of the Centre for Spectroscopic Investigation of Complex Organic Molecules and Polymers. We are grateful to the University of Toronto, the Government of Ontario (OGS & QEII), and NSERC (PGS-D) for financial support (C.F.L.) as well as the Connaught Fund (C.-H.T., ORCID: 0000-0002-7859-5804).
Uno, B. E.; Gillis, E. P.; Burke, M. D. Tetrahedron 2009, 65, 3130-3138.
Bajwa, J. S.; Anderson, R. C. Tetrahedron Lett. 1991, 32, 3021-3024.
Boeckman, Jr., R. K.; Shao, P.; Mullins, J. J. Org. Synth. 2000, 77¸ 141-152.
Synthesis and Application of Organoboron Compounds, Vol. 49 (Eds: Fernández, E.; Whiting, A.), Springer International Publishing, 2015.
Billingsly, K.; Buchwald, S. L. J. Am. Chem. Soc. 2007, 129, 3358-3366.
Ishiyama, T.; Takagi, I.; Yonekawa, Y.; Hartwig, N.; Miyaura, N. Adv. Synth. Catal. 2003, 345, 1103-1106.
Preshlock, S. M.; Plattner, D. L.; Maligres, P. E.; Krska, S. E.; Maleczka Jr.; R. E.; Smith III, M. R. Angew. Chem. Int. Ed. 2013, 52, 12915-12919.
Del Grosso, A.; Singleton, P. J.; Muryn, C. A.; Ingleson, M. J. Angew. Chem. Int. Ed. 2011, 47, 12459-12461.
Bagutski, V.; Del Grosso, A.; Carrillo, J. A.; Cade, I. A.; Heml, M. D.; Lawson, J. R.; Singleton, P. J.; Solomon, S. A.; Marcelli, T.; Ingleson, M. J. J. Am. Chem. Soc. 2013, 135, 474-487.
Adachi, S.; Liew, S. K.; Lee, C. F.; Lough, A.; He, Z.; St. Denis, J. D.; Poda, G.; Yudin, A. K. Org. Lett. 2015, 17, 5594-5597.

Appendix
Chemical Abstracts Nomenclature (Registry Number)

Vinyl MIDA boronate: Vinylboronic acid MIDA ester; (1104636-73-8)

3-Chloroperbenzoic acid; (937-14-4)

LiBr: Lithium bromide; (7550-35-8)

DMP: Dess-Martin periodinane; (87413-09-0)

	C. Frank Lee grew up in Vancouver, B.C. Canada. He obtained his Bachelor's degree in chemistry in 2013 from Queen's University in Kingston, O.N. Canada, where he worked on natural product synthesis and transition metal-catalyzed method development under the supervision of Professor Victor Snieckus. He then started his graduate studies at the University of Toronto where he completed his Ph.D. degree in the laboratory of Professor Andrei K. Yudin in 2018. His research focused on the development of robust organoboron building blocks for the synthesis of nitrogen-containing heterocycles and application toward the construction of kinase inhibitors.
	Chieh-Hung Tien was born and raised in Kaohsiung, Taiwan. He received both his B.Sc. Hons. and M.Sc. in chemistry from Dalhousie University, where he worked under the supervision of Professor Alexander Speed. Tien worked on the synthesis of organomagnesium reagents and heterocyclic main group catalysts during the course of his studies at Dalhousie University. Tien joined the group of Professor Andrei K. Yudin at the University of Toronto in 2018 as a Ph.D. student with interests in the synthesis of small molecules and methodology development.
	Shinya Adachi was born and grew up in Japan. He received his Ph.D. in 2010 under the guidance of Professor Toshiro Harada at the Kyoto Institute of Technology. He subsequently spent two years working at North Dakota State University under the direction of Professor Mukund P. Sibi. He then joined the Yudin group, where he worked on the synthetic applications of boryl aldehydes and aziridine aldehydes. He is currently a postdoctoral fellow in the Shibasaki group at Institute of Microbial Chemistry in Japan.
	Professor Andrei K. Yudin obtained his B.Sc. at Moscow State University and his Ph.D. at the University of Southern California under the direction of Professors G. K. Surya Prakash and George A. Olah. He subsequently took up a postdoctoral position with Professor K. Barry Sharpless at the Scripps Research Institute. In 1998, he started his independent career at the University of Toronto. He received early tenure, becoming an Associate Professor in 2002, and received an early promotion to the rank of a Full Professor in 2007. The main focus of the Yudin group is to develop a bridge between basic chemistry research and drug discovery. In addition to significant fundamental discoveries, his lab has made tangible contributions to process chemistry.
	Dr. Zhaobin Han received his B.S. degree in chemistry from Nanjing University in 2003. He received his Ph.D. degree from Shanghai Institute of Organic Chemistry under the supervision of Prof. Kuiling Ding and Prof. Xumu Zhang in 2009, working on development of novel chiral ligands for asymmetric catalysis. Now he is an associate professor in the same institute and his current research interests focus on the development of efficient catalytic methods based on homogeneous catalysis.

Notes

References/EndNotes

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