Iridium-catalyzed highly efficient chemoselective reduction of aldehydes in water using formic acid as the hydrogen source

Iridium-catalyzed highly efficient chemoselective reduction of aldehydes in water using formic acid as the hydrogen source

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC01289F, Paper

Zhanhui Yang, Zhongpeng Zhu, Renshi Luo, Xiang Qiu, Ji-tian Liu, Jing-Kui Yang, Weiping Tang
A highly efficient iridium catalyst is developed for the chemoselective reduction of aldehydes to alcohols in water, using formic acid as a reductant.

From the journal:

Green Chemistry

Iridium-catalyzed highly efficient chemoselective reduction of aldehydes in water using formic acid as the hydrogen source

Zhanhui Yang,ab  Zhongpeng Zhu,ac  Renshi Luo,ad  Xiang Qiu,a  Ji-tian Liu,a  Jing-Kui Yangc  and Weiping Tang*ae 

*Corresponding authors

aSchool of Pharmacy, University of Wisconsin–Madison, Madison, USA
E-mail: weiping.tang@wisc.edu

bFaculty of Science, Beijing University of Chemical Technology, Beijing, P. R. China

cSchool of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, P. R. China

dSchool of Pharmacy, Gannan Medical University, Ganzhou, P. R. China

eDepartment of Chemistry, University of Wisconsin–Madison, Madison, USA

Abstract

A water-soluble highly efficient iridium catalyst is developed for the chemoselective reduction of aldehydes to alcohols in water. The reduction uses formic acid as the traceless reducing agent and water as a solvent. It can be carried out in air without the need for inert atmosphere protection. The products can be purified by simple extraction without any column chromatography. The catalyst loading can be as low as 0.005 mol% and the turn-over frequency (TOF) is as high as 73800 mol mol−1 h−1. A wide variety of functional groups, such as electron-rich or deficient (hetero)arenes and alkenes, alkyloxy groups, halogens, phenols, ketones, esters, carboxylic acids, cyano, and nitro groups, are all well tolerated, indicating excellent chemoselectivity.

http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C7GC01289F?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

4-Methoxybenzyl alcohol (2a)2 . Yellowish oil. Yield: 273 mg, 99%.

1H NMR (400 MHz, CDCl3) δ 7.23 (d, J = 8.8 Hz, 2H), 6.85 (d, J = 8.7 Hz, 2H), 4.52 (s, 2H), 3.76 (s, 3H).

13C NMR (101 MHz, CDCl3) δ 159.07, 133.23, 128.63, 113.89, 64.73, 55.30, 55.26.

Zhanhui Yang

School of Pharmacy, University of Wisconsin–Madison, Madison, USA
E-mail:weiping.tang@wisc.edu

School of Pharmacy
UNIVERSITY OF WISCONSIN - MADISON

Beijing University of Chemical... , Beijing

Organic Chemistry, Green Chemistry, Catalysis

PhD student

Beijing University of Chemical Technology

Organic Chemistry

Beijing, China

School of Pharmacy, University of Wisconsin–Madison, Madison, USA

4-Methoxybenzyl alcohol

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Efficient and Stereoselective Syntheses of Isomerically Pure 4-Aminotetrahydro-2H-thiopyran 1-Oxide Derivatives

 

trans-4-Aminotetrahydro-2H-thiopyran 1-Oxide Methanesulfonate (trans-3d-MsOH)

Compound ...................afforded trans-3d-MsOH (20 g, 68%) as a white crystalline solid.

1H NMR (300 MHz, DMSO-d6) δ 1.60–1.76 (2H, m), 2.16–2.29 (2H, m), 2.31 (3H, s), 2.68–2.81 (2H, m), 3.13–3.23 (2H, m), 3.27–3.35 (1H, m), 7.86 (3H, brs).

 

13C NMR (75 MHz, D2O) δ 24.98, 38.51, 46.18, 46.84.

 

LCMS m/z calcd for C5H11NOS: 133.06, found 134.1 [M + H].

 

Anal. Calcd for C6H15NO4S2: C, 31.43; H, 6.59; N, 6.11. Found: C, 31.62; H, 6.48; N, 6.19. mp 214–216 °C.

 

cis-4-Aminotetrahydro-2H-thiopyran 1-Oxide Hydrochloride (cis-4d-HCl)

A mixture of .................... to afford cis-4d-HCl (22.5 g, 62%) as a white crystalline solid.

1H NMR (400 MHz, DMSO-d6) δ 1.81–2.00 (2H, m), 2.06–2.24 (2H, m), 2.73 (2H, td, J = 13.6, 3.2 Hz), 2.90–3.01 (2H, m), 3.21 (1H, brs), 8.19 (3H, brs).

 

13C NMR (75 MHz, D2O) δ 19.80, 42.94, 47.34.

 

LCMS m/z calcd for C5H11NOS: 133.06, found 134.1 [M + H]. Anal. Calcd for C5H12NClOS: C, 35.39; H, 7.13; N, 8.26. Found: C, 35.28; H, 6.87; N, 8.26. mp 230–232 °C.

 

Efficient and Stereoselective Syntheses of Isomerically Pure 4-Aminotetrahydro-2H-thiopyran 1-Oxide Derivatives

Ryo Mizojiri*† , Kazuaki Takami†, Tatsuya Ito‡, Hiroyuki Maeda‡, Mitsuhisa Yamano‡, and Tetsuji Kawamoto*†

† Research, Takeda Pharmaceutical Company Ltd., Fujisawa, Kanagawa 251-8555, Japan

‡ Pharmaceutical Sciences, Takeda Pharmaceutical Company Ltd., Yodogawa-ku, Osaka 532-8686, Japan

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.7b00147

 

*E-mail: ryo.mizojiri@takeda.com. Phone: +81-466-32-1058 (R.M.)., *E-mail: tetsuji.kawamoto@takeda.com. Phone: +81-466-32-1193 (T.K.).

http://pubs.acs.org/doi/suppl/10.1021/acs.oprd.7b00147

Efficient and stereoselective syntheses of isomerically pure 4-aminotetrahydro-2H-thiopyran 1-oxide derivatives have successfully been achieved. Isomerically pure (4-nitrophenyl)sulfonyltetrahydro-2H-thiopyran 1-oxides were identified by X-ray crystallographic analyses, and isomerically pure sulfoxide derivatives were characterized by 1H NMR. An oxidation reaction of tert-butyl(4-nitrophenyl)sulfonyl(tetrahydro-2H-thiopyran-4-yl)carbamate with Oxone provided steric control, affording its trans sulfoxide with high efficiency and selectivity. From the obtained trans sulfoxide derivatives, cis sulfoxide derivatives were synthesized conveniently by a hydrogen chloride catalyzed isomerization.

 

Tropylium salts as efficient organic Lewis acid catalysts for acetalization and transacetalization reactions in batch and flow

Tropylium salts as efficient organic Lewis acid catalysts for acetalization and transacetalization reactions in batch and flow

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC01519D, Communication

D. J. M. Lyons, R. D. Crocker, D. Enders, T. V. Nguyen
Tropylium salts were reported as organic-Lewis acids to efficiently catalyze acetalization reactions in batch and flow.

• 
• From the journal:
  

  Green Chemistry

Tropylium salts as efficient organic Lewis acid catalysts for acetalization and transacetalization reactions in batch and flow

 

D. J. M. Lyons,a  R. D. Crocker,a  D. Endersb  and  T. V. Nguyen*a 

Author affiliations

*Corresponding authors

aSchool of Chemistry, University of New South Wales, NSW 2052 Sydney, Australia
E-mail:t.v.nguyen@unsw.edu.au

bInstitute of Organic Chemistry, RWTH Aachen University, Aachen D52074, Germany

Abstract

Acetalization reactions play significant roles in the synthetically important masking chemistry of carbonyl compounds. Herein we demonstrate for the first time that tropylium salts can act as organic Lewis acid catalysts to facilitate acetalization and transacetalization reactions of a wide range of aldehyde substrates. This metal-free method works efficiently in both batch and flow conditions, prompting further future applications of tropylium organocatalysts in green synthesis.

http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C7GC01519D?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

1-(Diethoxymethyl)-4-methylbenzene (4a):

Prepared according to the general procedure from p-tolualdehyde and triethylorthoformate to yield the title compound as a colourless oil (99 mg, 0.50 mmol, quant. yield). 4a

1 H NMR (400 MHz, CDCl3) δ 7.38 (d, J = 8.1 Hz, 2H), 7.18 (d, J = 7.9 Hz, 2H), 5.50 (s, 1H), 3.59 (ddq, J = 35.4, 9.5, 7.1 Hz, 4H), 2.37 (s, 3H), 1.25 (t, J = 7.1 Hz, 6H) ppm;

13C NMR (101 MHz, CDCl3) δ 138.0, 136.3, 128.9, 126.64, 101.7, 61.0, 21.3, 15.3 ppm;

IR (KBr) 2973, 2880, 2327, 2102, 1909, 1740, 1448 cm-1 ;

ESI-MS Anal. Calcd. for 217.1199 C12H18O2Na, found 217.1195

1H NMR

1 H NMR (400 MHz, CDCl3) δ 7.38 (d, J = 8.1 Hz, 2H), 7.18 (d, J = 7.9 Hz, 2H), 5.50 (s, 1H), 3.59 (ddq, J = 35.4, 9.5, 7.1 Hz, 4H), 2.37 (s, 3H), 1.25 (t, J = 7.1 Hz, 6H) ppm;

13c nmr

13C NMR (101 MHz, CDCl3) δ 138.0, 136.3, 128.9, 126.64, 101.7, 61.0, 21.3, 15.3 ppm;

School of Chemistry

Science

Vinh Nguyen

BE (Hon 1, UNSW), Ph.D (ANU), MRACI CChem

Lecturer and DECRA fellow

Contact details

Phone: +61-2-9385 6167
Email: t.v.nguyen@unsw.edu.au

Office

Room 217 Dalton Building (F12)

School of Chemistry - UNSW

Research Group Website

Vinh Nguyen's group website

• Biographical Details
• Research interests
• Selected publications

• Interested in joining the group?
• Group website

 

Biographical Details

Dr. Vinh Nguyen (also known as: Thanh Vinh Nguyen or Thanh V. Nguyen on academic publication) was born in Vietnam. After high school, he went to Sydney, Australia to study industrial chemistry at University of New South Wales. He then moved to undertake his PhD in organic chemistry with Professor Michael Sherburn at the Australian National University, Canberra. He had worked to develop new synthetic methodologies for application in natural product synthesis and worked on the design and synthesis of enormoussynthetic host molecules for drug-delivery modelling. After graduating in 2010, he came to work on organocatalysis in Professor Dieter Enders group at the Institute of Organic Chemistry, RWTH Aachen, Germany under the auspices of an Alexander von Humboldt Postdoctoral Fellowship.  In June 2013, he moved to Curtin University (Perth, Australia) to start his own independent research group. In June 2015, he moved again to UNSW (Sydney) to take up a Lecturer/DECRA fellow position at the School of Chemistry. His current research interests are organocatalysis, aromatic cation activation, synthesis of naturally occurring and bioactive compounds, asymmetric synthesis and medicinal chemistry.

Selected Awards and Academic Achievements

• 2016: The 2016 Athel Beckwith Lectureship from RACI Organic Chemistry Division
• 2015-2018: ARC Discovery Early Career Researcher Award (DECRA)
• 2014: Thieme Chemistry Journal Award for outstanding early career academics.
• 2011 – 2013: Alexander von Humboldt Postdoctoral Fellowship (RWTH Aachen, Germany).
• 2005: The Era Polymer Prize for “The Best Honor Research Thesis” in Industrial Chemistry – UNSW
• 2000: Silver medal in the 32nd International Chemistry Olympiad in Copenhagen, Denmark

Research interests

Nguyen’s group focuses their research on development of new synthetic methodologies in organic chemistry, organocatalysis and natural product synthesis.

Aromatic Cation Activation:

A new method for the nucleophilic substitution of alcohols and carboxylic acids and other substrates using aromatic tropylium cation activation has been developed. It demonstrates, for the first time, the synthetic potential of tropylium cations in promoting chemical transformations. (http://pubs.acs.org/doi/abs/10.1021/ol5003972).

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Fe/ppm Cu nanoparticles as a recyclable catalyst for click reactions in water at room temperature

Fe/ppm Cu nanoparticles as a recyclable catalyst for click reactions in water at room temperature

Green Chem., 2017, 19,2506-2509
DOI: 10.1039/C7GC00883J, Communication

Aurelien Adenot, Evan B. Landstrom, Fabrice Gallou, Bruce H. Lipshutz
Nanomicelles housing a terminal alkyne and azide are delivered to ppm Cu-containing nanoparticles that catalyse click reactions in water at rt.

 

Fe/ppm Cu nanoparticles as a recyclable catalyst for click reactions in water at room temperature

Aurélien Adenot,a  Evan B. Landstrom,a  Fabrice Galloub  and  Bruce H. Lipshutz*a 

*Corresponding authors

aDepartment of Chemistry & Biochemistry, University of California, Santa Barbara, USA
E-mail: lipshutz@chem.ucsb.edu

bNovartis Pharma A6, Basel, Switzerland

Abstract

New iron-based nanoparticles doped with ppm levels of CuOAc are capable of catalyzing cycloadditions between alkynes and azides to afford triazole-containing products. These reactions take place in water at ambient temperatures, enabled by the presence of nanomicelles that function as a delivery mechanism. The NPs can be easily recycled within the same reaction vessel. Low levels of residual copper are found in the product.

(2) 1-Benzyl-4-phenyl-1H-1,2,3-triazole. Isolated as a white powdery crystal (99%).

Rf = 0.33 (1:3 EtOAc: hexanes).

NMR 1 H (CDCl3, 500 MHz, δ): 7.79-7.81 (m, 2H), 7.66 (s, 1H), 7.37-7.42 (m, 5H), 7.30-7.33 (m, 3H), 5.59 (s, 2H).

Melting point: 123-125 o C.

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The first continuous flow synthesis of C₈–C₁₆ alkane fuel precursors from biobased platform molecules is reported. TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene) was found to be a recyclable and highly efficient organic base catalyst for the aldol condensation of furfural with carbonyl compounds, and the selectivity of mono- or difuryl product can be easily regulated by adjusting the molar ratio of substrates. By means of flow technique, a shorter reaction time, satisfactory output, and continuous preparation are achieved under the present procedure, representing a significant advance over the corresponding batch reaction conditions.

Continuous Microflow Synthesis of Fuel Precursors from Platform Molecules Catalyzed by 1,5,7-Triazabicyclo[4.4.0]dec-5-ene

Tao Shen^†‡, Jingjing Tang^†‡, Chenglun Tang^†‡, Jinglan Wu^†‡, Linfeng Wang^∥, Chenjie Zhu^*†‡§ , and Hanjie Ying^†‡§

^† College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China

^‡National Engineering Technique Research Center for Biotechnology, Nanjing 211816, China

^§Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing 211816, China

^∥State Key Laboratory of Motor Vehicle Biofuel Technology, Nanyang 473000, China

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.7b00141

*E-mail: zhucj@njtech.edu.cn. Phone/Fax: +86 25 58139389.

http://pubs.acs.org/doi/abs/10.1021/acs.oprd.7b00141

 

1-(furan-2-yl)-2-methylpent-1-en-3-one

1a

3-pentanone (100 mmol, 8.6 g) and furfural (100 mmol, 9.6 g) were diluted with MeOH-H2O to 40 mL in stream 1, catalyst TBD (10 mmol, 1.39 g) were diluted with MeOH-H2O (v/v = 1/1) to 40 mL in stream 2, the two streams was purged in a 0.2 mL/min speed into slit plate mixer and at the 353 K passed tubing reactor. Finally, the product was extracted with EtOAc and water, the obtained organic layer was evaporated and purified by silica gel flash chromatography (25:1 hexane-EtOAc) to provide the analytically pure product for further characterization, the aqueous phase was collected and reused.According to the general procedure afforded 14.92 g (91%) of product 1a, isolated as pale yellow oil;

 

1H NMR (400 MHz, CD3OD) δ 7.62 (d, J = 1.4 Hz, 1H), 7.29 (s, 1H), 6.71 (d, J = 3.5 Hz, 1H), 6.52 (dd, J = 3.4, 1.8 Hz, 1H), 2.71 (q, J = 7.3 Hz, 2H), 2.05 (s, 3H), 1.04 (t, J = 7.3 Hz, 3H).

 

13C NMR (100 MHz, CD3OD) δ 203.5, 153.0, 145.8, 133.8, 126.8, 116.6, 113.3, 31.1, 13.2, 9.2.

 

  

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Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC00977A, Communication

Song Yao, Kaijing Zhou, Jiabing Wang, Hongen Cao, Lei Yu, Jianzhang Wu, Peihong Qiu, Qing Xu
An atom-efficient synthesis of 2-substituted quinazolines is developed by a CsOH-mediated aerobic oxidative reaction of 2-aminoarylmethanols and nitriles in air.

Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air

http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C7GC00977A?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

• From the journal:

  Green Chemistry

Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air

Song Yao,ab  Kaijing Zhou,b  Jiabing Wang,a  Hongen Cao,c  Lei Yu,c  Jianzhang Wu,*a  Peihong Qiu*a  and  Qing Xu*abc 

 Author affiliations

*Corresponding authors

aChemical Biology Research Center, College of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China
E-mail: wjzwzmu@163.com, wzqph@163.com
Tel: +86-158-25672558

bCollege of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, P. R. China
E-mail: qing-xu@wzu.edu.cn
Fax: +86-577-86689302
Tel: +86-138-57745327

cInstitute of Pesticide, School of Horticulture and Plant Protection and School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, China

Abstract

By using air as the superior oxidant, a highly atom-efficient synthesis of 2-substituted quinazolines is developed by a CsOH-mediated direct aerobic oxidative reaction of the readily available and stable 2-aminoarylmethanols and nitriles. Effectively working as the promoter in the alcohol oxidation, nitrile hydration, and cyclocondensation steps, CsOH is the best base for the reaction. A similar method can also be extended to the synthesis of substituted quinolines starting from methyl ketones instead of nitriles.

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