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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DR PRAVIN PATIL (Guest blogger) m-Chloroperbenzoic acid-oxchromium (VI)-mediated cleavage of 2,4,5-trisubstituted oxazoles

Here is the another publication details 

The paper is about m-CPBA/Chromium-VI mediated oxidation of oxazoles and published in Tetrahedron Letters recently.

m-Chloroperbenzoic acid-oxchromium (VI)-mediated cleavage of  2,4,5-trisubstituted oxazoles 

Pravin C. Patil and Frederick A. Luzzio*

Department of Chemistry, University of Louisville, 2320 South Brook Street, Louisville, Kentucky 40292 USA

[Invited article: Tetrahedron Letters 2017, 58 (13), 1280-1282]

http://www.sciencedirect.com/science/article/pii/S004040391730196X

DOI: https://doi.org/10.1016/j.tetlet.2017.02.027]

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Graphical Abstract:

Abstract:

An array of 2-substituted-4,5-diphenyloxazoles were found to be cleaved to triacylamines and diacylamines (imides) using a reagent system composed of 3-chloroperbenzoic acid (MCPBA) and 2,2'-bipyridinium chlorochromate (BPCC). The 2-alkyl-4,5-diphenyloxazoles give imides (38-60%) as the predominant cleavage product while the 2-aryl-4,5-diphenyloxazoles give triacylamines (62-71%). Two mechanisms involving intermediates such as cyclic endoperoxides or oxachromacycles were proposed. An application of the oxidative cleavage to the multi-step synthesis of phoracantholide I seco acid is detailed.

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Application of methodology toward synthesis of Phoracantholide-I seco acid

                                                                                          

 Highlights

A new method for the cleavage of 2,4,5-trisubstituted oxazoles to imides and triacylamines is detailed.

The oxidation system utilizes two reagents composed of a peroxide and oxochromium (VI).

Mechanisms are proposed for the oxidative cleavage reaction.

A synthesis of (±)-phoracantholide seco-acid is detailed.

ABOUT GUEST BLOGGER

Dr. Pravin C. Patil

Postdoctoral Research Associate at University of Louisville

Email, pravinchem@gmail.com

see…….http://oneorganichemistoneday.blogspot.in/2017/04/dr-pravin-patil.html

Dr. Pravin C Patil completed his B.Sc. (Chemistry) at ASC College Chopda (Jalgaon, Maharashtra, India) in 2001 and M.Sc. (Organic Chemistry) at SSVPS’S Science College Dhule in North Maharashtra University (Jalgaon, Maharashtra, India) in year 2003. After M.Sc. degree he was accepted for summer internship training program at Bhabha Atomic Research Center (BARC, Mumbai) in the laboratory of Prof. Subrata Chattopadhyay in Bio-organic Division. In 2003, Dr. Pravin joined to API Pharmaceutical bulk drug company, RPG Life Science (Navi Mumbai, Maharashtra, India) and worked there for two years. In 2005, he enrolled into Ph.D. (Chemistry) program at Institute of Chemical Technology (ICT), Matunga, Mumbai, aharashtra, under the supervision of Prof. K. G. Akamanchi in the department of Pharmaceutical Sciences and Technology.

After finishing Ph.D. in 2010, he joined to Pune (Maharashtra, India) based pharmaceutical industry, Lupin Research Park (LRP) in the department of process development. After spending two years at Lupin as a Research Scientist, he got an opportunity in June 2012 to pursue Postdoctoral studies at Hope College, Holland, MI, USA under the supervision of Prof. Moses Lee. During year 2012-13 he worked on total synthesis of achiral anticancer molecules Duocarmycin and its analogs. In 2014, he joined to Prof. Frederick Luzzio at the Department for Chemistry, University of Louisville, Louisville, KY, USA to pursue postdoctoral studies on NIH sponsored project “ Structure based design and synthesis of Peptidomimetics targeting P. gingivalis.

During his research experience, he has authored 23 international publications in peer reviewed journals and inventor for 4 patents.

//////////////guest blogger, pravin patil

Visible-light-induced and iron-catalyzed methylation of N-arylacrylamides with dimethyl sulphoxide: a convenient access to 3-ethyl-3-methyl oxindoles

Visible-light-induced and iron-catalyzed methylation of N-arylacrylamides with dimethyl sulphoxide: a convenient access to 3-ethyl-3-methyl oxindoles

Org. Biomol. Chem., 2017, Advance Article
DOI: 10.1039/C7OB00779E, Paper

Zuguang Xie, Pinhua Li, Yu Hu, Ning Xu, Lei Wang
An efficient synthesis of 3-ethyl-3-methyl oxindoles by visible-light promoted and iron-catalyzed difunctionalization of N-arylacrylamides with dimethyl sulphoxide was developed

Visible-light-induced and iron-catalyzed methylation of N-arylacrylamides with dimethyl sulphoxide: a convenient access to 3-ethyl-3-methyl oxindoles

Zuguang Xie,a  Pinhua Li,*a  Yu Hu,a  Ning Xua  and  Lei Wang*ab 

Author affiliations

*Corresponding authors

aDepartment of Chemistry, Huaibei Normal University, Huaibei, P. R. China
E-mail: pphuali@126.com, leiwang@chnu.edu.cn
Fax: +86-561-3090-518
Tel: +86-561-3802-069

bState Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, P. R. China

Abstract

A visible-light-induced and iron-catalyzed methylation of arylacrylamides by dimethyl sulphoxide (DMSO) is achieved, leading to 3-ethyl-3-methyl indolin-2-ones in high yields. This reaction tolerates a series of functional groups, such as methoxy, trifluoromethyl, cyano, nitro, acetyl and ethyloxy carbonyl groups. The visible-light promoted radical methylation and arylation of the alkenyl group are involved in this reaction.

 

 

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N-Methyl-3-Bromo-5-Methyl Pyrazole

N-Methyl-3-Bromo-5-Methyl Pyrazole

3·HCl as a white solid in 27% yield; sublimes at 40 °C; 1H NMR (500 MHz, DMSO-d6) δ 11.88 (s, 1 H), 6.07 (s, 1 H), 3.62 (s, 3 H), 2.16 (s, 3 H); 13C NMR (125 MHz, DMSO-d6) δ 141.7, 123.0, 107.5, 36.5, 10.9; HRMS-ESI (m/z) calcd for C5H8N2Br [M + H]+ 174.9864, found 174.9864.

3·TfOH as an off-white solid; mp = 145 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.73 (s, 1 H), 6.06 (s, 1 H), 3.62 (s, 3 H), 2.16 (s, 3 H); 13C NMR (100 MHz, DMSO-d6) δ 141.9, 123.2, 121.2 (q, J = 320 Hz), 107.6, 36.5, 10.9; HRMS-ESI (m/z) calcd for C5H8N2Br [M + H]+ 174.9864, found 174.9865.

Development of Scalable Processes for the Preparation of N-Methyl-3-Bromo-5-Methyl Pyrazole

Richard J. Fox* , Chester E. Markwalter, Michael Lawler, Keming Zhu, Jacob Albrecht, Joseph Payack, and Martin D. Eastgate

Chemical & Synthetic Development, Bristol-Myers Squibb Company, P.O. Box 191 New Brunswick, New Jersey 08903-0191, United States

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.7b00091

 

*E-mail: richard.fox@bms.com.

The development and optimization of two scalable routes to N-methyl-3-bromo-5-methyl pyrazole is described. The initial Sandmeyer route entailed a three-step sequence from crotonitrile and methyl hydrazine, proceeding through the 3-amino pyrazole intermediate. Due to the GTI liability of the 3-amino pyrazole intermediate, a tedious steam-distillation, and <30% overall yield, we developed a second-generation Sandmeyer-free approach from methyl crotonate and methyl hydrazine which leveraged a condensation, bromination, and oxidation sequence. Process development led to the improved preparation of N-methyl-3-bromo-5-methyl pyrazole with increased efficiency and overall yield. The isolation, handling, and storage of the final product was greatly improved through the generation of the triflic acid salt, and salt form studies are also discussed.

   

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.7b00091

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Asymmetric synthesis of ent-fragransin C1

http://pubs.rsc.org/en/Content/ArticleLanding/2017/OB/C7OB00749C?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FOB+%28RSC+-+Org.+Biomol.+Chem.+latest+articles%29#!divAbstract

Asymmetric synthesis of ent-fragransin C1

Org. Biomol. Chem., 2017, Advance Article
DOI: 10.1039/C7OB00749C, Paper

Santikorn Chaimanee, Manat Pohmakotr, Chutima Kuhakarn, Vichai Reutrakul, Darunee Soorukram
The first asymmetric synthesis of ent-fragransin C1 bearing 2,3-anti-3,4-syn-4,5-anti stereochemistries is reported.

Asymmetric synthesis of ent-fragransin C1

Santikorn Chaimanee,a  Manat Pohmakotr,a  Chutima Kuhakarn,a  Vichai Reutrakula  and  Darunee Soorukram*a 

*Corresponding authors

aDepartment of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand
E-mail: darunee.soo@mahidol.ac.th
Fax: +662 354 7151
Tel: +662201 5148

Abstract

The first asymmetric synthesis of ent-fragransin C1 was reported. The key step involves an intramolecular C–O bond formation (furan ring formation) via chemoselective generation of the benzylic carbocation leading to the 2,3-anti-3,4-syn-4,5-anti-tetrahydrofuran moiety as a single diastereomer in good yield. Our synthesis confirms that ent-fragransin C1 possesses 2R,3R,4S,5S configurations.

4-[(2R,3R,4S,5S)-5-(4-Hydroxy-3-methoxyphenyl)-3,4- dimethyltetrahydrofuran-2-yl]-2,6-dimethoxyphenol (ent-1). A flame-dried.......................... in vacuo, the crude product was purified by column chromatography (60% EtOAc in hexanes) to afford ent-1 as a sticky brownish oil (15.3 mg, 99% yield) as a single diastereomer (400 MHz 1 H NMR analysis). Rf 0.18 (40% EtOAc in hexanes);

[α]27 D -6.97 (c 0.60, CHCl3 ) (lit. [α]D +3.8 (c 0.60, CHCl3 ); 4a

UV (MeOH) λmax (log ε) 208 (0.85), 233 (0.24), 279 (0.07) nm; CD (MeOH) 226 (Δε 2.23), 250 (Δε +0.12).

1 H NMR (400 MHz, acetone-d6 ): δ 7.51 (s, 1H, OH), 7.12 (s, 1H, OH), 7.10 (d, J = 1.8 Hz, 1H, ArH), 6.92 (d, J = 8.1, 1.8 Hz, 1H, ArH), 6.82 (d, J = 8.1 Hz, 1H, ArH), 6.77 (s, 2H, 2  ArH), 4.43 (d, J = 5.4 Hz, 1H, 2  xCH), 3.86 (s, 3H, OCH3 ), 3.83 (s, 6H, 2  xOCH3 ), 2.202.45 (m, 2H, 2  xCH), 1.03 (d, J = 6.7 Hz, 3H, CH3 ), 1.00 (d, J = 6.7 Hz, 3H, CH3 ).

13C NMR (100 MHz, acetone-d6 ): δ 149.0 (2  C), 148.7 (C), 147.3 (C), 136.6 (C), 135.5 (C), 134.7 (C), 120.4 (CH), 115.9 (CH), 111.2 (CH), 105.1 (2  CH), 88.7 (CH), 88.4 (CH), 57.0 (2  CH3 ), 56.6 (CH3 ), 46.1 (CH), 45.7 (CH), 13.7 (CH3 ), 13.5 (CH3 ).

IR (CHCl3 ): νmax 3542s, 1616m, 1517s, 1465s, 1117s cm−1 .

MS (ISCID): m/z (%) relative intensity 397 [(M + Na)+ , 100], 357 (1).

HRMS (ESI-TOF) calcd for C21H26O6Na [M + Na]+ : 397.1627, found: 397.1622.

4 (a) M. Hattori, S. Hada, Y. Kawata, Y. Tezuka, T. Kikuchi and T. Namba, Chem. Pharm. Bull., 1987, 35, 3315; (

Darunee Soorukram

Assistant Professor

Darunee Soorukram

Education

• B.Sc. (Chemistry), Khon Kean University, Khon Kean, Thailand
• M.Sc. (Organic Chemistry), Mahidol University, Bangkok, Thailand
• Ph.D., Ludwig-Maximilians-University, Munich, Germany

Name : Darunee Soorukram     ดรุณี สู้รักรัมย์ Title : Assistant Professor Dr. Education : Ph.D. (Ludwig-Maximilians-University), Germany     Expertise : -     Contact Address : Department : Chemistry   Room : C418B   Phone : (662) 201 5148     E-Mail : darunee.soo@mahidol.ac.th         More Information : CV from Dept. Chemistry Website       รางวัลวิทยานิพนธ์ ระดับดีเยี่ยม (สาขาวิทยาศาสตร์เคมีและเภสัช) จากสภาวิจัยแห่งชาติ   Most Recent Articles from Scopus : Soorukram D (Author ID: 6506453550) O -Iodoxybenzoic Acid (IBX)-Iodine Mediated One-Pot Deacylative Sulfonylation of 1,3-Dicarbonyl Compounds: A Synthesis of β-Carbonyl Sulfones  2017; Synthesis (Germany); Katrun, P. | Songsichan, T. | Soorukram, D. | Pohmakotr, M. | Reutrakul, V. |... Cytotoxic lanostanes from fruits of Garcinia wallichii Choisy (Guttiferae)  2016; Bioorganic and Medicinal Chemistry Letters; Hongthong, S. | Meesin, J. | Pailee, P. | Soorukram, D. | Kongsaeree, P. |... Iodine-catalyzed Sulfonylation of Arylacetylenic Acids and Arylacetylenes with Sodium Sulfinates: Synthesis of Arylacetylenic Sulfones  (Cited 11 time(s)) 2016; Journal of Organic Chemistry; Meesin, J. | Katrun, P. | Pareseecharoen, C. | Pohmakotr, M. | Reutrakul, V. |... Decarboxylative sulfonylation of arylpropiolic acids with sulfinic acids: synthesis of (E)-vinyl sulfones  (Cited 1 time(s)) 2016; Tetrahedron; Meesin, J. | Katrun, P. | Reutrakul, V. | Pohmakotr, M. | Soorukram, D. |... Nitration-Oximization of Styrene Derivatives with tert-Butyl Nitrite: Synthesis of α-Nitrooximes  2016; Chinese Journal of Chemistry; Chumnanvej, N. | Katrun, P. | Pohmakotr, M. | Reutrakul, V. | Soorukram, D. |... Intramolecular Conjugate Ene Reaction of γ-Difluoromethyl- and γ-Trifluoromethyl-α,β-Unsaturated γ-Butyrolactones  2015; Journal of Organic Chemistry; Srimontree, W. | Masusai, C. | Soorukram, D. | Kuhakarn, C. | Reutrakul, V. |... Stereoselective Synthesis of 1-Fluoro-exo,exo-2,6-diaryl-3,7-dioxabicyclo[3.3.0]octanes: Synthesis of (±)-1-Fluoromembrine  (Cited 1 time(s)) 2015; Journal of Organic Chemistry; Punirun, T. | Soorukram, D. | Kuhakarn, C. | Reutrakul, V. | Pohmakotr, M. Synthesis of γ-difluoromethyl α,β-unsaturated γ-butyrolactones using PhSCF<inf>2</inf>SiMe<inf>3</inf> as a difluoromethylating agent  (Cited 3 time(s)) 2015; European Journal of Organic Chemistry; Issaree, A. | Masusai, C. | Soorukram, D. | Kuhakarn, C. | Reutrakul, V. |... Silver-mediated decarboxylative fluorination of paraconic acids: A direct entry to β-fluorinated γ-butyrolactones  (Cited 10 time(s)) 2015; European Journal of Organic Chemistry; Phae-Nok, S. | Soorukram, D. | Kuhakarn, C. | Reutrakul, V. | Pohmakotr, M. PhI(OAc)<inf>2</inf> mediated decarboxylative sulfonylation of β-aryl-α,β-unsaturated carboxylic acids: A synthesis of (E)-vinyl sulfones  (Cited 18 time(s)) 2015; Organic and Biomolecular Chemistry; Katrun, P. | Hlekhlai, S. | Meesin, J. | Pohmakotr, M. | Reutrakul, V. |... Access all results for your search in Scopus

Contact

Phone: +66.(0).2.201.5148

LAB Tel: +66.(0).2.201.5149
Fax: +66.(0).2.354.7151
E-mail:darunee.soo@mahidol.ac.th

Address:
Room C418B
Department of Chemistry,
Faculty of Science, Mahidol University,
Rama 6 Road, Ratchthewee
Bangkok 10400 Thailand

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Palladium-catalyzed coupling of azoles with 1-aryltriazenes via C–H/C–N cleavage

 

Palladium-catalyzed coupling of azoles with 1-aryltriazenes via C–H/C–N cleavage

Wei-Can Daia  and  Zhong-Xia Wang*ab 

*Corresponding authors

aCAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, P. R. China
E-mail: zxwang@ustc.edu.cn
Tel: +86 551 63603043

bCollaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, P. R. China

Abstract

In the presence of CuCl and ButOLi, PdCl2/dppe catalyzes the reaction of (benzo)oxazoles or (benzo)thiazoles with 1-aryltriazenes to yield arylated products of (benzo)oxazoles or (benzo)thiazoles. Functional groups including F, Cl, CF3, COOEt, CN, OMe, NMe2, Py, and thienyl groups can be tolerated.