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Copper-Catalyzed N-Cyanation of Sulfoximines by AIBN Fan Teng, Jin-Tao Yu, Zhou Zhou, Haoke Chu, and Jiang Cheng J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/jo502607c • Publication Date (Web): 10 Feb 2015 Downloaded from http://pubs.acs.org on February 18, 2015
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
The Journal of Organic Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
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The Journal of Organic Chemistry
Copper-Catalyzed N-Cyanation of Sulfoximines by AIBN Fan Teng,a Jin-Tao Yu,a Zhou Zhou,a Haoke Chu,a and Jiang Cheng*,a,b
a
School of Petrochemical Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou, 213164, P. R. China. b College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, P. R. China.
[email protected]
RECEIVED DATE (to be automatically inserted after your manuscript is accepted if required according to the journal that you are submitting your paper to)
ABSTRACT
The direct copper-catalyzed N-cyanation of sulfoximines was achieved by using AIBN as a safe cyanide source. It represents a simple and environmentally benign procedure for the construction of N-CN bond. Furthermore, some secamines can also be tolerated well under this procedure.
The N-CN bonds are ubiquitous and frequently found in innumerable natural products, biologically active molecules and medicinally relevant structures (Scheme 1).1-5 For example, sulfoxaflor and thiacloprid play key roles in insecticide field.6-7 Inhibitors of cathepsin K show efficiency on bone resorption,1 while inhibitors of cathepsin C are utilized in neutrophil-dominated inflammatory diseases.5 Meanwhile, cyanamides are not only employed as ligands in coordination chemistry,8-11 but also the key intermediates leading to guanidines12-16 and heterocycles.17-24 Moreover, as a safe cyanide source, cyanamides were widely applied in the cyanation reaction.25-28
Scheme 1 Bioactive Compounds Containing N-CN Bonds.
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The Journal of Organic Chemistry
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To date, several elegant approaches have been developed in C-CN bond formation by safe cyanide sources.29-42 However, to the best of our knowledge, the construction of N-CN bond was generally limited to von Braun reaction, where XCN (X= halo) was highly toxic.43-45 Very recently, we developed the formation of N-CN bond via oxidative coupling using CuCN as cyanide source.46 In view of the toxicity of CuCN, the development of safe cyanide source in N-CN bond formation is still highly promising. Scheme 2 The Employment of AIBN as “CN” Source
AIBN was widely known as a radical initiator.47-48 However, recently, Han pioneered the application of AIBN as “CN” source in the formation of C-CN bonds (Scheme 2, eq 1).49 Subsequently, we described an S-cyanation reaction by AIBN (Scheme 2, eq 2).50 Herein, we wish to report the employment of AIBN in N-cyanation of sulfoximines (Scheme 2, eq 3). Importantly, N-cyano sulfoximines have attracted significant attention in crop protection as promising pesticides.6-7, 51 Table 1. Optimization of the Reaction Conditions a
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The Journal of Organic Chemistry
entry
catalyst
solvent
base
yield (%)
1 2 3 4 5 6 7 8 9 10 11 12
CuBr2 Cu(OAc)2 CuS CuI -CuI CuI CuI CuI CuI CuI CuI
MeCN MeCN MeCN MeCN MeCN DCM 1,4-dioxane MeOH MeCN MeCN MeCN MeCN
K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 -NaHCO3 K3PO4 TEA
65 38 18 90 (20%)b(< 1)c
Note
Copper-Catalyzed N-Cyanation of Sulfoximines by AIBN Fan Teng, Jin-Tao Yu, Zhou Zhou, Haoke Chu, and Jiang Cheng J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/jo502607c • Publication Date (Web): 10 Feb 2015 Downloaded from http://pubs.acs.org on February 18, 2015
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
The Journal of Organic Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 14
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
The Journal of Organic Chemistry
Copper-Catalyzed N-Cyanation of Sulfoximines by AIBN Fan Teng,a Jin-Tao Yu,a Zhou Zhou,a Haoke Chu,a and Jiang Cheng*,a,b
a
School of Petrochemical Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou, 213164, P. R. China. b College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, P. R. China.
[email protected]
RECEIVED DATE (to be automatically inserted after your manuscript is accepted if required according to the journal that you are submitting your paper to)
ABSTRACT
The direct copper-catalyzed N-cyanation of sulfoximines was achieved by using AIBN as a safe cyanide source. It represents a simple and environmentally benign procedure for the construction of N-CN bond. Furthermore, some secamines can also be tolerated well under this procedure.
The N-CN bonds are ubiquitous and frequently found in innumerable natural products, biologically active molecules and medicinally relevant structures (Scheme 1).1-5 For example, sulfoxaflor and thiacloprid play key roles in insecticide field.6-7 Inhibitors of cathepsin K show efficiency on bone resorption,1 while inhibitors of cathepsin C are utilized in neutrophil-dominated inflammatory diseases.5 Meanwhile, cyanamides are not only employed as ligands in coordination chemistry,8-11 but also the key intermediates leading to guanidines12-16 and heterocycles.17-24 Moreover, as a safe cyanide source, cyanamides were widely applied in the cyanation reaction.25-28
Scheme 1 Bioactive Compounds Containing N-CN Bonds.
ACS Paragon Plus Environment
The Journal of Organic Chemistry
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
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To date, several elegant approaches have been developed in C-CN bond formation by safe cyanide sources.29-42 However, to the best of our knowledge, the construction of N-CN bond was generally limited to von Braun reaction, where XCN (X= halo) was highly toxic.43-45 Very recently, we developed the formation of N-CN bond via oxidative coupling using CuCN as cyanide source.46 In view of the toxicity of CuCN, the development of safe cyanide source in N-CN bond formation is still highly promising. Scheme 2 The Employment of AIBN as “CN” Source
AIBN was widely known as a radical initiator.47-48 However, recently, Han pioneered the application of AIBN as “CN” source in the formation of C-CN bonds (Scheme 2, eq 1).49 Subsequently, we described an S-cyanation reaction by AIBN (Scheme 2, eq 2).50 Herein, we wish to report the employment of AIBN in N-cyanation of sulfoximines (Scheme 2, eq 3). Importantly, N-cyano sulfoximines have attracted significant attention in crop protection as promising pesticides.6-7, 51 Table 1. Optimization of the Reaction Conditions a
ACS Paragon Plus Environment
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
The Journal of Organic Chemistry
entry
catalyst
solvent
base
yield (%)
1 2 3 4 5 6 7 8 9 10 11 12
CuBr2 Cu(OAc)2 CuS CuI -CuI CuI CuI CuI CuI CuI CuI
MeCN MeCN MeCN MeCN MeCN DCM 1,4-dioxane MeOH MeCN MeCN MeCN MeCN
K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 -NaHCO3 K3PO4 TEA
65 38 18 90 (20%)b(< 1)c
