Silver catalyzed three component reaction of phenyldiazoacetate with arylamine and imine

Chinese Journal of Catalysis 39 (2018) 1594 1598 催化学报 2018 年第 39 卷第 10 期 www.cjcatal.org available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/chnjc Communication Silver catalyzed three component reaction of phenyldiazoacetate with arylamine and imine Bai Ling Chen a,b, Zhen Wang a, You Can Zhang a, Zhi Gang Zhao b,#, Zili Chen a, * a Department of Chemistry, Renmin University of China, Beijing 100872, China b College of Chemistry & Environment Protection Engineering, Southwest University for Nationalities, Chengdu 610041, Sichuan, China A R T I C L E I N O Article history: Received 26 March 2018 Accepted 23 April 2018 Published 5 October 2018 Keywords: Silver catalysis Carbene transfer reaction Three component reaction Ammonium ylide Diamine compouds A B S T R A C T A new method was developed to diastereoselectively synthesize polysubstituted 1,2 diamine compounds from the reaction of diazoesters with arylamines and diaryl imines by using the dioxazoline ligand L2 ligated silver catalyst. The Lewis acidity of the silver catalyst affected the different types of substrate diastereoselectivities; It also led to the formation of amine exchange side products. 2018, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved. The metal catalyzed carbene transfer reaction of diazo compounds has become an important synthetic tool in organic synthesis [1,2]. In this field, the reactions of cyclopropanation, X (X = C, N, O, Si, S) insertion, and carbonyl/imine ylide cycloaddition have been extensively investigated in the past decades. In 2003, u and his colleagues described a new type of reaction, in which the seemingly unstable ammonium ylides could be trapped with imine, giving 1,2 diamines with a high diastereoselectivity (Eq. (3), Scheme 1) [3 7]. In their subsequent research, ammonium ylides and oxonium ylides intermediates [8,9] were found to undergo nucleophilic addition onto a series of suitable electrophiles, such as ketone [10], aldehyde [11,12], β, γ unsaturated α ketoester [13,14], and azodicarboxylate [15]. These diazo compound reactions were usually mediated through rhodium (III) catalysis [16 19]. Our group have recently reported that silver salts could be utilized as a catalyst to mediate the carbene transfer reaction of diazo compounds for the synthesis of oxirane molecules through the [2+1] cycloaddition of the diazo compounds with aldehydes (Eq. (1), Scheme 1) [20], and of 2,5 dihydrofurans/tetrahydrofurans through the [2+2+1] cycloaddition of the diazo compounds with aldehydes and alkyne/olefin dipolarophiles (Eq. (2), Scheme 1) [21]. As a continuation of our previous research, we herein explore the silver (I) catalyzed three component reactions of phenyl diazoacetate with arylamine and imine, which provide a series of polysubstituted 1,2 diamine derivatives in moderate to good yields [22 25]. The reaction of methyl phenyldiazoacetate 1a with phenylamine 2a and 4 nitrophenyl N phenylmethanimine 3a was chosen as the model system for our initial investigation. ollowing our previous procedure, the combination IPrAgCl/AgOTf was utilized as the catalyst. As shown in Table 1, a mixture of 1a (0.1 mmol), 1.2 mol equiv. of 2a and 6 mol * Corresponding author. Tel/ax: +86 10 62516660; E mail: zilichen@ruc.edu.cn # Corresponding author. E mail: zzg63129@163.com This work was supported by the National Natural Science oundation of China (21472237). DOI: 10.1016/S1872 2067(18)63088 8 http://www.sciencedirect.com/science/journal/18722067 Chin. J. Catal., Vol. 39, No. 10, October 2018

Bai Ling Chen et al. / Chinese Journal of Catalysis 39 (2018) 1594 1598 1595 ig. 1. The X Ray structure of compound 4aa. Scheme 1. Ag(I) and Rh(III) mediated carbene transfer reaction. Table 1 Silver mediated ammonium ylide trapping reaction with 4 nitrophenyl N phenylmethanimine 3a. a Entry Ag catalyst Additive Solvent/ Yield of (mol%) (mol%) 4Å MS(mg) 4aa/5a b (%) 1 IPrAgCl (5) AgOTf (5) DCM/50 33/26 2 AgOTf (5) None DCM/50 18/31 3 IPrAgCl (5) AgOTf (5) CCl3/50 22/25 4 IPrAgCl (5) AgOTf (5) DCE/50 20/23 5 IPrAgCl (5) AgOTf (5) Toluene/50 11/23 6 IPrAgCl (5) AgOTf (5) Dioxane/50 5/16 7 IPrAgCl (5) AgOTf (5) DCM/10 60/21 8 IPrAgCl (5) AgOTf (5) DCM/0 42/15 9 AgOTf (5) PPh3 (5) DCM/10 19/27 10 AgOTf (5) L1 (5) DCM/10 41/18 11 AgOTf (5) L2 (5) DCM/10 91/5 12 AgOTf (5) L3 (5) DCM/10 <5/14 13 AgNTf2 (5) L2 (5) DCM/10 88/11 14 AgSb6 (5) L2 (5) DCM/10 51/17 15 AgP6 (5) L2 (5) DCM/10 17/25 16 AgB4 (5) L2 (5) DCM/10 45/14 17 AgClO4 (5) L2 (5) DCM/10 69/12 18 Ag2O (5) L2 (5) DCM/10 NR 19 Ag2CO3 (5) L2 (5) DCM/10 NR 20 c AgOTf (5) L2 (5) DCM/10 47/15 21 d AgOTf (5) L2 (5) DCM/10 65/13 a Unless noted, all reactions were carried out on 0.1 mmol scale in 2 ml solvent at room temperature. b The reaction yields were determined by 1 NMR spectral data. c The reaction was performed at 0 C. d The reaction was performed at 40 C. In Table 1 scheme, 4aa, 5a, L2 and L3 structures only show relative configurations. equiv. of 3a in C2Cl2 was treated with 5 mol% equiv. of IPrAgCl/AgOTf using 50 mg 4 Å molecular sieves. We found that the diamine product 4aa could be obtained in 33% yield, together with the N insertion product 5a (26% yield, Table 1, entry 1). The diastereoselectivity of 4aa was very high (dr = 20/1). The relative stereochemistry of 4aa was found to be a (2S*, 3S*) configuration, as determined by its X ray chromatograph, shown in ig. 1 [26]. urther optimization of the reaction conditions was then performed. It was found that the removal of IPrAgCl (no IPr ligand condition) would reduce the yield of 4a (Table 1, entry 2). After solvent screening (Table 1, entries 3 6), DCM was found to be the best reaction medium. The effect of molecular sieves was tested, 10 mg of the 4 Å molecular sieve additive was the optimal amount (Table 1, entry 7and 8). Except for IPr, other ligands were explored. Both PPh3 and the dioxazoline ligand L1 proved to be inferior to IPr (Table 1, entries 9 and 10). Luckily, L2 ligated silver salts afforded the desired product 4aa in a high yield (Table 1, entry 11). owever, the tricoordinated L3 proved to be a poor ligand (Table 1, entry 12). Utilizing L2 as the ligand, various silver salts were scrutinized, in which the AgOTf activity is much better than those of the other silver salts (Table 1, entries 13 19). In addition, raising or lowering the reaction temperature was found to be ineffective (Table 1, entries 20 and 21). With the optimized reaction conditions determined, the various substrate scopes were then explored. As shown in Ta Table 2 Ammonium ylide trapping reaction of various diazo esters via silver catalysis a, b, c. N 2 + 2a + Ar COOMe 4ba, 83% yield dr = 25/1 1 4fa, 70% yield dr = 29/1 3a Ag(I), L2, 4ca, 95% yield dr = 24/1 4ga, 55% yield dr = 19/1 Ar 4 R NPh 4da, R=EtO, 84% yield, dr = 27/1 4ea, R=MeO, 85% yield, dr = 22/1 S 4ha, 37% yield dr =10/1 Unless noted, all reactions were carried out on 0.1 mmol scale in 2 ml solvent at room temperature with the addition of 10 mg 4 Å molecular sieves. b Isolated yields. c The dr values were determined by 1 NMR spectral data of the crude product. In Table 2, the 4ba 4ha structures only show their relative configurations.

1596 Bai Ling Chen et al. / Chinese Journal of Catalysis 39 (2018) 1594 1598 ble 2, a series of diazo esters were investigated by using phenylamine 2a and 4 nitrophenyl N phenylmethanimine 3a as the ammonium ylide trapping partner. The ethyl phenyldiazoacetate ester 1b behaved like methyl ester 1a, giving 4ba in 83% yield with dr = 25/1 (Table 2). Different phenyl substitution patterns were tested, in which the electro rich substituents (Table 2, 4ca 4ea) performed better than the electro poor analogs (Table 2, 4fa). The bulky 2 naphthalenyl diazoester and heteroaromatic 2 thiophenyl diazo ester were also investigated, providing the desired diamine products 4ga and 4ha in moderate yields with high diastereoselectivities (Table 2) [27]. Then, various amine and imine substrates were investigated. It was found that an amine exchange could occur between the amine and imine substrates. In order to avoid the formation of an amine exchanging side product, the same amine subunit (Ar1N2) was employed in the amine substrate 2 and imine substrate 3 (Table 3). It has been proposed that the imine substrates act as ammonium ylide trapping reagents. Thus, its electrophilicity might affect the result of this three component coupling reaction. As shown in Table 3, when the highly electrophilic imines, derived from p nitro benzaldehyde, were utilized, the reactions of 1a with different amine substrates, such as p fluoro, p chloro and p trifluoromethyl amines, provided diamine products 4ab 4ad in moderate yields with high diastereoselectivities, which were higher than that of Rh(III) catalysis (Table 3) [3]. owever, when the less electrophilic p trifluoromethyl phenyl substituted imine 3e was utilized, two diamine diastereomers 4ae and 4ae could be obtained in 43% yield, with dr = 1.5/1 (Table 3) [28]. Similarly, the reaction of the unsubstituted diphenyl imine 3f afforded the two diastereomers 4af and 4af with a relatively low diastereoselectivity (4af/4af = 3/1, Table 3). In the reaction of the p methyl diphenyl imine 3g, the corresponding diamine diastereomers 4ag and 4ag were Table 3 Silver mediated ammonium ylide trapping reaction by using the same Ar1 unit in the amine and imine substrates a, b, c. 1a N N N Ar 1 + Ar 1 N 2 + Ar 2 2 3 4ab, 69% yield dr =27/1 N Cl N 4ac, 73% yield dr =25/1 Ag(I), L2, Ar 1 N hp 4 Ar 2 NAr 1 N 3 C N Cl 4ad,68%yield dr =19/1 C 3 separated in 31% yield, with dr = 2/1 (Table 3). Then, the amine exchange process was explored in the silver mediated ammonium ylide trapping reaction. As shown in Scheme 2, when the p fluorophenyl amine 2b was utilized to react with the diazo ester 1a and imine 3a, two ammonium ylide trapping adducts 4ah and 4aa were synthesized, in which the normal coupling adduct 4ah was obtained in only 23% yield (Scheme 2, Eq. (3)). It was obvious that an amine exchange reaction occurred between 2b and 3a, which led to the formation of the amine exchange coupling product 4aa [29]. Similarly, in the reaction of the p trifluoromethylphenyl amine 2d, both 4am and amine exchange product 4aa could be separated from the Ag(I)/L2 mediated reaction (Scheme 2, Eq. (4)). As a comparison, the Rh(III) catalyst was used to catalyze the reactions in Eqs. (3) and (4), in which an amine exchange product 4aa could also be obtained, though with relatively low yields (Scheme 2). Then, we explored the asymmetric three component reaction by using the chiral ligand (R) L2, however, no enantioselectivity was obtained in the reaction shown in Eq. (5) (Scheme 3). In the N insertion reaction, only 11% ee was obtained (Eq. (6), Scheme 3). The mechanism of the Ag(I) catalyzed ammonium ylides trapping reaction was then discussed. Based on previous research, a process of the nucleophilic addition of ammonium ylides onto electrophilic imines would be involved, in which the product diastereoselectivities are determined by intermolecular hydrogen bonding between the ArN2 group and the imine nitrogen atom, and the π π interactions of the phenyl group[3]. Because of the Lewis acidity of the Ag(I) salt, we considered that an additional intermolecular silver coordination might be 1a + N 2 + 3a 2b 1a + 3 C N 2 + 3a 2d Ag(I), L 2, Ag(I), L 2 Rh(OAc) 2,reflux N 3 C 4ai Ag(I), L 2 Rh(OAc) 2,reflux N 4ah 23 % yield 42 % yield 28% yield 36% yield NPh NPh + 4aa 41 % yield 12 % yield + 4aa 28% yield 18% yield NPh NPh Scheme 2. Amine exchange process involved in the Ag(I)/Rh(III) mediated ammonium ylide trappingreaction. (3) (4) C 3 N N Ag(I): (4ae+4ae'), 43% yield, dr =1.5/1 N N Ag(I): (4af+4af'), 51% yield, dr =3/1 N N Ag(I): (4ag+4ag'), 31% yield, dr =2/1 a Unless noted, all reactions were carried out on 0.1 mmol scale in 2 ml C2Cl2 at room temperature with the addition of 10 mg 4 Å molecular sieves. b Isolated yields. c The dr values were determined from the 1 NMR spectral data of the crude product. The product 4ab 4ag structures only show their relative configurations. Scheme 3. Exploring the asymmetric three component reaction and the N insertion reaction.

Bai Ling Chen et al. / Chinese Journal of Catalysis 39 (2018) 1594 1598 1597 L 2 Ag L O OMe O O OMe 2 Ag Ph N O N Ar N Ph N Ph Ar N Ph R R=,C 3,,C 3 avored Unfavored Scheme 4. Plausible transition state for ammonium ylide trapping reaction. involved, which led to the high diastereoselectivity of p nitrophenyl imine in the Ag(I) mediated reaction (favored transition state, Scheme 4). When other imine substrates, such as p trifluoromethylphenyl, p methylphenyl and unsubstituted phenyl imines, were tested, poor diastereoselectivities were observed, possibly because of the coordination of silver salts with the imine nitrogen atom (unfavored transition state, Scheme 4). In addition, the amine exchange process between the amine and imine substrates might also be a result of the Lewis acidity of the Ag(I) salt, leading to the amine exchange three component reaction. In summary, we have reported the first example of the Ag(I) catalyzed three component reaction of a diazo ester with arylamine and diaryl imine by using dioxazoline L2 as the ligand to synthesize a series of polysubstituted 1,2 diamine compounds in moderate to good yields. The Lewis acidity of Ag(I) affected the diastereoselectivities of the 1,2 diamine molecule, and led to the formation of amine exchange diamine adducts. Compared with the previously reported Rh(III) mediated reaction, the silver catalyst performed better for the reactions of the p nitrophenyl imine substrates, while providing relatively lower enantioselectivities for the reactions of less electrophilic substrates. Moreover, it was found that the dioxazoline L2 ligand greatly enhanced the Ag(I) catalytic activities in the carbene transfer reaction. The detailed research of the silver catalyzed ammonium ylide trapping reaction and its further application is ongoing in our laboratory and will be reported in due course. Supplementary data Supplementary data associated with this article include: a brief experimental details, and spectral data for all new products and NOESY spectra for compound 4aa is available free of charge via the Internet. References [1] M. P. Doyle, M. A. McKervey, T. Ye, Modem Catalytic Methods for Organic Synthesis with Diazo Compounds, John Wiley and Sons, New York, 1998, 652. [2] A. Padwa, S.. ornbuckle, Chem. Rev., 1991, 91, 263 309. [3] Y.. Wang, Y. X. Zhu, Z. Y. Chen, A. Q. Mi, W.. u, M. P. Doyle, Org. Lett., 2003, 5, 3923 3926. [4] J. Jiang, X. Ma, C. Ji, Z. Guo, T. Shi, S. Liu, W. u, Chem. Eur. J., 2014, 20, 1505 1509. [5] J. Jiang,. D. Xu, J. B. Xi, B. Y. Ren,. P. Lv, X. Guo, L. Q. Jiang, Z. Y. Zhang, W.. u, J. Am. Chem. Soc., 2011, 133, 8428 8431. [6] R. R. Lei, Y. Wu, S. Z. Dong, K. L. Jia, S. Y. Liu, W.. u, J. Org. Chem. 2017, 82, 2862 2869. [7] L. Q. Jiang, D. Zhang, Z. Q. Wang, W.. u, Synthesis, 2013, 45, 452 458. [8] T. D. Shi, X. Guo, S.. Teng, W.. u, Chem. Commun., 2015, 51, 15204 15207. [9] L. Qiu, X. Guo, C. C. Jing, C. Q. Ma, S. Y. Liu, W.. u, Chem. Com Graphical Abstract Chin. J. Catal., 2018, 39: 1594 1598 doi: 10.1016/S1872 2067(18)63088 8 Silver catalyzed three component reaction of phenyldiazoacetate with arylamine and imine Bai Ling Chen, Zhen Wang, You Can Zhang, Zhi Gang Zhao *, Zili Chen * Renmin University of China; Southwest University for Nationalities Polysubstituted 1,2 diamines were obtained from the reaction of diazoesters with arylamines and diaryl imines by using the dioxazoline Ag(I) catalyst. The Lewis acidity of silver affected the substrate diastereoselectivities and led to the formation of amine exchange side products.

1598 Bai Ling Chen et al. / Chinese Journal of Catalysis 39 (2018) 1594 1598 mun., 2016, 52, 11831 11833. [10] C. C. Jing, D. Xing, W.. u, Chem. Commun., 2014, 50, 951 953. [11] Y.. Wang, Z. Y. Chen, A. Q. Mi, W.. u, Chem. Commun., 2004, 2486 2487. [12] J. B. Xi, M. L. Ma, W.. u, Tetrahedron, 2016, 72, 579 583. [13] Y. G. Zhu, C. W. Zhai, Y. L. Yue, L. P. Yang, W.. u, Chem. Commun., 2009, 1362 1364. [14] S. K. Jia, Y. B. Lei, L. L. Song, S. Y. Liu, W.. u, Chin. Chem. Lett., 2017, 28, 213 217. [15]. X. uang, Y.. Wang, Z. Y. Chen, W.. u, Adv. Synth. Catal., 2005, 347, 531 534. [16] D.. Chen,. Zhao, Y. u, L. Z. Gong, Angew. Chem. Int. Ed., 2014, 53, 10763 10767. [17]. Qiu, M. Li, L. Q. Jiang,. P. Lv, L. Zan, C. W. Zhai, M. P. Doyle, W.. u, Nat. Chem., 2012, 4, 733 738. [18] D. Zhang, J. Zhou,. Xia, Z.. Kang, W.. u, Nat. Commun., 2014, 6, 5801 5808. [19] S. K. Jia, D. Xing, D. Zhang, W.. u, Angew. Chem. Int. Ed., 2014, 53, 13098 13101. [20] Z. Wang, J. Wen, Q. W. Bi, X. Q. Xu, Z. Q. Shen, X. X. Li, Z. L. Chen, Tetrahedron Lett., 2014, 55, 2969 2972. [21] Y.. Liu, Z. Wang, J. W. Shi, B. L, Chen, Z. G. Zhao, Z. Chen, J. Org. Chem., 2015, 80, 12733 12739. [22] K. Burgess,. J. Lim, A. M. Porte, G. A. Sulikowski, Angew. Chem. Int. Ed., 1996, 35, 220 222. [23]. V. R. Dias, R. G. Browning, S. A. Polach,. V. K. Diyabalanage, C. J. Lovely, J. Am. Chem. Soc., 2003, 125, 9270 9271. [24] J. L. Thompson,. M. L. Davies, J. Am. Chem. Soc., 2007, 129, 6090 6091. [25] Y. J. Su, M. Lu, B. L. Dong,. Chen, X. D. Shi, Adv. Synth. Catal., 2014, 356, 692 696. [26] The relative stereochemistry of 4aa is same as the result of Rh(III) catalyzed reaction. The minor product 4aa has also been isolated (from the 5 mmol scale reaction) and characterized by using 1 NMR & 13 C NMR spectroscopy and RMS. [27] It was notable 4ba 4ha s diasteroselectivities are higher than the results of Rh(III) catalyzed reaction reported in previous research. [28] Compound 4ae is inseparable from the N insertion product. [29] Another type of possible amine exchange side product, with phenylamine acting as the nucleophile, and N (4 fluorophenyl) 1 (4 nitrophenyl)methanimine (the amine exchange imine substrate) as the electrophile, was not observed in Eq (3) s reaction. Eq (4) s result is similar to Eq (3). 银催化重氮酯与苯胺, 亚胺的三组分反应 陈佰灵 a,b, 王振 a, 张有灿 a, 赵志刚 b,# a,*, 陈自立 a 中国人民大学化学系, 北京 100872 b 西南民族大学化学与环境保护工程学院, 四川成都 610041 摘要 : 过渡金属催化重氮化合物的卡宾转移反应是有机合成反应的重要研究对象. 在这一类反应中, 包括环丙烷化 X- (X = C, N, O, Si, S) 插入以及羰基 / 亚胺叶立德环加成等反应得到了广泛的研究. 2003 年, 胡文浩和 Doyle 课题组报道了一种新型的反应, 即亚胺捕获看似不稳定的氨基叶立德中间体, 合成具有高非对映选择性的 1,2- 二胺化合物. 之后, 他们又报道了一系列有关氨基叶立德和氧叶立德的研究, 与不同的捕获剂, 如酮, 醛, β, γ- 不饱和 α 羰基羧酸酯和偶氮二酸酸酯等发生反应, 生成多种多样的产物类型, 基本上都是采用 Rh(III) 催化剂. 迄今为止, 没有采用其他类型的过渡金属催化剂的报道. 最近, 本课题组研究发现, 银盐可以作为重氮化合物卡宾转移反应的催化剂, 实现了重氮化合物与醛的 [2+1] 环加成反应合成环氧乙烷类化合物, 及重氮化合物与醛 炔 / 烯三组分的 [2+2+1] 环加成反应合成二氢呋喃 / 四氢呋喃类化合物, 在这些反应中, 加入不同的配体可以调节 Ag(I) 催化剂的催化活性, 从而实现不同的反应过程. 基于此, 本文将探索 Ag(I) 做催化剂催化重氮化合物与芳基胺及亚胺的三组分反应合成一系列 1,2- 二胺类化合物. 研究发现, 采用 AgOTf/ 双噁唑啉配体配体作为催化剂组合, 可以顺利地实现 Ag(I) 催化重氮酯 芳基胺及亚胺的三组分反应. 尝试了不同的配体, 包括膦配体 卡宾配体以及双噁唑啉配体, 最后发现, 双噁唑啉配体配位的 Ag(I) 催化反应的效果最好, 极大地提高了 Ag(I) 催化剂的催化活性, 其具体的作用机理值得进一步研究. 反应中, Ag(I) 催化剂的 Lewis 酸性对二胺产物的非对映选择性有较大的影响. 其中, 在对硝基苯基亚胺的反应中, 产物的非对映选择性很高, 大于铑催化反应的结果 ; 而在其他类型亚胺的反应中, 反应的非对映选择性较差. 另一方面, 由于 Ag(I) 的 Lewis 酸性, 反应过程中发生亚胺与芳基胺的氨基交换反应, 从而导致氨基交换的二胺副产物的生成. 本文对不同反应底物的各种效应进行了比较详细的研究. 关键词 : 银催化 ; 卡宾转移反应 ; 三组分反应 ; 铵基叶立德 ; 二胺化合物 收稿日期 : 2018-03-26. 接受日期 : 2018-04-23. 出版日期 : 2018-10-05. * 通讯联系人. 电话 / 传真 : (010)62516660; 电子信箱 : zilichen@ruc.edu.cn # 通讯联系人. 电子信箱 : zzg63129@163.com 基金来源 : 国家自然科学基金 (21472237). 本文的电子版全文由 Elsevier 出版社在 ScienceDirect 上出版 (http://www.sciencedirect.com/science/journal/18722067).