在L-脯氨酸催化的芳香醛与丙酮直接不对称aldol反应体系中添加二醇或二酚类助剂可有效提高反应活性.助剂的使用降低了该反应体系中L-脯氨酸的用量.特别是以邻苯二酚为助剂时,最佳反应条件下,仅用5mol％L-脯氨酸与1mol％助剂催化2-硝基苯甲醛与丙酮直接不对称aldol反应,aldol产物产率高达90％,对映选择性为80％.该反应产率比未加助剂条件下,L-脯氨酸用量为30mol％时的反应产率高.采用量子化学计算研究了助剂对该反应的促进作用.结果表明,助剂可与芳香醛的醛基形成氢键,从而活化醛基,提高反应效率.邻苯二酚结构中相邻的羟基能与底物芳香醛羰基的氧原子形成双氢键,大大活化了底物芳香醛的羰基.因此,该助剂可有效促进L-脯氨酸催化剂的直接不对称aldol反应.
The direct asymmetric aldol reaction of aromatic aldehydes with acetone catalyzed by L-proline was accelerated by the addition of diois or diphenols.The use of additives decrease the amount of L-proline needed and allowed the use of solvent free conditions.Catechol with two adjacent hydroxy groups on aromatic ring was the most efficient additive.Under the optimized conditions,5 mol％ L-proline with 1mol％ catechol gave excellent chiral selectivity (80％ ee value) with ＞ 90％ yield,which was higher than that obtained using 30 mol％L-proline without an additive.Computations indicated that the additive promoted the reaction by an intermolecular hydrogen bond between the hydrogen of the hydroxyl group and the oxygen of the carbonyl group,which activated the carbonyl group of the aldehyde.Catechol with two adjacent hydroxyl groups on the aromatic ring can form two hydrogen bonds with the oxygen of the carbonyl group on the corresponding aldehyde.Therefore,the combination of L-proline and catechol was very efficient in catalyzing the direct asymmetric aldol reaction and gave a high yield in a short time.
参考文献
| [1] | Trost BM.;Ito H. .A direct catalytic enantioselective aldol reaction via a novel catalyst design[J].Journal of the American Chemical Society,2000(48):12003-12004. |
| [2] | Yamada Y M A;Yoshikawa N;Sasai H;Shibasaki M .[J].Angewandte Chemie International Edition,1997,36:1871. |
| [3] | List B.;Barbas CF.;Lerner RA. .Proline-catalyzed direct asymmetric aldol reactions[J].Journal of the American Chemical Society,2000(10):2395-2396. |
| [4] | Notz W;List B .[J].Journal of the American Chemical Society,2000,122:7386. |
| [5] | Schmid M B;Zeitler K;Gschwind R M .[J].Angewandte Chemie International Edition,2010,49:4997. |
| [6] | Zhu X;Tanaka F;Lerner R A;Barbas Ⅲ C F Wilson I A .[J].Journal of the American Chemical Society,2009,131:18206. |
| [7] | Chimni SS;Mahajan D .Electron deficiency of aldehydes controls the pyrrolidine catalyzed direct cross-aldol reaction of aromatic/heterocyclic aldehydes and ketones in water[J].Tetrahedron,2005(21):5019-5025. |
| [8] | Hayashi Y;Sumiya T;Takahashi J;Gotoh H,Urushima T,Shoji M .[J].Angewandte Chemie International Edition,2006,45:958. |
| [9] | Loh T P;Feng L C;Yang H Y;Yang J Y .[J].Tetrahedron Letters,2002,43:8741. |
| [10] | Mukherjee S;Yang J W;Hoffmann S;List B .[J].Chemical Reviews,2007,107:5471. |
| [11] | Wang B;Chen G H;Liu L Y;Chang W X Li J .[J].Advanced Synthesis and Catalysis,2009,351:2441. |
| [12] | Hayashi Y;Aratake S;Okano T;Takahashi J,Sumiya T,Shoji M .[J].Angewandte Chemie International Edition,2006,45:5527. |
| [13] | Tang Z;Jiang F;Yu L T;Cui X Gong L Z Mi A Q Jiang Y Z Wu Y D .[J].Journal of the American Chemical Society,2003,125:5262. |
| [14] | Tang, Z;Yang, ZH;Chen, XH;Cun, LF;Mi, AQ;Jiang, YZ;Gong, LZ .A highly efficient organocatalyst for direct Aldol reactions of ketones with aldedydes[J].Journal of the American Chemical Society,2005(25):9285-9289. |
| [15] | 钟琳,肖建良,李灿.多相双功能催化剂上的不对称直接Aldol反应[J].催化学报,2007(08):673-675. |
| [16] | 刘玉霞,杨柳,马志伟,王川川,陶京朝.负载脯氨酸及其衍生物催化的不对称C-C键形成反应研究进展[J].催化学报,2011(08):1295-1311. |
| [17] | Kano T;Takai J;TokudaO;MaruokaK .[J].Angewandte Chemie International Edition,2005,44:3055. |
| [18] | Kano T;Tokuda O;Maruoka K .[J].Tetrahedron Letters,2006,47:7423. |
| [19] | Wu X;He C;Qu S Duan C .[J].Chemical Communications,2011,47:8415. |
| [20] | Zotova N;Franzke A;Armstrong A;Blackmond D G .[J].Journal of the American Chemical Society,2007,129:15100. |
| [21] | Mase N;Tanaka F;Barbas C F Ⅲ .[J].Organic Letters,2003,5:4369. |
| [22] | Tori H;Nakadai M;Ishihara K;Saito S,Yamamoto H .[J].Angewandte Chemie International Edition,2004,43:1983. |
| [23] | Orito Y;Hashimoto S;Ishizuka T;Nakajima M .Chiral base-catalyzed aldol reaction of trimethoxysilyl enol ethers: effect fo water as an additive on stereoselectivities[J].Tetrahedron,2006(2/3):390-400. |
| [24] | Gruttadauria M;Giacalone F;Noto R .[J].Advanced Synthesis and Catalysis,2009,351:33. |
| [25] | Zhou Y;Shan Z .[J].Journal of Organic Chemistry,2006,71:9510. |
| [26] | Ji C;Peng Y;Huang C;Wang N Luo Z Jiang Y .[J].Journal of Molecular Catalysis A:Chemical,2006,246:136. |
| [27] | Parr R G;Yang W.Density Functional Theory of Atoms and Molecules[M].New York:Oxford Univeristy Press,1994 |
| [28] | Becke A D .[J].Journal of Chemical Physics,1993,98:5648. |
| [29] | Lee C;Yang W;Parr R G .[J].Physical Review B:Condensed Matter,1988,37:785. |
| [30] | Zhu, H;Clemente, FR;Houk, KN;Meyer, MP .Rate Limiting Step Precedes C-C Bond Formation in the Archetypical Proline-Catalyzed Intramolecular Aldol Reaction[J].Journal of the American Chemical Society,2009(5):1632-1633. |
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