氮杂环卡宾铜配合物高选择性催化端炔、CO_2及烯丙基氯羧化偶联反应研究
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摘要
作为造成全球气候变暖的主要温室气体及储量丰富、廉价易得的可再生性碳资源的CO2,其催化转化合成有用的有机化合物的研究受到极大的关注。CO2可作为亲电试剂与碳亲核试剂进行羧化反应制备有机羧酸或羧酸酯。过渡金属催化的有机硼、有机锌及有机铜等反应活性较低的亲核试剂与CO2的羧化反应是合成官能团羧酸及羧酸酯有效的方法。相比于过渡金属催化的CO2作为羧化试剂的的羧化反应,由于容易形成直接偶联副产物,过渡金属配合物催化的亲核试剂,CO2及亲电试剂三组分羧化偶联反应高选择性制备羧酸酯的研究很少。运用CO2作为羧化试剂的羧化偶联反应高选择性地合成羧酸酯是具有挑战性的研究课题。
在羧化偶联反应机理认识的基础上,本论文构建了端炔,CO2及烯丙基氯类化合物的三组分新羧化偶联反应体系。用苯乙炔,CO2与肉桂基氯的羧化偶联反应为模式反应筛选出氮杂环卡宾配合物(IPr)CuCl为最优催化剂。探索了此反应的最佳反应条件：CO2(1.5 MPa),(IPr)CuCl(10 mol%),K2CO3(2 equiv.),DMF,60℃,24 h。研究发现氮杂环卡宾配合物(IPr)CuCl可高效催化一系列端炔,CO2及烯丙基氯类化合物的三组分羧化偶联反应,高产率、高选择性地得到包含一系列官能团的炔酸酯。氮杂环卡宾配合物催化剂(IPr)CuCl在羧化偶联反应后可通过简单柱层析分离回收再利用,并在以后使用中保持高催化活性及高选择性。
Catalytic transformations of carbon dioxide (CO2) to useful organic compounds have gained considerable attentions due to its main contribution to global warming and its potential use as an abundant, inexpensive and renewable C1 source. CO2 usually serves as electrophile in the carboxylation of nucleophilic organometallic reagents to synthesize carboxylic acid and esters. Transition-metal-catalyzed carboxylation of less reactive carbon nucleophiles such as organoboron and organozinc reagents represents an effective method to access carboxylic acid and esters bearing various functional groups. Compared with transition-metal-catalyzed carboxylation using CO2 as carboxylative reagent, transition-metal-catalyzed carboxylative coupling of nucleophile, CO2 and electrophile to selectively synthesize carboxylic acid esters was rarely reported because of the easily formed by-product from the cross-coupling. Therefore, highly selective synthesis of carboxylic acid ester by the carboxylative coupling using CO2 as carboxylative reagent is a promising challenge issue.
On the basis of the mechanistic insight of carboxylative coupling reaction, this work designed a new reaction system for the carboxylative coupling of terminal alkynes, CO2 and allylic compounds. The carboxylative coupling reaction of phenylacetylene, CO2 and cinnamyl chloride was chosen as a model reaction and N-heterocyclic carbene copper(Ⅰ) complex (IPr)CuCl was identified as best catalyst. Screening of reaction parameters established the optimum conditions:CO2 (1.5 MPa), (IPr)CuCl (10 mol%), K2CO3 (2 equiv.), DMF,60℃,24 h.N-heterocyclic carbene copper(Ⅰ) complex (IPr)CuCl proved to be a highly active catalyst for the carboxylative coupling of various terminal alkynes, CO2 and allylic chlorides to selectively afford various functionalized allylic 2-alkynoates in good yield. The catalyst (IPr)CuCl can be easily recovered in high yield after the reaction by simple chromatography without any loss in activity and product selectivity.
在羧化偶联反应机理认识的基础上,本论文构建了端炔,CO2及烯丙基氯类化合物的三组分新羧化偶联反应体系。用苯乙炔,CO2与肉桂基氯的羧化偶联反应为模式反应筛选出氮杂环卡宾配合物(IPr)CuCl为最优催化剂。探索了此反应的最佳反应条件：CO2(1.5 MPa),(IPr)CuCl(10 mol%),K2CO3(2 equiv.),DMF,60℃,24 h。研究发现氮杂环卡宾配合物(IPr)CuCl可高效催化一系列端炔,CO2及烯丙基氯类化合物的三组分羧化偶联反应,高产率、高选择性地得到包含一系列官能团的炔酸酯。氮杂环卡宾配合物催化剂(IPr)CuCl在羧化偶联反应后可通过简单柱层析分离回收再利用,并在以后使用中保持高催化活性及高选择性。
Catalytic transformations of carbon dioxide (CO2) to useful organic compounds have gained considerable attentions due to its main contribution to global warming and its potential use as an abundant, inexpensive and renewable C1 source. CO2 usually serves as electrophile in the carboxylation of nucleophilic organometallic reagents to synthesize carboxylic acid and esters. Transition-metal-catalyzed carboxylation of less reactive carbon nucleophiles such as organoboron and organozinc reagents represents an effective method to access carboxylic acid and esters bearing various functional groups. Compared with transition-metal-catalyzed carboxylation using CO2 as carboxylative reagent, transition-metal-catalyzed carboxylative coupling of nucleophile, CO2 and electrophile to selectively synthesize carboxylic acid esters was rarely reported because of the easily formed by-product from the cross-coupling. Therefore, highly selective synthesis of carboxylic acid ester by the carboxylative coupling using CO2 as carboxylative reagent is a promising challenge issue.
On the basis of the mechanistic insight of carboxylative coupling reaction, this work designed a new reaction system for the carboxylative coupling of terminal alkynes, CO2 and allylic compounds. The carboxylative coupling reaction of phenylacetylene, CO2 and cinnamyl chloride was chosen as a model reaction and N-heterocyclic carbene copper(Ⅰ) complex (IPr)CuCl was identified as best catalyst. Screening of reaction parameters established the optimum conditions:CO2 (1.5 MPa), (IPr)CuCl (10 mol%), K2CO3 (2 equiv.), DMF,60℃,24 h.N-heterocyclic carbene copper(Ⅰ) complex (IPr)CuCl proved to be a highly active catalyst for the carboxylative coupling of various terminal alkynes, CO2 and allylic chlorides to selectively afford various functionalized allylic 2-alkynoates in good yield. The catalyst (IPr)CuCl can be easily recovered in high yield after the reaction by simple chromatography without any loss in activity and product selectivity.
引文
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[41]Tudose A., Demonceau A., Delaude L. Imidazol(in)ium-2-carboxylates as N-heterocyclic carbene precursors in ruthenium-arene catalysts for olefin metathesis and cyclopropanation [J] J. Organomet. Chem.,2006,691:5356-5365.
[42]Wang H M. J. Lin I J B. Facile synthesis of silver(I)-carbene complexes. useful carbene transfer agents [J] Organomet.,1998,17:972-975.
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[2]Leitner W. The coordination chemistry of carbon dioxide and its relevance for catalysis:a crtical survey [J]. Coord. Chem. Rev.,1996,153:257-284.
[3]Gibson D H. The organometallic chemistry of carbon dioxide [J]. Chem. Rev.,1996,96: 2063-2095.
[4]Yin X L, Moss J R. Recent developments in the activation of carbon dioxide by metal complexes [J]. Coord. Chem. Rev.,1999,181:27-59.
[5]Arakawa H., Aresta M., Armor J N. et al. Catalysis research of relevance to carbon management: Progress, Challenges, and Opportunities [J]. Chem. Rev.,2001,101:953-996.
[6]Sakakura T., Choi J C., Yasuda H. Transformation of carbon dioxide [J]. Chem. Rev.,2007,107: 2365-2387.
[7]Saito S., Nakagawa S. Yamamoto Y. et al. Nickel-mediated regio-and chemoselective carboxylation of alkynes in the presence of carbon dioxide [J].J. Org. Chem.,1999,64: 3975-3978.
[8]Takimoto M., Mori M. Cross-coupling reaction of Oxo-π-allylnickel complex generated from 1,3-diene under an atmosphere of carbon dioxide [J] J. Am. Chem. Soc.,2001,123:2895-2896.
[9]Shimizu K. Takimoto M. Mori M. et al. Nickel-catalyzed regioselective synthesis of tetrasubstituted alkene using alkylative carboxylation of disubstituted alkyne [J] Org. Lett.,2005, 7:195-197.
[10]Takimoto M., Nakamura Y. Mori M. et al. Highly enantioselective catalytic carbon dioxide incorporation reaction:nickel-catalyzed asymmetric carboxylative cyclization of bis-1,3-dienes [J] J. Am. Chem. Soc.,2004,126:5956-5957.
[11]Takaya J., Iwasawa N. Hydrocarboxylation of allenes with CO2 catalyzed by silyl pincer-type palladium complex [J] J. Am. Chem. Soc,2008,130:15254-15255.
[12]Williams C M., Johnson J B., Rovis T. Nickel-catalyzed reductive carboxylation of styrenes using CO2 [J] J. Am. Chem. Soc.,2008,130,14936-14937.
[13]Yoshida H., Morishita T., Ohshita J. Direct access to anthranilic acid derivatives via CO2 incorporation reaction using arynes [J] Org. Lett.,2008,10:3845-3847.
[14]Shi M., Nicholas K M. Palladium-catalyzed carboxylation of allyl stannanes [J] J. Am. Chem. Soc.,1997,119:5057-5058.
[15]Ukai K., Aoki M., Iwasawa N. et al. Rhodium(I)-catalyzed carboxylation of aryl- and alkenylboronic esters with CO2 [J] J. Am. Chem. Soc.,2006,128:8706-8707.
[16]Ohishi T., Nishiura M., Hou Z. Carboxylation of organoboronic esters catalyzed by N-Heterocyclic Carbene Copper(Ⅰ) complexes [J] Angew. Chem. Int. Ed.,2008,47:5792-5795
[17]Takaya J., Tadami S., Iwasawa N. et al. Copper(Ⅰ)-catalyzed carboxylation of aryl- and alkenylboronic esters [j] Org. Lett.,2008,10:2697-2700.
[18]Yeung C S., Dong V M. Beyond Aresta's complex:Ni- and Pd-catalyzed organozinc coupling with CO2 [J] J. Am. Chem. Soc.,2008,130:7826-7827.
[19]Krasovskiy A., Malakhov V., Knochel P.et al. Efficient synthesis of functionalized organozinc compounds by the direct insertion of zinc into organic iodides and bromides [J] Angew. Chem. Int. Ed.,2006,45:6040-6044.
[20]Ochiai H., Yorimitsu H., Oshima K. et al. Nickel-catalyzed carboxylation of organozinc reagents with CO2 [J] Org. Lett.,2008,10:2681-2683.
[21]Correa A., Martin R. Palladium-catalyzed direct carboxylation of aryl bromides with carbon dioxide [J] J. Am. Chem. Soc.,2009,131:15974-15975.
[22]Franks R J., Nicholas K M. Palladium-catalyzed carboxylative coupling of allylstannanes and allyl halides [J] Organometallics,2000,19:1458-1460.
[23]Behr A., Brehme V A. Homogeneous and heterogeneous catalyzed three-step synthesis of 2-ethylheptanoic acid from carbon dioxide, butadiene and hydrogen [J] J. Mol. Catl. A:Chem., 2002,187:69-80.
[24]Takimoto M., Kawamura M., Mori M. Nickel(0)-mediated sequential addition of carbon dioxide and aryl aldehydes into terminal allenes [J] Org. Lett.,2003,5:2599-2601.
[25]Louie J., Gibby J E., Tekavec T N. et al. Efficient nickel-catalyzed [2+2+2] cycloaddition of CO2 and diynes [J] J. Am. Chem. Soc.,2002,124:15188-15189.
[26]Yoshida H., Fukushima H., Kunai A. CO2 incorporation reaction using arynes:straightforward access to benzoxazinone [J] J. Am. Chem. Soc.,2006,128:11040-11041.
[27]Fukue Y., Oi S., Inoue Y. Direct synthesis of alkyl-2-alkynoates from alk-1-ynes, CO2, and bromoalkanes catalysed by copper(Ⅰ) or silver(Ⅰ) salt [J] J. Chem. Soc., Chem. Commun.1994, 2091
[28]Eghbali N., Eddy J., Anastas P T. Silver-catalyzed one-pot synthesis of arylnaphthalene lactones [J] J. Org. Chem.,2008,73:6932-6935.
[29]Ma S., Lu X. Stereoselective synthesis of a-(chloromethylene)-ybutyrolactone derivatives from acyclic allylic 2-alkynoates [J] J. Org. Chem.,1993,58:1245-1250.
[30]Zhang Q., Lu X., Han X. Palladium(Ⅱ)-catalyzed asymmetric cyclization of (Z)-4'-acetoxy-2'-butenyl 2-alkynoates. role of nitrogen-containing ligands in palladium(Ⅱ)-mediated reactions [J] J. Org. Chem.,2001,66:7676-7684.
[31]Rayabarapu D K., Tunge J A. Catalytic decarboxylative sp-sp3 coupling [J] J. Am. Chem. Soc., 2005,127:13510-13511.
[32]Yin G., Liu G. Palladium-catalyzed oxidative cyclization of enynes with hydrogen peroxide as the oxidant [J] Angew. Chem.,2008,120:5522-5525.
[33]Yin G., Liu G. Palladium-catalyzed oxidative cyclization of enynes with hydrogen peroxide as the oxidant [J] Angew. Chem. Int. Ed.,2008,47:5442-5445.
[34]Pi S., Li J., Liang Y Palladium-catalyzed decarboxylative coupling of allylic alkynoates with arynes [J] Org. Lett.,2009,11:2309-2312.
[35]Fang X., Li C., Tong X. Rhodium-catalyzed cycloaddition of 1,6-enynes with 2-bromophenylboronic acids:synthesis of a multi-substituted dihydronaphthalene scaffoldw [J] Chem. Commun.,2009,5311-5313.
[36]Lee Y T., Kang Y K., Chung Y K. Au(I)-catalyzed cycloisomerization reaction of amide-or ester-tethered 1,6-enynes to bicyclo[3.2.0]hept-6-en-2-ones [J] J. Org. Chem.,2009,74: 7922-7934.
[37]Arduengo III A J., Krafczyk R., Schmutzler R. Imidazolyidenes, imidazolinylidenes and imidazolidines [J] Tetrahedron,1999,55 14523-14534.
[38]Jurkauskas V., Sadighi J P., Buchwald S L. Conjugate reduction of α,β-unsaturated carbonyl compounds catalyzed by a copper carbene complex [J] Org. Lett.,2003,5:2417-2430.
[39]Duong H A., Tekavec T N., Louie J. Reversible carboxylation of N-heterocyclic carbenes [J] Chem. Commun.,2004,112-113.
[40]Voutchkova A M., Eisenstein O., Crabtree R H. Imidazolium carboxylates as versatile and selective N-heterocyclic carbene transfer agents:synthesis,rnechanism, and applications [J] J.Am. Chem. Soc.,2007,129,:12834-12846.
[41]Tudose A., Demonceau A., Delaude L. Imidazol(in)ium-2-carboxylates as N-heterocyclic carbene precursors in ruthenium-arene catalysts for olefin metathesis and cyclopropanation [J] J. Organomet. Chem.,2006,691:5356-5365.
[42]Wang H M. J. Lin I J B. Facile synthesis of silver(I)-carbene complexes. useful carbene transfer agents [J] Organomet.,1998,17:972-975.
[43]Grushin V V., Alper H. Copper(1) and phase transfer catalyzed allylation of alkynes [J] J. Org. Chem.,1992,57:2188-2192.
[44]Larsen C H., Anderson K W., Buchwald S L. Palladium-catalyzed heck alkynylation of benzyl chlorides [J] Synlett.,2006,18:2941-2946.
[45]Bieber L W., da Silva M F. Copper catalyzed regioselective coupling of allylic halides and alkynes promoted by weak inorganic bases [J] Tetrahedron Lett.,2007,48:7088-7090.
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