卡罗尔重排反应

卡罗尔重排反应（英语：Carroll rearrangement），又称卡罗尔-克莱森重排反应，指β-酮酸烯丙酯发生克莱森重排反应产生α-烯丙基-β-酮酸，再经脱羧，得到γ,δ-不饱和酮。^[1]

反应机理

反应最初是用碱催化，采用一锅反应，即酯交换（制取β-酮酯）-卡罗尔重排串联进行，需要苛刻条件（乙酸钠，170－240℃）。其机理为烯醇发生的克莱森重排然后脱羧（下图A途径）。现多采用分步方法进行，主要改进包括双负离子法（用二异丙基氨基锂生成双负离子，然后在室温或回流下重排，由此得到的酮酸较易分离）^[2]^[3]以及负载在氯化铝上无溶剂条件下的反应^[4]。

1980年辻二郎对此反应作了改进，他用钯(0)作催化剂，经过生成中间体烯丙基正离子／羧酸根负离子有机金属配合物，然后脱羧和烯丙基化，实现了温和条件下的卡罗尔重排（下图B途径）。^[5]

下面用四(三苯基膦)钯(0)催化的实验证实了脱羧一步是在烯丙化前发生。^[6]

不对称脱羧烯丙化反应

使用手性配体的不对称卡罗尔重排也有发展。^[7] 首个不对称重排由 Burger 等在 2004 年报道，是以三(二亚苄基丙酮)二钯(0)和Trost配体催化：^[6]

桑野良一等报道了萘酚存在下的卡罗尔重排，反应ee可达88%，但缺点是底物必须要含乙酰氨基基团。^[8]

又如如下对映归一性合成：^[9]

不对称卡罗尔重排也可拓展至烯醇的碳酸酯发生的α-烯丙基化。^[10]

参见

参考资料

^ Carroll, M. F. 131. Addition of α,β-unsaturated alcohols to the active methylene group. Part I. The action of ethyl acetoacetate on linalool and geraniol. J. Chem. Soc. 1940: 704–706. doi:10.1039/JR9400000704.
^ J. F. Genus, D. D. Peters, J-F. Ding, T. A. Bryson. The Dianion Carroll Rearrangement - A Cyclic Application. Synlett. 1994: 209–210. doi:10.1055/s-1994-22797.
^ Stephen R. Wilson, Martyn F. Price. The ester enolate Carroll rearrangement. J. Org. Chem. 1984, 49 (4): 722–725. doi:10.1021/jo00178a036.
^ S. I. Pogrebnoi, Y. B. Kalyan, M. Z. Krimer, W. A. Smit. Carrol rearrangement on the surface of chromatographic grade alumina. Tetrahedron Lett. 1987, 28 (41): 4893–4896. doi:10.1016/S0040-4039(00)96654-1.
^ Isao Shimizu, Toshiro Yamada and Jiro Tsuji. Palladium-catalyzed rearrangement of allylic esters of acetoacetic acid to give γ,δ-unsaturated methyl ketones. Tetrahedron Letters. 1980, 21 (33): 3199–3202. doi:10.1016/S0040-4039(00)77444-2.
^ ^6.0 ^6.1 Erin C. Burger and Jon A. Tunge. Asymmetric Allylic Alkylation of Ketone Enolates: An Asymmetric Claisen Surrogate. Org. Lett. 2004, 6 (22): 4113–4115. doi:10.1021/ol048149t.
^ Shu-Li You and Li-Xin Dai. Enantioselective Palladium-Catalyzed Decarboxylative Allylic Alkylations. Angew. Chem. Int. Ed. 2006, 45 (32): 5246–5248. doi:10.1002/anie.200601889.
^ Kuwano, R.; Ishida N.; Murakami, M. Asymmetric Carroll rearrangement of allyl α-acetamido-β-ketocarboxylates catalysed by a chiral palladium complex. Chem. Commun. 2005, (31): 3951–3952. doi:10.1039/b505105c. .
^ Justin T. Mohr, Douglas C. Behenna, Andrew M. Harned, and Brian M. Stoltz. Deracemization of Quaternary Stereocenters by Pd-Catalyzed Enantioconvergent Decarboxylative Allylation of Racemic β-Ketoesters. Angew. Chem. Int. Ed. 2005, 44 (42): 6924–6927. doi:10.1002/anie.200502018.
^ Barry M. Trost and Jiayi Xu. Palladium-Catalyzed Asymmetric Allylic α-Alkylation of Acyclic Ketones. J. Am. Chem. Soc. 2005, 127 (49): 17180–17181. doi:10.1021/ja055968f.

[1] Carroll, M. F. 131. Addition of α,β-unsaturated alcohols to the active methylene group. Part I. The action of ethyl acetoacetate on linalool and geraniol. J. Chem. Soc. 1940: 704–706. doi:10.1039/JR9400000704.

[2] J. F. Genus, D. D. Peters, J-F. Ding, T. A. Bryson. The Dianion Carroll Rearrangement - A Cyclic Application. Synlett. 1994: 209–210. doi:10.1055/s-1994-22797.

[3] Stephen R. Wilson, Martyn F. Price. The ester enolate Carroll rearrangement. J. Org. Chem. 1984, 49 (4): 722–725. doi:10.1021/jo00178a036.

[4] S. I. Pogrebnoi, Y. B. Kalyan, M. Z. Krimer, W. A. Smit. Carrol rearrangement on the surface of chromatographic grade alumina. Tetrahedron Lett. 1987, 28 (41): 4893–4896. doi:10.1016/S0040-4039(00)96654-1.

[5] Isao Shimizu, Toshiro Yamada and Jiro Tsuji. Palladium-catalyzed rearrangement of allylic esters of acetoacetic acid to give γ,δ-unsaturated methyl ketones. Tetrahedron Letters. 1980, 21 (33): 3199–3202. doi:10.1016/S0040-4039(00)77444-2.

[Burger-6] 6.0 ^6.1 Erin C. Burger and Jon A. Tunge. Asymmetric Allylic Alkylation of Ketone Enolates: An Asymmetric Claisen Surrogate. Org. Lett. 2004, 6 (22): 4113–4115. doi:10.1021/ol048149t.

[7] Shu-Li You and Li-Xin Dai. Enantioselective Palladium-Catalyzed Decarboxylative Allylic Alkylations. Angew. Chem. Int. Ed. 2006, 45 (32): 5246–5248. doi:10.1002/anie.200601889.

[8] Kuwano, R.; Ishida N.; Murakami, M. Asymmetric Carroll rearrangement of allyl α-acetamido-β-ketocarboxylates catalysed by a chiral palladium complex. Chem. Commun. 2005, (31): 3951–3952. doi:10.1039/b505105c. .

[9] Justin T. Mohr, Douglas C. Behenna, Andrew M. Harned, and Brian M. Stoltz. Deracemization of Quaternary Stereocenters by Pd-Catalyzed Enantioconvergent Decarboxylative Allylation of Racemic β-Ketoesters. Angew. Chem. Int. Ed. 2005, 44 (42): 6924–6927. doi:10.1002/anie.200502018.

[10] Barry M. Trost and Jiayi Xu. Palladium-Catalyzed Asymmetric Allylic α-Alkylation of Acyclic Ketones. J. Am. Chem. Soc. 2005, 127 (49): 17180–17181. doi:10.1021/ja055968f.

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