腈鈉

腈鈉是指腈類化合物和鈉離子形成的鹽，這類鹽被認為是反應中存在的中間體。腈鈉可由腈和氨基鈉、取代氨基鈉或金屬鈉反應得到。但由於腈鈉的高度不穩定性，其固體的分離特別困難。^[1]

乙腈鈉[編輯]

乙腈鈉（NaCH₂CN，M_r＝63.0）被認為是一種白色固體，可由乙腈和NaN(SiMe₃)₂反應得到：^[2]

CH₃CN + 3 NaN(SiMe₃)₂ —^乙醚→ NaCH₂CN + HN(SiMe₃)₂ + 2 NaN(SiMe₃)₂

該反應中，乙腈只有1個氫原子被鈉取代。

由於乙腈的α-H具有一定的酸性，因此與氨基鈉在液氨中反應，生成了一種被認為是NaCH₂CN·xNH₃或(CH₂CN)^-Na⁺·xNH₃的產物。但當這種化合物在液氨中結晶時，產生的卻是CH₃C(=NH)NHNa（脒的鈉鹽）。^[3]

乙腈鈉可以和鹵代烴反應：

NaCH₂CN + RX → NaX + RCH₂CN

苯乙腈鈉[編輯]

苯乙腈鈉（C₁₆H₁₃N₂Na，M_r＝256.3）可由苯乙腈和金屬鈉直接反應得到，其產物為二聚體的鈉鹽：^[1]

3 C₆H₅CH₂CN + 2 Na → NaCN + C₆H₅CH₃ + C₁₆H₁₃N₂Na

Fred等認為苯乙腈鈉的結構應該是(C₆H₅)HC=C=N-Na（M_r＝139.1）^[4]：

2 (C₆H₅)H-C=C=N-H + 2 Na → 2 (C₆H₅)H-C=C=N-Na

(C₆H₅)H-C=C=N-Na + H₂ → C₆H₅CH₃ + NaCN （副反應）

其化學性質活潑，高溫下發生分解反應，產生二苯乙烯和氰化鈉

2 (C₆H₅)H-C=C=N-Na → NaCN + (C₆H₅)H-C=C-H(C₆H₅)

它和空氣中的氧氣反應，得到苯甲酸和氰化鈉：

2 (C₆H₅)H-C=C=N-Na + O₂ → C₆H₅COOH + NaCN

它和硝酸銀在無水乙醇中反應，得到相應的銀鹽。

腈的其它金屬鹽[編輯]

乙腈和叔丁基鋰反應，可以得到Li₂CHCN。^[2]

苯乙腈和鉀的反應可以得到相應的鉀鹽，反應按如下方程式發生：^[5]

2 C₆H₅CH₂CN + 2 K → 2 C₆H₅HC=C=NK + H₂

產物C₆H₅HC=C=NK對水蒸氣和二氧化碳敏感，酸會將其分解，放出氰化氫。它和(C₆H₅)(CN)HCK有着互變異構，雖然該異構體不佔主導，但能夠和碘乙烷反應，產生該異構體的取代物：

(C₆H₅)(CN)HCK + C₂H₅I → (C₆H₅)(CN)HC(C₂H₅) + KI

腈的鎂、銅^[6]、鋅鹽^[7]也被製得，它們和鈉鹽一樣，都是很強的親核試劑。這些腈的金屬鹽中碳氮鍵的三鍵性質之外，通過X射線分析，還有部分碳碳雙鍵的性質。^[8]

參考文獻[編輯]

^ ^1.0 ^1.1 Mary M. Rising, Tsoh-Wu Zee. SODIUM SALTS OF AROMATIC NITRILES. I. J. Am. Chem. Soc., 1928, 50 (6), pp 1699–1707. DOI: 10.1021/ja01393a028
^ ^2.0 ^2.1 Robert West, Gerald A. Gornowicz. Polylithium compounds. IV. Polylithiation of nitriles and the preparations of trisilyl ynamines. J. Am. Chem. Soc., 1971, 93 (7), pp 1714–1720. DOI: 10.1021/ja00736a025
^ F. W. Bergstrom, Robert Agostinho. The Alkylation and Arylation of Aliphatic Nitriles in Liquid Ammonia. J. Am. Chem. Soc., 1945, 67 (12), pp 2152–2154. DOI: 10.1021/ja01228a025
^ Fred W. Upson, Robert T. Maxwell, Howard M. Parmelee. STRUCTURE OF THE SALTS OF AROMATIC NITRILES. J. Am. Chem. Soc., 1930, 52 (5), pp 1971–1975. DOI: 10.1021/ja01368a031
^ Mary M. Rising, Irving E. Muskat, Edmund W. Lowe. SALTS OF AROMATIC NITRILES. II. POTASSIUM PHENYLACETONITRILE. J. Am. Chem. Soc., 1929, 51 (1), pp 262–265. DOI: 10.1021/ja01376a033
^ Matthew Purzycki, Wang Liu, Göran Hilmersson, et al. Metalated nitriles: N- and C-coordination preferences of Li, Mg, and Cu cations. Chem. Commun., 2013,49, 4700-4702. DOI: 10.1039/C3CC41703D
^ Xun Yang, Dinesh Nath, and Fraser F. Fleming. Chemoselective Alkylations with N- and C-Metalated Nitriles. Org. Lett., 2015, 17 (19), pp 4906–4909 DOI: 10.1021/acs.orglett.5b02481
^ Fraser F. Fleming , Zhiyu Zhang , Wang Liu, et al. Metalated Nitriles: Organolithium, -magnesium, and -copper Exchange of α-Halonitriles. J. Org. Chem., 2005, 70 (6), pp 2200–2205. DOI: 10.1021/jo047877r

[Rising-1] 1.0 ^1.1 Mary M. Rising, Tsoh-Wu Zee. SODIUM SALTS OF AROMATIC NITRILES. I. J. Am. Chem. Soc., 1928, 50 (6), pp 1699–1707. DOI: 10.1021/ja01393a028

[West-2] 2.0 ^2.1 Robert West, Gerald A. Gornowicz. Polylithium compounds. IV. Polylithiation of nitriles and the preparations of trisilyl ynamines. J. Am. Chem. Soc., 1971, 93 (7), pp 1714–1720. DOI: 10.1021/ja00736a025

[Berg-3] F. W. Bergstrom, Robert Agostinho. The Alkylation and Arylation of Aliphatic Nitriles in Liquid Ammonia. J. Am. Chem. Soc., 1945, 67 (12), pp 2152–2154. DOI: 10.1021/ja01228a025

[4] Fred W. Upson, Robert T. Maxwell, Howard M. Parmelee. STRUCTURE OF THE SALTS OF AROMATIC NITRILES. J. Am. Chem. Soc., 1930, 52 (5), pp 1971–1975. DOI: 10.1021/ja01368a031

[5] Mary M. Rising, Irving E. Muskat, Edmund W. Lowe. SALTS OF AROMATIC NITRILES. II. POTASSIUM PHENYLACETONITRILE. J. Am. Chem. Soc., 1929, 51 (1), pp 262–265. DOI: 10.1021/ja01376a033

[6] Matthew Purzycki, Wang Liu, Göran Hilmersson, et al. Metalated nitriles: N- and C-coordination preferences of Li, Mg, and Cu cations. Chem. Commun., 2013,49, 4700-4702. DOI: 10.1039/C3CC41703D

[7] Xun Yang, Dinesh Nath, and Fraser F. Fleming. Chemoselective Alkylations with N- and C-Metalated Nitriles. Org. Lett., 2015, 17 (19), pp 4906–4909 DOI: 10.1021/acs.orglett.5b02481

[8] Fraser F. Fleming , Zhiyu Zhang , Wang Liu, et al. Metalated Nitriles: Organolithium, -magnesium, and -copper Exchange of α-Halonitriles. J. Org. Chem., 2005, 70 (6), pp 2200–2205. DOI: 10.1021/jo047877r

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