丙二烯

銅催化下羧酸炔丙酯在強堿作用下生成端基丙二烯的反應(yīng)。另外在銅金屬催化劑、多聚甲醛、高位阻2級胺(二環(huán)己胺、二異丙胺等)存在下，末端炔烴也可以得到端基丙二烯。

Crabbe聯(lián)烯合成受限于多聚甲醛，其他醛不能生成聯(lián)烯。2010年麻生明及其研究團(tuán)隊報道了新的合成方法，在廉價的的 ZnI2和嗎啡啉存在下，由醛和端基炔合成了1,3-二取代聯(lián)烯。

【Kuang, J.; Ma, S. J. Am. Chem. Soc.2010, 132, 1786.】

反應(yīng)機理

端基炔和多聚甲醛反應(yīng)機理：

Allene (3). To PhSCu (4.41 g, 25.5 mmol) in Et2O (100 mL) at 35 C was added 2.47 M BuLi in hexane (9.91 mL, 2.45 mmol). After 20 min at -30 C, 1 (2.26 g, 10.2 mmol) in Et2O (35 mL) was added dropwise at -78 C. After 1 h stirring, the mixture was quenched with 2 mL of sat NH4Cl at a rate of 0.16 mL/min. After 6 h at 78 C, the solids were filtered at r.t.. The organic phase after washing, evaporation and chromatography afforded 1.51 g of 3 (91%).

【Normant JF, Tet Lett., 1976, 2313】

1 Crabbe′ P J Chem Soc Chem Comm 1976 183

2 Normant JF Tet Lett 1976 2313

3 Nantz MH Synthesis 1993 577

4 Hiemstra H J Org Chem 1997 62 8862

5 Takeda T Org Biomol Chem 2005 3 2914

6 Takahashi T J Org Chem 2005 70 8785

7 Crabbé, P.; Fillion, H.; André, D.; Luche, J.-L. J. Chem. Soc. Chem. Commun. 1979, 859.

8 Kuang, J.; Ma, S. J. Org. Chem. 2009, 74, 1763.

9 Kitagaki, S.; Komizu, M.; Mukai, C. Synlett 2011, 1129.

編譯自：Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, Page 105.

1,3-丙二胺基鉀作用下，非端基炔通過丙二烯中間體異構(gòu)化為端基炔的反應(yīng)。整個異構(gòu)化的過程，炔基像拉鏈一樣，從鏈中異構(gòu)化到鏈端，因此此反應(yīng)也被稱為炔基拉鏈反應(yīng)。此反應(yīng)最早由Charles Allen Brown和Ayako Yamashita在1975年首先報道【 J. Am. Chem. Soc. 97(4): 891–892】。此反應(yīng)常見的底物是長鏈的炔醇，堿最開始是將KH加入到1,3-丙二胺溶劑中得到直接用于反應(yīng)。由于KH比較危險，后來也發(fā)展出了替代方法：利用1,3-丙二胺的鋰鹽和叔丁醇鉀進(jìn)行反應(yīng)。

反應(yīng)機理

16-Heptadecyn-1-ol (2).A mixture of potassium (190 mg, 4.8 mmol) in 1,3-propanediamine (5 mL) with ferric nitrate (1 mg) was heated to 90 C in an ultrasound cleaning bath. After 10–15 min, potassium disappeared and a green–brown solution of KAPA was formed which was cooled to 0 C and

12-heptadecyn-1-ol (1, 190 mg, 0.75 mmol) in THF (1 mL) was added. After 30 min stirring at 0 C, the mixture was poured into H2O (125 mL) and extracted with hexane (3 100 mL). The extract was dried (MgSO4) and evaporated to yield 185 mg of 16-heptadecyn-1-ol (2, 98%), mp 41 C.

【Becker D, J Org Chem., 1984, 49, 2494】

23-Tetracosyn-1-ol (4).1,3-Diaminopropane (10 mL) under N2 was treated with Li (140 mg, 20 mmol) under heating (70 C) and stirring. After 2 h, the mixture was cooled to 20 C, KOt-Bu (1.3 g, 12 mmol) was added and stirring was continued for another 15 min when 7-tetracosyn-1-ol (3, 1.05 g, 3 mmol) was added. After 2 h stirring the mixture was quenched with water and usual workup gave after chromatography (silica gel, hexane:Et2O 1:1) 860 mg of 4 (82%), mp 76 C.

【Abrams SR, Can J Chem., 1984, 62, 1333】

相關(guān)文獻(xiàn)

1 Brown CA J Am Chem Soc 1975 97 891

2 Brown CA J Chem Soc Chem Commun 1976 959

3 Macaulay SR J Org Chem 1980 45 734

4 Becker D J Org Chem 1984 49 2494

5 Abrams SR Can J Chem 1984 62 1333

6 Shaw AC Org Synth Coll Vol 1988 8 146

7 Balova IA Russ J Org Chem 2003 39 1613

8 Balova IA Eu J Org Chem 2005 882

編譯自：Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, Page 63-64.