The thermal decomposition of diazirines: 3-(3-methyldiazirin-3-yl)propan-1-ol and 3-(3-methyldiazirin-3-yl)propanoic acid
作者:Ian D. R. Stevens、Michael T. H. Liu、N. Soundararajan、N. Paike
DOI:10.1039/p29900000661
日期:——
The thermolyses of 3-(3-methyldiazirin-3-yl)propan-1-ol (1) and 3-(3-methyldiazirin-3-yl)propanoic acid (2) have been studied in solution over the temperature range 96–125 °C. The reactions are unimolecular and fit linear Arrhenius plots with K(1)= 1013.85 ± 0.69exp[–31.80 ± 1.21 kcal mol–1/RT]s–1 and K(2)= 1012.38 ± 0.43exp[–29.26 ± 0.75 kcal mol–1/RT]s–1
Synthesis of naphthoquinone antibiotics by intramolecular alkyne cycloaddition to carbene-chromium complexes
作者:M.F. Semmelhack、Joseph J. Bozell、Leonard Keller、Tadahisa Sato、E.J. Spiess、W. Wulff、A. Zask
DOI:10.1016/s0040-4020(01)91420-6
日期:1985.1
The reaction of carbene-chromium complexes with alkynes provides a direct route to naphthoquinone derivatives and is the key step in a new approach to the isochromanone antibiotics exemplified by deoxyfrenolicin (1) and nanaomycin A (2). While the regioselectivity of intermolecular addition of the appropriate unsymmetrical disubstituted alkyne is unfavourable, two successful approaches have been developed
the multistep reaction of N-methyl indole (1 a) with pent-3-yn-1-ol (2 a) in THF at roomtemperature for 2 h to give indole derivative 3 a, which contains a five-membered cyclicether group at C3 in 93% yield. Under similar reaction conditions, various substituted N-methyl indoles 1 b-h and indole (1 i) reacted efficiently with 2 a to afford the corresponding indole derivatives 3 b-h and 3 i in 48-91
PtCl2在室温下有效催化N-甲基吲哚(1a)与戊-3-炔-1-醇(2a)在THF中的多步反应2小时,得到吲哚衍生物3a,其中包含五元C3的环醚基产率为93%。在相似的反应条件下,各种取代的N-甲基吲哚1bh和吲哚(1i)与2a有效反应,以48-91的产率和72%的产率得到相应的吲哚衍生物3bh和3i。结果表明,具有给电子取代基的N-甲基吲哚比具有吸电子基团的那些具有更高的反应活性,提供了更高的产率。同样地,各种取代的but-3-yn-1-ols 2 be和其他长链炔醇2 fi也与N-甲基吲哚(1 a)进行环化加成反应,以提供相应的环化加成产物3 jm和3 a ,3 j和3 no的收率良好至优异。本发明的铂催化的环化-加成反应可以进一步扩展到N-甲基吡咯中。从机理上讲,催化反应是通过炔醇的分子内加氢烷氧基化反应得到环状烯醇醚,然后将吲哚的CH键加到环状烯醇醚的不饱和部分上而提供最终产物。提
Stereochemical aspects of intramolecular palladium catalysed [3+2] cycloadditions of methylenecyclopropanes
The preparation and intramolecularpalladiumcatalysed [3+2] cycloaddition reactions of a range of substrates containing either stereochemically defined 2,3-disubstituted methylenecyclopropanes 3 or acrylate acceptors 12–15 are described. Evidence is presented which supports the hypothesis that these cycloaddition reactions proceed via palladium-trimethylenemethane type intermediates and that the two
Nickel(0)-catalyzed synthesis of substituted phenols from cyclobutenones and alkynes
作者:Mark A. Huffman、Lanny S. Liebeskind
DOI:10.1021/ja00007a072
日期:1991.3
The results above show that the convergent synthesis of substituted phenols is possible by nickel(0)-catalyzed ring opening and cycloaddition of cyclobutenones with alkynes. Future efforts will explore application of this method to intramolecular reactions