在 pH 5 到 0 的范围内对 CC 1065 A 环的 2-取代衍生物进行了 pH 速率研究。目标是记录接近中性的一般酸催化环丙基开环的存在,并评估2-取代基对环丙基环捕获亲核试剂速率的作用。我们的研究表明,环丙基在 pH 值高于 4 时会经历可逆的一般酸/碱催化捕获氯化物亲核试剂。这一发现表明 A 环对 DNA 小沟的一般酸催化烷基化是可行的。pH 速率研究还表明,2-取代基不影响 A 环质子化羰基的 pKa(pKa 约为 1),并且对亲核试剂捕获速率的影响相对较小。这一发现与显示稠合吡咯并环作为羰基氧电子密度来源的计算一致。另一方面,2-氮仅向 2-取代基的羰基释放电子,并且不会显着影响 A 环环丙基对亲核试剂的捕获。
Synthesis of cycloprop[c]indol-5-ones from 4-diazo-3-[n-(2-propenyl)amido]cyclohexadien-1-ones. Exploration of copper(I) and copper(II) complexes as catalysts
作者:Richard J. Sundberg、William J. Pitts
DOI:10.1021/jo00009a023
日期:1991.4
The cyclization of 4-diazo-3-[N-(2-propenyl)amido]cyclohexadienones to cycloprop[c]indol-5-ones under the influence of copper(I) and copper(II) compounds has been investigated. Catalysis is observed with copper(I) triflate, the carbon monoxide complex of copper(I) triflate, and the carbon monoxide complexes of trifluoropentanedionato- and hexafluoropentanedionatocopper(I). The best results, essentially quantitative conversion, are achieved with a catalyst solution containing trifluoropentanedionatocopper(I) carbonyl and 1 equiv of n-butylamine. No significant enantioselectivity is observed with a chiral salicyliminatocopper(II), [(trifluoroacetyl)camphorato]copper(I) carbonyl, or a trifluoropentanedionatocopper(I) carbonyl solution containing (S)-alpha-naphthylethylamine. A mechanistic interpretation involving reductive dediazonization, exo-trig radical cyclization, and cyclopropane formation by the resulting intermediate is proposed.
WARPEHOSKI, M. A.;GEBHARD, I.;KELLY, R. C.;KRUEGER, W. C.;LI, L. H.;MCGOV+, J. MED. CHEM., 31,(1988) N 3, 590-603
作者:WARPEHOSKI, M. A.、GEBHARD, I.、KELLY, R. C.、KRUEGER, W. C.、LI, L. H.、MCGOV+