PHOTOINDUCED TRANSFORMATION OF CARBONYL COMPOUNDS UTILIZING SELECTIVE INTERACTION WITH AMINES

在这项研究中，我们首先研究了羰基化合物和胺的光反应产生的离子自由基对的相互作用的性质。然后我们重点研究了几种底物的还原转化和新的电子给体化合物的合成。通过这些努力，获得了几个有趣的观察结果，如下所述。例如，溴甲基取代苯环酮与各种胺的光反应表明，这些化合物衍生的自由基中间体的反应过程的选择性显著地受所涉及的胺阳离子自由基的性质的影响。特别是，这些羰基化合物与1，3-二甲基-2-苯基苯并咪唑(DMPBI)的光反应是值得注意的。从这些底物衍生的中间碳自由基可以从DMPBI阳离子自由基中提取氢原子来提供观察到的产物。另一方面，DMPBI…可以还原相同的碳自由基更多的自由基是由DMPBI阳离子自由基通过加碱去质子化生成的，通过质子化得到相同产物的碳负离子。为了开发利用DMPBI及其衍生物进行高效和选择性的光转化，我们用DMPBI和醋酸的组合进行了环氧酮的光还原，以较高的产率合成了所需的羟基酮。在该反应中，首次成功地分离了氧化的DMPBI，1，3-二甲基-2-苯基苯并咪唑盐。合成了2-萘基和2-苯基取代的1，3-二甲基苯并咪唑类化合物，并发现它们对某些羰基化合物有较好的光诱导还原作用。为了寻找适用于上述光化学体系的新底物，还对几种羰基化合物进行了二碘化钐的还原反应。随后，发现了前所未有的酮基分子内亲核反应性。我们希望我们在这一领域和相关领域的持续研究将使我们能够开发出使用DMPBI及其类似物的新的光诱导电子转移反应体系。较少

In this research, we first investigated the nature ot the interaction of the ion radical pairs generated by photoreaction of carbonyl compounds and amines. We then paid our attention to the reductive transformation ot several substrates and the synthesis of new electron donor compounds. Through these efforts, several interesting observations were obtained as described below. For example, photoreaction of bromomethyl substituted benzocyclic ketones and various amines revealed that the selectivity of the reaction course for the radical intermediates derived from these compounds was significantly influenced by the nature of the amine cation radicals involved. Particularly, photoreaction of these carbonyl compounds with 1,3-dimethyl-2-phenylbenzimidazoline (DMPBI) was noteworthy. The Intermediate carbon radicals derived from these substrates could abstract hydrogen atom from DMPBI cation radical to afford observed products. On the other hand, same carbon radicals could be reduced by DMPBI … More radical generated from the deprotonation of DMPBI cation radical by added bases to become the carbanions giving same products through protonation. In the connection with our purpose of the development of highly efficient and selective phtotransformation using DMPBI and its derivatives, we conducted photo-reduction of epoxy ketones with the combination of DMPBI and acetic acid to produce desired hydroxy ketones in good yields. In this reaction, isolation of the oxidized DMPBI, 1,3-dimethyl-2-phenylbenzimidazolium salt was first succeeded. 2-Naphthyl and 2-anthryl substituted 1,3-dimethylbenziimidazolines were synthesized and were found to be effective for the photoinduced reduction of some carbonyl compounds. In order to find new substrates which could be applicable to the above phtochemical systems, samarium diiodide reduction of several carbonyl compounds were also conducted. Then, unprecedented intramolecular nucleophilic reactivity of ketyl radicals was discovered. We hope that our continuous investigation in this and the related areas will allow us to develop new photoinduced electron transfer reaction systems using DMPBI and its analogues. Less