ring-contracted imidazolonequinoxalines with increased triplet energy (ET) and H-atom abstraction (HAT) strength in the photochemically excitedstate. Ring-contracted flavins are efficient catalysts in the trifluoromethylthiolation of aliphatic C−H positions and also in multi-step sequences, which require the combined activity as triplet sensitizer and hydrogen atom abstractor.
酯改性黄素与氢氧化物碱的反应产生环收缩的咪唑啉酮喹喔啉,其在光化学激发态下具有增加的三线态能量( ET )和氢原子夺取(HAT)强度。缩环黄素是脂肪族 C-H 位三氟甲硫基化反应以及多步骤序列中的有效催化剂,这需要三重态敏化剂和氢原子抽象剂的组合活性。
Synthetic Photochemistry. XIII. Chiroptical Retention for the Reported “<i>antara-antara</i>”-3,3-Sigmatropy of Bicyclo[3.2.0]hepta-3,6-dien-2-ones
Troponoids were shown to form 2:1-complexes with β-cyclodextrin and 1:1-complexes with α-cyclodextrin. The photoisomerization of complexed tropolone and 2-methoxytropone gave optically active 1-hydroxy- and 1-methoxybicyclo[3.2.0]hepta-3,6-dien-2-ones in improved yields. The pyrolysis of the (+)-1-methoxybicyclo[3.2.0]hepta-3,6-dien-2-one gave the (+)-3-methoxybicyclo[3.2.0]hepta-3,6-dien-2-one, ruling