Synthesis and Reactivity of α- and β-Chloro-α-phenylselanyl Esters
摘要:
Thermal decomposition of the dichloro-adducts derived from alpha-phenylselanylesters 1, 2 and 4 has been studied. N-Chloro-succinimide treatment of esters 2 was an efficient preparative method for alpha-chloro-alpha-phenylselanylesters 10 and alpha-chloro-alpha,beta-unsaturated esters 11. Some transformations of esters 10 were achieved. alpha,beta-Dichloro-alpha-phenylselanylesters 22 were prepared from beta-chloro-alpha-phenyl selanylesters 5 or by decomposition of the dichloroselenuranes 21 derived from esters 4. (C) 2000 Elsevier Science Ltd. All rights reserved.
and selenenylation of selenium-stabilized ester enolates have allowed the preparation of α-phenylselanyl esters 5, 7, 8 and of α,α-bis(phenylselanyl)esters 6, respectively. The competitive selenophilic reaction, leading to an allylic phenylselenide 9, was avoided in the presence of HMPA. α-phenylselanyl α,β-unsaturated esters 15 were prepared by oxidation of compounds 6 and dehydrohalogenation of β-chloroesters
烷基化和硒稳定酯烯醇化物的selenenylation已经允许α-phenylselanyl酯的制备5,7,8 α的和,α -双(phenylselanyl)酯6分别。在HMPA存在下,避免了竞争性的亲脂性反应,导致烯丙基苯基硒化物9。通过化合物6的氧化和β-氯代酯17的脱卤化氢制备α-苯基硒基α,β-不饱和酯15。还研究了其他一些转化:氧化,酯交换和格氏反应。Z酯的H 2 O 2氧化15导致产生稳定的E -α-硒烯酸酯20。
ALEXANDER, R. P.;PATERSON, I., TETRAHEDRON LETT., 1983, 24, N 52, 5911-5914