Highly stereoselective synthesis of β,γ-disubstituted and α,β,γ-trisubstituted butyrolactones
摘要:
beta,gamma-Disubstituted butyrolactones were produced effectively and steroeselectively from arsonium ylides generated in situ and substituted olefins. The transformation could be realized in one-pot or in two steps, which depended on the electronic properties of the olefins. With the adjustment of the solvent and in the presence of EtOH, alpha,beta,gamma-trisubstituted butyrolactones were also obtained in high yield from arsonium ylides and substituted olefins. (C) 2008 Elsevier Ltd. All rights reserved.
A highlystereoselectivesynthesis of exo-spiro[cyclopropane-1,4′-pyrazolin-5′-one] from 4-arylidene-3-methyl-1-phenyl-pyrazolin-5-one and arsonium bromide in the presence of base has been achieved. The triphenylarsine-catalyzed cyclopropanation of 4-arylidene-3-methyl-1-phenyl-pyrazolin-5-one with bromide in the presence of NaHCO3 has also been studied. Both exo and endo isomers were formed in this
在碱存在下,由4-亚芳基-3-甲基-1-苯基-吡唑啉-5-酮和溴化砷高度立体选择性地合成exo -spiro [cyclopropane-1,4'-pyrazolin-5'-one]实现了。在NaHCO 3存在下,还研究了三苯ar催化四溴化亚芳基-3-甲基-1-苯基-1-吡唑啉-5-酮的环丙烷化反应。两个外和内切形成在该反应中的异构体。产物的结构通过IR,MS,1 H NMR,元素分析和X射线衍射分析来表征。
Highly stereoselective synthesis of cyclopropyl heterocycles<i>via</i>cyclopropanation of olefin with arsonium salt
作者:Zhongjiao Ren、Weiguo Cao、Weiqi Tong、Jie Chen、Changqing Wang
DOI:10.1002/jhet.5570450105
日期:2008.1
An efficient and highlystereoselective approach for the preparation of highly functionalized cyclopropyl heterocycles via the cyclopropanation of olefines with arsonium salts in the presence of KF2H2O has been developed.
Abstract A facile and highly stereoselective methodology for the preparation of highly functionalized trans-1,2-cyclopropanes containing benzoimidazolyl, cyano, aryl, and carbonyl groups 3 is described. Arsonium bromides 2 reacted with electron-deficient olefins 1 in the presence of KF·2H2O to provide 3 exclusively with high stereoselectivity in moderate to good yields.
A facile preparation of trans-1,2-cyclopropanes containing p-trifluoromethylphenyl group and its application to the construction of pyrazole and cyclopropane ring fused pyridazinone derivatives
A facile methodology for the preparation of highly functionalized trans-1,2-cyclopropanes containing p-trifluoromethylphenyl group 3 is described. Arsonium bromides 1 reacted with electron-deficient olefins 2 in the presence of K2CO3 to provide 3 stereoselectively in moderate to good yields. This process has been successfully applied to the construction of cyclopropane ring fused pyridazinone derivatives
描述了一种用于制备含有对-三氟甲基苯基3的高度官能化的反式-1,2-环丙烷的简便方法。鉮溴化物1与缺电子烯烃反应2中K的存在2 CO 3,以提供3在中度至良好的产率立体选择性。该方法已成功地应用于环丙烷环稠合的哒嗪酮衍生物4或吡唑衍生物5的构建。
Stereoselective synthesis of highly substituted trans-2,3-dihydrofuran and trans-1,2-cyclopropane derivatives containing sulfonyl groups
作者:Weiguo Cao、Hui Zhang、Jie Chen、Xiaohong Zhou、Min Shao、Mark C. McMills
DOI:10.1016/j.tet.2007.10.073
日期:2008.1
trans-2,3-Dihydrofuran derivatives 3 and trans-1,2-cyclopropane derivatives 4 were prepared with high chemoselectivity and moderate overall chemical yield by the reaction of alpha,beta-unsaturated sulfones 1 with arsonium bromides 2 in the presence of potassium carbonate. The structures of products obtained were identified by IR, MS, (1)H NMR, elemental analysis, and X-ray diffraction analysis. (c) 2007 Elsevier Ltd. All rights reserved.