Catalytic opening of the diaziridine fragment in 6-aryl-1,5-diazabicyclo[3.1.0]hexanes
摘要:
Treatment of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes with Lewis acids [(BF3Et2O)-Et-. or In(OTf)(3)] promotes opening of the diaziridine ring, followed by formation of 1,3-dipolar cycloaddition products with N-arylmaleimides. The conversion of the initial diaziridine depends on the nature of the 6-aryl group. Diazabicyclohexanes with donor substituents react quantitatively to give (in the absence of dipolarophiles) the corresponding azomethine imine dimers, 1,2,4,5-tetrazine derivatives. The conversion of diazabicyclohexanes having acceptor substituents is poor; simultaneously, the fraction of the hydrolysis products increases. The stereoselectivity in the 1,3-dipolar cycloaddition, i.e. the ratio of the cis- and trans-adducts, depends on the catalyst and solvent. Azomethine imine dimers react with N-arylmaleimides in the presence of indium(111) trifluoromethanesulfonate to give the same 1,3-dipolar cycloaddition products as those obtained from parent 1,5-diazabicyclohexanes.
在热解条件下,由6-芳基-1,5-二氮杂双环[3.1.0]己烷1生成的偶氮甲亚胺与二甲环亚胺形成的二倍过量的二苯基环丙烯酮的正式[2 + 3]环加成反应可能是通过最初形成的不稳定的偶极双环中间体4发生的。这些中间体的异构化以及随后的第二分子二苯基环丙烯酮的加入以及一分子一氧化碳的挤出导致以良好的产率形成三环的4a,7b-二氮杂环戊[ cd ]茚满7-酮8。
Thermally Induced Tandem Cycloaddition of 2-Alkyl-3-phenylcyclopropenones to 6-Aryl-1,5-diazabicyclo[3.1.0]hexanes
作者:A. P. Molchanov、D. I. Sipkin、Yu. B. Koptelov、R. R. Kostikov
DOI:10.1007/s11178-005-0205-z
日期:2005.4
Thermolysis of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes in the presence of 2-alkyl-3-phenylcyclopropenones gives fused polycyclic systems of the 4a,7b-diazacyclopenta[cd]inden-7-one series as a result of addition of two cyclopropenone molecules and extrusion of CO molecule. The first step of the process is characterized by 100% regioselectivity, leading to the adduct with vicinal arrangement of the aryl groups, while the regioselectivity of the second step is likely to be determined by spatial interactions between substituents in the cyclopropenone molecule and trimethylene bridge of the diazabicyclohexane. Steric hindrances in the second step could eliminate formation of stable products.
6- 芳基-1,5-二氮杂双环[3.1.0]己烷在 2-烷基-3-苯基环丙烯酮存在下发生热解,产生 4a,7b-二氮杂环戊并[cd]茚-7-酮系列的融合多环体系,这是两个环丙烯酮分子相加和 CO 分子挤出的结果。该过程第一步的特点是具有 100% 的区域选择性,可产生芳基邻接排列的加合物,而第二步的区域选择性可能取决于环丙烯酮分子中的取代基和二氮杂双环己烷的三亚甲基桥之间的空间相互作用。第二步中的立体阻碍可能会导致无法形成稳定的产物。
Regioselectivity in the Addition of 1,3-Dipolarophiles to 6-Aryl-1,5-diazabicyclo[3.1.0]hexanes
作者:A. P. Molchanov、D. I. Sipkin、Yu. B. Koptelov、J. Kopf、R. R. Kostikov
DOI:10.1023/b:rujo.0000034912.48684.d4
日期:2004.1
Thermolysis of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes in the presence of 1,3-dipolarophiles having an unsymmetrically substituted double Cdouble bondC bond (such as N-arylimides derived from 2-aryl-substituted maleic, citraconic, and itaconic acids, ethyl propynoate, aryl isocyanates, and aryl isothiocyanates) leads to formation of the corresponding 1,3-dipolar cycloaddition products. The reaction is regioselective, and in most cases only one regioisomer is obtained. The addition direction depends on the 1,3-dipolarophile structure, i.e., electronic and steric factors determining the most effective orbital interaction upon approach of the reagent to substrate.
Double Addition of Diphenylcyclopropenone to Azomethine Imines Generated from 6-Aryl-1,5-diazabicyclo[3.1.0]hexanes
作者:Alexander P. Molchanov、Denis I. Sipkin、Yuri B. Koptelov、Rafael R. Kostikov
thermolysis conditions presumably occurs via the initially formed unstable dipolar bicyclic intermediates 4. Isomerization of these intermediates and subsequent addition of the second molecule of diphenylcyclopropenone with the extrusion of one molecule of carbon monoxide results in the formation of tricyclic 4a,7b-diazacyclopenta[cd]inden-7-ones 8 in good yields.
在热解条件下,由6-芳基-1,5-二氮杂双环[3.1.0]己烷1生成的偶氮甲亚胺与二甲环亚胺形成的二倍过量的二苯基环丙烯酮的正式[2 + 3]环加成反应可能是通过最初形成的不稳定的偶极双环中间体4发生的。这些中间体的异构化以及随后的第二分子二苯基环丙烯酮的加入以及一分子一氧化碳的挤出导致以良好的产率形成三环的4a,7b-二氮杂环戊[ cd ]茚满7-酮8。
Catalytic opening of the diaziridine fragment in 6-aryl-1,5-diazabicyclo[3.1.0]hexanes
作者:Yu. B. Koptelov
DOI:10.1134/s1070428006100204
日期:2006.10
Treatment of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes with Lewis acids [(BF3Et2O)-Et-. or In(OTf)(3)] promotes opening of the diaziridine ring, followed by formation of 1,3-dipolar cycloaddition products with N-arylmaleimides. The conversion of the initial diaziridine depends on the nature of the 6-aryl group. Diazabicyclohexanes with donor substituents react quantitatively to give (in the absence of dipolarophiles) the corresponding azomethine imine dimers, 1,2,4,5-tetrazine derivatives. The conversion of diazabicyclohexanes having acceptor substituents is poor; simultaneously, the fraction of the hydrolysis products increases. The stereoselectivity in the 1,3-dipolar cycloaddition, i.e. the ratio of the cis- and trans-adducts, depends on the catalyst and solvent. Azomethine imine dimers react with N-arylmaleimides in the presence of indium(111) trifluoromethanesulfonate to give the same 1,3-dipolar cycloaddition products as those obtained from parent 1,5-diazabicyclohexanes.