N-(甲氧基丙-2-基)苯甲腈(1)的酸水解动力学研究是在75.1°C的8.84 M HCl和/或DCl中进行的。对2-(N-苯基氨基)丙醇(4)的形成进行了解释,并阐明了由酰胺基团辅助通过胺基异构体进行的初始醚裂解的机理。整个过程通过涉及两个中间体的三个步骤发展。各个过程的速率常数已通过UV和1 H NMR光谱技术确定。
Functional group manipulation via organoselenium- and halogen-induced cyclofunctionalization/hydrolysis of allylic benzimidates, tertiary benzamides, and benzamidines. Regioflexible synthesis of amino alcohol derivatives
摘要:
Allylic benzimidates were treated with benzeneselenenyl halides in chloroform or acetonitrile to give, via 5-exo cyclofunctionalization/hydrolysis, 3-(benzoyloxy)-2-(phenylamino)-1-(phenylselenenyl)-alkanes in fair yields. Allylic tertiary benzamides afforded 2-(benzoyloxy)-3-(phenylamino)-1-(phenylselenenyl)alkanes when submitted to similar reaction conditions. Bromoalkanes, functionalized in an analogous way, were obtained after hydrolytic workup when bromine was added to allylic benzimidates and tertiary benzamides. In some of these reactions, products of 6-endo cyclofunctionalization/hydrolysis (1-(benzoyloxy)-3-(phenylamino)-2-bromoalkanes) were also formed. The addition of benzeneselenenyl bromide to some a-substituted allylic benzimidates and tertiary benzamides was diastereoselective (0 < de < 90%, depending on conditions) with a preference for threo isomer formation. Hydrodeselenation/hydrodebromination of the cyclofunctionalization/hydrolysis products was efficiently effected (88-100% yield) by treatment of the products with triphenyltin hydride in refluxing benzene containing a catalytic amount of azobis(isobutyronitrile). The proper choice of allylic benzimidate/tertiary benzamide allowed the preparation of amino alcohol derivatives in which the 1,2-orientation of the functional groups, relative to the carbon backbone, could be varied in a controlled and predictable manner. The regioflexibility of the process was demonstrated for primary, secondary, and tertiary positions. When allylic benzamidines were submitted to the cyclofunctionalization/hydrolysis reaction conditions using benzeneselenenyl bromide as the electrophilic reagent, 5-phenylselenenyl(methyl) -substituted dihydroimidazoles were obtained.
Anomalous addition of tellurium tetrachloride to allylic esters. Short synthesis of trans-(2S,3S)-2,3-epoxybutane
作者:Lars Engman
DOI:10.1021/ja00326a015
日期:1984.7
Mecanisme et stereochimie de la reaction conduisant aux esters de chloromethyl-1 trichlorotelluranyl-2 ethyle. Application a la synthese de l'epoxyde du titre a partir du benzoate de methyl-1allyle
Mecanisme et stereochimie de la reaction conduisant auxesters de chloromethyl-1 trichlorotelluranyl-2ethyle。应用 a la 合成 de l'epoxyde du titre a partir du benzoate demethyl-1allyle
ENGMAN, L., J. AMER. CHEM. SOC., 1984, 106, N 14, 3977-3984
作者:ENGMAN, L.
DOI:——
日期:——
Functional group manipulation via organoselenium- and halogen-induced cyclofunctionalization/hydrolysis of allylic benzimidates, tertiary benzamides, and benzamidines. Regioflexible synthesis of amino alcohol derivatives
作者:Lars Engman
DOI:10.1021/jo00061a009
日期:1993.4
Allylic benzimidates were treated with benzeneselenenyl halides in chloroform or acetonitrile to give, via 5-exo cyclofunctionalization/hydrolysis, 3-(benzoyloxy)-2-(phenylamino)-1-(phenylselenenyl)-alkanes in fair yields. Allylic tertiary benzamides afforded 2-(benzoyloxy)-3-(phenylamino)-1-(phenylselenenyl)alkanes when submitted to similar reaction conditions. Bromoalkanes, functionalized in an analogous way, were obtained after hydrolytic workup when bromine was added to allylic benzimidates and tertiary benzamides. In some of these reactions, products of 6-endo cyclofunctionalization/hydrolysis (1-(benzoyloxy)-3-(phenylamino)-2-bromoalkanes) were also formed. The addition of benzeneselenenyl bromide to some a-substituted allylic benzimidates and tertiary benzamides was diastereoselective (0 < de < 90%, depending on conditions) with a preference for threo isomer formation. Hydrodeselenation/hydrodebromination of the cyclofunctionalization/hydrolysis products was efficiently effected (88-100% yield) by treatment of the products with triphenyltin hydride in refluxing benzene containing a catalytic amount of azobis(isobutyronitrile). The proper choice of allylic benzimidate/tertiary benzamide allowed the preparation of amino alcohol derivatives in which the 1,2-orientation of the functional groups, relative to the carbon backbone, could be varied in a controlled and predictable manner. The regioflexibility of the process was demonstrated for primary, secondary, and tertiary positions. When allylic benzamidines were submitted to the cyclofunctionalization/hydrolysis reaction conditions using benzeneselenenyl bromide as the electrophilic reagent, 5-phenylselenenyl(methyl) -substituted dihydroimidazoles were obtained.
Mechanistic investigation of an anomalous anchimeric assistance in the acid hydrolysis of the ether linkage. Part 4
Kinetic investigation of the acidhydrolysis of N-(methoxyprop-2-yl)benzanilide (1) was performed in 8.84 M HCl and/or DCl at 75.1°C. The formation of 2-(N-phenylamino)propanol (4) was explained and the mechanism, involving an initial ether cleavage anchimerically assisted by the amide group, was clarified. The overall process evolves through three steps involving two intermediates. The rate constants
N-(甲氧基丙-2-基)苯甲腈(1)的酸水解动力学研究是在75.1°C的8.84 M HCl和/或DCl中进行的。对2-(N-苯基氨基)丙醇(4)的形成进行了解释,并阐明了由酰胺基团辅助通过胺基异构体进行的初始醚裂解的机理。整个过程通过涉及两个中间体的三个步骤发展。各个过程的速率常数已通过UV和1 H NMR光谱技术确定。