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.
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.
Cascade alkylarylation of substituted <i>N</i>-allylbenzamides for the construction of dihydroisoquinolin-1(2<i>H</i>)-ones and isoquinoline-1,3(2<i>H</i>,4<i>H</i>)-diones
作者:Ping Qian、Bingnan Du、Wei Jiao、Haibo Mei、Jianlin Han、Yi Pan
DOI:10.3762/bjoc.12.32
日期:——
An oxidative reaction for the synthesis of 4-alkyl-substituted dihydroisoquinolin-1(2H)-ones with N-allylbenzamide derivatives as starting materials has been developed. The radical alkylarylation reaction proceeds through a sequence of alkylation and intramolecular cyclization. The substituent on the C-C double bond was found to play a key role for the progress of the reaction to give the expected
An efficient and highly practical palladium-catalyzed arylperfluoroalkylation of unactivatedolefins is presented here. A variety of perfluoroalkylated heterocyclic derivatives can be obtained in high regioselectivity. The reaction proceeds mildly without the electronic activation of the aryl group and features high generality, low-cost fluoroalkylated sources and good functional-group compatibility
difunctionalization of N-allyl anilines toward the synthesis of silylated indolines using commercially available silanes has been reported. This strategy provides a new avenue for the synthesis of a diverse array of indolines in reasonable yields. Preliminary mechanistic investigations indicate that the reaction probably proceeds via a radical pathway with unactivatedalkenes as radical acceptors and simple silanes