Structure-activity relationships among di- and tetramine disulfides related to benextramine
摘要:
The synthesis and irreversible alpha-blocking activity in the rat vas deferens of a series of tetra- and diamine disulfides 2-38, structural analogues of benextramine (BHC), are described. All compounds containing a central cystamine moiety displayed an irreversible alpha-adrenergic blockade at concentrations ranging from 10(-4) to 6 X 10(-6)M. Potency was increased in cystamines N,N'-disubstituted with 6-aminohexyl groups, especially when the outer nitrogen atoms bear arylalkyl substituents or are enclosed in a ring. However, N,N,N',N'-tetrasubstituted cystamines were poor blockers. Structural specificity in the outer portion of the tetramine disulfide is low, since many types of substituents gave rise to potent alpha-blockers. Even replacement of the outer amines with nonbasic ethers or amides was observed to maintain irreversible alpha-blockade.
Nickel/Cobalt-Catalyzed C(sp<sup>3</sup>)–C(sp<sup>3</sup>) Cross-Coupling of Alkyl Halides with Alkyl Tosylates
作者:Kimihiro Komeyama、Takuya Michiyuki、Itaru Osaka
DOI:10.1021/acscatal.9b03352
日期:2019.10.4
The C(sp3)–C(sp3) cross-coupling of alkyl halides with alkyl tosylates has been developed by employing a combination of nickel and nucleophilic cobalt catalysts in the presence of a manganese reductant. This method provides a straightforward route to a diverse set of not only secondary–primary but also primary–primary C(sp3)–C(sp3) linkages under mild conditions without using alkyl-metallic reagents