N-(1H)-Tetrazole sulfoximines are readily available by addition of sodium azide to the corresponding N- cyano derivatives in the presence of ZnBr2. The use of these N-(1H)-tetrazoles as intermediates in the synthesis of other N-heterocyclic sulfoximines is demonstrated.
Access to N-cyanosulfoximines by transition metal-free iminations of sulfoxides
作者:C. A. Dannenberg、L. Fritze、F. Krauskopf、C. Bolm
DOI:10.1039/c6ob02691e
日期:——
transition metal-free synthesis of N-cyanosulfoximines from sulfoxides using N-chlorosuccinimide (NCS) as oxidising agent and cyanamide as nucleophilic amine source is reported. The products are obtained in moderate to excellent yields. The protocol enables an easy access to N-cyanosulfoximines from readily available starting materials under inversion of configuration at a preexisting stereogenic center.
At elevated temperatures, N-cyanosulfoximines react with Meldrum’s acidderivatives to give sulfoximines with N-bound 5-carbonyl-1,3-oxazine-2,4-dione groups. A representative product was characterized by single-crystal X-ray structure analysis. The product formation involves an unexpected molecular reorientation requiring several sequential bond-forming and -cleaving processes.
Iodinane- and Metal-Free Synthesis of <i>N</i>-Cyano Sulfilimines: Novel and Easy Access of <i>N</i>H-Sulfoximines
作者:Olga García Mancheño、Olivia Bistri、Carsten Bolm
DOI:10.1021/ol7016577
日期:2007.9.1
The synthesis of N-cyanosulfilimines can readily be achieved by reaction of the corresponding sulfides with cyanogen amine in the presence of a base and NBS or I-2 as halogenating agents. Oxidation followed by C-N bond cleavage affords synthetically useful NH-free sulfoximines.