Umpolung of Michael Acceptors Catalyzed by <i>N</i>-Heterocyclic Carbenes
作者:Christian Fischer、Sean W. Smith、David A. Powell、Gregory C. Fu
DOI:10.1021/ja058222q
日期:2006.2.1
N-Heterocycliccarbenes can catalyze beta-alkylations of a range of alpha,beta-unsaturated esters, amides, and nitriles that bear pendant leaving groups to form a variety of ring sizes. In this process, the nucleophilic catalyst transiently transforms the normally electrophilic beta carbon into a nucleophilic site through an unanticipated addition-tautomerization sequence.
Domino 1,4- and 1,6-Addition Reactions of Ketene Silyl Acetals to Dialkynyl Imines Promoted by Aluminum Chloride: Synthesis of Multifunctionalized β-Lactams
Domino 1,4- and 1,6-addition reactions of ketenesilylacetals to dialkynyl imines are disclosed. Aluminum chloride promoted domino 1,4- and 1,6-addition reactions of ketenesilylacetals to dialkynyl imines to give a variety of alkenyl iminocyclobutenones in moderate to good yields. The chemoselective reduction of alkenyl iminocyclobutenones and the subsequent thermal rearrangement of resulting alkenyl
4,5-bis(aryl) 4H-1,2,4-triazoles derivatives and analgesic use
申请人:Roussel Uclaf
公开号:US05278180A1
公开(公告)日:1994-01-11
A novel process for the preparation of 4H-1,2,4-triazoles in their racemic or optically active forms of the formula ##STR1## wherein the compounds have analgesic activity.
Transformation of Amides to Thioamides Using an Efficient and Novel Thiating Reagent
作者:Mohamed S. Gomaa、Gaber El Enany、Walid Fathalla、Ibrahim A. I. Ali、Samir. M. El Rayes
DOI:10.3390/molecules27238275
日期:——
convenient protocol was developed for the transformation of N-aryl-substituted benzamides to N-aryl-substituted benzothioamides using N-isopropyldithiocarbamate isopropyl ammonium salt as a novel thiating reagent. The major advantages of this protocol are its one-pot procedure, short reaction times, mild conditions, simple work-up, high yields and pure products.