Gold-Catalyzed Enantioselective Ring-Expanding Cycloisomerization of Cyclopropylidene Bearing 1,5-Enynes
摘要:
An enantioselective ring-expanding cycloisomerization of 1,5-enynes bearing a cyclopropylidene moiety has been developed. This methodology provides a new approach to bicyclo[4.2.0]octanes, a structural motif present in many biologically active natural products.
Gold-Catalyzed Enantioselective Ring-Expanding Cycloisomerization of Cyclopropylidene Bearing 1,5-Enynes
摘要:
An enantioselective ring-expanding cycloisomerization of 1,5-enynes bearing a cyclopropylidene moiety has been developed. This methodology provides a new approach to bicyclo[4.2.0]octanes, a structural motif present in many biologically active natural products.
A novel K2CO3-mediated cyclization and rearrangement of γ,δ-alkynyl oximes for the synthesis of pyridols is described. The process accomplishes an efficient [1,3] rearrangement of the O-vinyl oxime intermediate which is in situ generated from the intramolecular nucleophilic addition of γ,δ-alkynyl oximes. The reaction employs readily accessible starting materials, tolerates a wide range of functional
描述了一种新颖的K 2 CO 3介导的γ,δ-炔基肟的环化和重排,用于合成吡咯。该方法完成了O-乙烯基肟中间体的有效[1,3]重排,该中间体是由γ,δ-炔基肟的分子内亲核加成反应原位产生的。该反应采用容易获得的起始原料,耐受各种官能团,并以高收率得到各种合成上具有挑战性的吡咯。
Silver-Promoted Oxidative Ring Opening/Alkynylation of Cyclopropanols: Facile Synthesis of 4-Yn-1-ones
作者:Ye-Xiang Xie、Jin-Heng Li、Cheng-Yong Wang、Ren-Jie Song
DOI:10.1055/s-0035-1560374
日期:——
silver-promoted oxidative ringopening/alkynylation of cyclopropanols with ethynylbenziodoxolones (EBX) is described. This method enables the formation of alkylated alkynes via a sequence of ringopening and alkynylation. Control experiments support a radical mechanism in this silver-promoted method. A new silver-promoted oxidative ringopening/alkynylation of cyclopropanols with ethynylbenziodoxolones