第二代Grubbs钌催化剂与乙烯基氧基三甲基硅烷的反应可有效生成具有N-杂环卡宾(NHC)配体的纯氢化钌络合物,并具有明确的特征。该氢化钌络合物对末端烯烃的选择性异构化和1,6-二烯的环异构化显示出高催化活性。的这些反应Ñ -allyl- Ò -vinylaniline导致新的合成方法杂环如吲哚和3-亚甲基-2,3- dihydroindoles,这对于生物活性天然产物有用的合成子。这些程序解决了面向多样性的综合中的一个重要问题。
The Pt-catalyzed hydrosilylation of equilibrating allylic azides is reported. The reaction provides only one out of four possible hydrosilylation products in good yields and with very high chemoselectivity (alk-1-ene vs. alk-2-ene), regioselectivity (linear vs. branched), and excellent functional group tolerance.
Synthesis of <i>gem</i>-Difluoromethylenated Bicyclo[<i>m.n.</i>0]alkan-1-ols and Their Ring-Expansion to <i>gem</i>-Difluoromethylenated Macrocyclic Lactones
adduct afforded the corresponding gem-difluoromethylenated bicyclic compounds 4, which underwent ring-expansion followed by the Baeyer–Villiger-type oxidation of the resulting macrocyclic ketone intermediates to give gem-difluoromethylenated macrocycliclactones 5.
Ring Closing Metathesis/Fragmentation Route to (<i>Z</i>)-Configured Medium Ring Cycloalkenes. Total Synthesis of (±)-Periplanone C
作者:Radomir Matovic、Aleksandar Ivkovic、Marija Manojlovic、Zorana Tokic-Vujosevic、Radomir N. Saicic
DOI:10.1021/jo061790j
日期:2006.12.1
The combination of ring closing metathesis and β-fragmentation offers an efficient entry into (Z)-configured mediumringcycloalkenes. The fragmentation step can be effected under anionic or radical conditions. The versatility of this method is demonstrated by the total synthesis of (±)-periplanone Ca macrocyclic pheromone of Periplaneta americana.
C–C bond through a radical process is described. The sequence comprises an initial in situ generation of a putative iron hydride followed by a hydrogenatomtransfer to an alkene, a coupling with a hydrazone, and a final reduction of the nitrogen-centered radical. Hydrogenation of the obtained hydrazines renders amines, including valuable tert-alkyl amines.