Synthesis of a highly reactive 1,1-dicyanomethylene-1-dethiacephalosporin
摘要:
Synthesis of the 1,1-dicyanomethylene-1-dethiacephalosporin 1a is described. Substitution of the dicyanomethylene moiety for sulfur at position 1 of the cephem nucleus resulted in a highly reactive beta-lactam antibacterial.
A catalyticapproach to the titanocene-mediated radical cyclization of epoxy nitriles and epoxy carbonyl compounds to hydroxy ketones and diols is described. The reaction is sensitive to the substitution pattern of the catalyst and especially useful for the preparation of cyclobutanones. It can also be used for nitrile grouptransfer.
Enantioselective Synthesis of Vicinal All‐Carbon Quaternary Centers via Iridium‐Catalyzed Allylic Alkylation
作者:J. Caleb Hethcox、Samantha E. Shockley、Brian M. Stoltz
DOI:10.1002/anie.201804820
日期:2018.7.9
development of the first enantioselective transition‐metal‐catalyzedallylicalkylation providing access to acyclic products bearing vicinal all‐carbonquaternarycenters is disclosed. The iridium‐catalyzedallylicalkylation reaction proceeds with excellent yields and selectivities for a range of malononitrile‐derived nucleophiles and trisubstituted allylic electrophiles. The utility of these sterically congested