Carbene-catalyzed reaction of carboxylic esters has the potential to offer effective synthetic solutions that cannot be readily achieved by using the more conventional aldehyde-type substrates. Here we report the first carbene-catalyzed dynamic kinetic resolution of α,α-disubstituted carboxylic esters with up to 99:1 er and 99% yield. The present study clearly illustrates the unique power of carbene-catalyzed reactions of readily available and easy to handle carboxylic esters.
A diverted total synthesis (DTS) approach to the total synthesis of pyridone alkaloids N-deoxymilitarinone A (8) and torrubiellone B (10) has been developed. The common intermediate 14 was first assembled by a dual directed orthometalation process using a methoxymethyl group as directed metalation group. Other crucial steps include the assembly of polyenes under aldol condensation for DTS using general and concise strategy and diastereoselective synthesis of the syn-dimethyl array by an Evans aldol reaction.
Synthesis of 3-fluoro-2-hetarylindoles through addition of hetarenes to 3,3-difluoroindolium ions generated in situ by Zn(OTf) 2 -catalyzed oxazolidine ring opening is described. Indoles, pyrroles and alkyl-substituted furans can be used as hetaryl nucleophiles to afford a range of 3-fluoro-2-hetarylindole products 6 in 56-95 % yields. A diverse array of 3,3-difluorinated 2-hetarylindolines 7 can also be synthesized in
A scalable procedure for the title transformation of a broad range of α,α‐disubstituted carboxylic esters is developed which delivers the products in often very high yields and with very high enantiomeric purity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.