Rh-Catalyzed Transannulation of <i>N</i>-Tosyl-1,2,3-Triazoles with Terminal Alkynes
作者:Buddhadeb Chattopadhyay、Vladimir Gevorgyan
DOI:10.1021/ol2014347
日期:2011.7.15
The first transannulation of 1,2,3-triazoles with terminal alkynes into pyrroles is reported. The reaction proceeds in the presence of a Rh2(oct)4/AgOCOCF3 binary catalyst system providing a straightforward approach to 1,2,4-trisubstituted pyrroles in good to excellent yields.
base‐promoted nucleophilic addition of arylacetonitriles to terminal alkynes has been described for the first time, providing a simple and straightforward protocol for the synthesis of a range of structurally diverse (Z)‐2,3‐disubstituted acrylonitriles in moderate to excellent yields. Of particular note, the transition metal‐free carbon‐carbon double bond forming reaction is regio‐ and stereoselective under
addition/cyclization/halogen atomtransferbetween alkynes and α-halogeno-γ, δ-unsaturated carbonyl compounds for the synthesis of various substituted cyclopentenes is described. Since up to four Csp3–Csp2 bonds, two Csp3–Br bonds, and two carbocycles can be established in a single reaction, this 100% atom-efficient reaction exhibits the advantages of wide substrate scope, high functional group tolerance, and step-economics
In this protocol, the chemoselective defluoromethoxylation reactions of 2-trifluoromethyl-1,3-enynes were developed. The enynic and allenic orthoesters were selectively produced in good to excellent yields via multiple substitution processes under mild reaction conditions, respectively. The enynic orthoester products were proved capable of acting as efficient “platform molecules” to access various
Treatment of 2-(1-aryl-3-propynoyl) anisoles 1 with N-chlorosuccinimide (NCS) or N-bromosuccinimide (NBS) gave the 3-halogenated flavones and their related molecules in moderate yields.