method for the synthesis of 4-chalcogenylated pyrazoles has been developed via electrophilic chalcogenation/cyclization of α,β-alkynic hydrazones. The cyclization of α,β-alkynic aldehyde hydrazones could be induced by using either sulfenyl chloride or the S-electrophiles generated in situ from the reaction of NCS and arythiol. The developed method was successfully applied to the synthesis of the sulfenyl
Preparative and Mechanistic Studies toward the Rational Development of Catalytic, Enantioselective Selenoetherification Reactions
作者:Scott E. Denmark、Dipannita Kalyani、William R. Collins
DOI:10.1021/ja106837b
日期:2010.11.10
attached to the selenium atom significantly attenuates the racemization of seleniranium ions. A variety of achiral Lewis bases catalyze the intramolecular selenoetherification of alkenes using N-(2-nitrophenylselenenyl)succinimide as the electrophile along with a Brønstedacid. Preliminary mechanistic studies suggest the intermediacy of ionic Lewis base-selenium(II) adducts. Most importantly, a broad
Ring‐Opening 1,3‐Aminochalcogenation of Donor–Acceptor Cyclopropanes: A Three‐Component Approach
作者:André U. Augustin、Peter G. Jones、Daniel B. Werz
DOI:10.1002/chem.201902160
日期:2019.9.6
A 1,3‐aminothiolation was realized by reacting 2‐substituted cyclopropane 1,1‐dicarboxylates with sulfonamides and N‐(arylthio)succinimides. Under Sn(OTf)2 catalysis the transformation proceeded smoothly to the corresponding ring‐opened products bearing the sulfonamide in the 1‐position next to the donor and the arylthio residue in the 3‐position next to the acceptor. The procedure was extended to
Acid-Mediated Oxychalcogenation of <i>o</i>-Vinylanilides with <i>N</i>-(Arylthio/arylseleno)succinimides
作者:Manthena Chaitanya、Pazhamalai Anbarasan
DOI:10.1021/acs.orglett.8b00065
日期:2018.2.16
An efficient acid-mediated oxythiolation of o-vinylanilides has been accomplished, employing N-(arylthio)succinimide as an electrophilic arylthiolating reagent for the synthesis of various arylthio tethered benzoxazine derivatives in good to excellent yield. The important features of this method include wide functional group tolerance, quick reaction time, absence of metal or additive, and excellent
A Convenient Solid-Phase Synthesis of Coumarins by TMSOTf-Catalyzed Intramolecular Seleno-Arylation of Tethered Alkenes
作者:E. Tang、Wen Li、Zhangyong Gao
DOI:10.1055/s-0031-1290618
日期:2012.4
performed using polystyrene-supported succinimidyl selenide as the selenium source. This catalytic process provides an efficient method for the regioselectivesynthesis of dihydrocoumarins possessing a seleno functionality, followed by syn elimination of selenoxides to provide coumarins in good yields and purities. Suzuki cross-coupling reaction of the resin-bound bromodihydrocoumarin was also performed