879560-00-6Relevant articles and documents
Cascade and Effective Syntheses of Functionalized Tellurophenes
Karapala, Vamsi Krishna,Shih, Hong-Pin,Han, Chien-Chung
, p. 1550 - 1554 (2018/03/23)
A one-pot and transition-metal-catalyst-free synthetic strategy to construct functionalized tellurophenes has been developed. Substituted 1,1-dibromo-1-en-3-ynes are smoothly converted to tellurophenes with telluride salts in high yield via a series of cascade reactions through reductive debromination, hydrotelluration, nucleophilic cyclization, and aromatization. Close inspection of the results clearly showed that the reactivity of in situ prepared telluride salts are significantly influenced by the polarity of the solvent system and the electronic nature of the substituent on the enyne substrate. This method reports the first direct synthesis of 3-aryltellurophenes in high yields at room temperature. This novel reaction strategy is also found to be a promising synthetic method for multisubstituted tellurophenes and selenophenes.
Chiral propargyl alcohols via the enantioselective addition of terminal Di- and triynes to aldehydes
Graham, Erin R.,Tykwinski, Rik R.
, p. 6574 - 6583 (2011/10/05)
The enantioselective addition of di- and triynes to aldehydes is presented, including the first examples of an asymmetric triyne addition. Modification of the Carreira alkynylation protocol shows that addition of diynes and triynes to α-branched aldehydes can be complete in as little as 4 h, and these reactions give good yields and enantioselectivities (up to 98% ee) for di- and triynes tested (aryl, alkyl, and silyl). It is shown for two cases (20 and 24) that products of this asymmetric addition reaction can undergo further manipulation (desilylation and triazole formation) without affecting the enantiopurity.
