Metal-Free Access to Fully Substituted Skipped Diynes. An Efficient Chemodifferentiating A2BB‘ 4CR Manifold
摘要:
A metal-free chemodifferentiating A(2)BB' 4CR manifold for the modular synthesis of tertiary skipped diynes is described. The manifold performs a triethylamine triggered reaction of alkyl propiolates and acid chlorides to assemble two units of each component in the form of two propargylic alkynoates, a tertiary alcohol, and an ester. A differentiated incorporation of the two acid chloride components ensures functional diversity in the final structure. In addition, the presence of two connected propargylic alkynoates provides a reactive platform for complexity generation.
Dominos! The multivalent reactivity profile of tertiaryskippeddiynes has been conveniently exploited in the domino and diversity‐oriented synthesis of fully substituted pyrazoles and 1,4‐diazepane derivatives (see scheme). The developed manifold is chemically efficient and simple to operate. In addition, the resulting N‐containing heterocycles are obtained in a regio‐ and chemoselective manner.
A novel approach to the synthesis of fully substituted pyrimidine derivatives armed with an oxy-functionalized acetate chain at the ring is described. The manifold uses amidines as the nitrogen source and activated skipped diynes as the electrophilic reactive partners in a coupled domino strategy. In the first dominoreaction, two consecutive aza-Michael additions assemble the six-membered ring heterocycle
Diverting is the game! A new domino manifold has been implemented for the synthesis of cyclohexadienone‐based scaffolds fromtertiaryskippeddiynes and secondary amines. The manifold takes advantage of a new O‐enolate‐driven reactivity pattern discovered for these diynes. The scaffolds are conveniently transformed into the corresponding multivalent salicylate derivatives (see scheme).