Motatipally Damoder Reddy

A thioannulation approach to substituted thiophenes from Morita-Baylis-Hillman acetates of acetylenic aldehydes.

A new protocol has been developed for the synthesis of substituted thiophenes under mild and metal-free reaction conditions via the base-promoted thioannulation of Morita-Baylis-Hillman acetates of acetylenic aldehydes with potassium thioacetate involving a tandem allylic substitution/deacetylative 5-exo-dig-thiocycloisomerization. The obtained products provide an entry to 4H-thieno[3,2-c]chromene and thieno[3,2-c]dihydroquinoline.

A Metal-Free Tandem C–C/C–O Bond Formation Approach to Diversely Functionalized Tetrasubstituted Furans

A novel and efficient method for the synthesis of diversely functionalized furans is developed via DBU-mediated tandem Michael addition/5-exo-dig-cycloisomerization of enynes and keto-methylenes. This [3 + 2]-annulation is operationally simple under metal-free reaction conditions with 100% atom economy and broad substrate scope.

Novel [4 + 2]-benzannulation to access substituted benzenes and polycyclic aromatic and benzene-fused heteroaromatic compounds.

A common [4 + 2]-benzannulation of Morita-Baylis-Hillman acetates of acetylenic aldehydes with boronic acids has been developed for the synthesis of aromatic and heteroaromatic compounds through tandem allylic substitution/hydroarylative cycloisomerization process. This method provides a facile and general route to substituted benzenes, naphthalenes, other polycyclic aromatics, and various benzene-fused heteroaromatic compounds such as benzofuran, benzothiophene, indole, and carbazoles.

Aza-Annulation of Enynyl Azides: A New Approach to Substituted Pyridines

Synthesis of substituted pyridines through a novel aza-annulation of 2-en-4-ynyl azides, derived from MBH-acetates of acetylenic aldehydes, is described. A variety of enynyl azides having aryl, heteroaryl, and alkyl groups on the alkyne functionality successfully participated in the Ag-mediated annulation reaction to provide the corresponding 3,6-disubstituted pyridines. I2-mediated cyclization was found to be controlled by the substituent on the alkyne functionality, which offered the 5-iodo-3,6-disubstituted pyridines from enynyl azides having an electron-rich substituent on the alkyne functionality.