Manickam Bakthadoss

Solid-state melt reaction for the domino process: highly efficient synthesis of fused tetracyclic chromenopyran pyrimidinediones using Baylis-Hillman derivatives.

A solid-state melt reaction (SSMR) has been demonstrated via a domino process for the synthesis of tetracyclic chromenopyran pyrimidinedione frameworks using Baylis-Hillman derivatives through in situ formation of an olefin followed by an intramolecular [4 + 2] cycloaddition reaction sequence. The tetracyclic frameworks were obtained without using catalyst and solvent in a highly stereoselective and stereospecific fashion. The isolated yield is excellent and does not require column chromatography purification to obtain the pure product.

A multicomponent cascade reaction for the synthesis of novel chromenopyranpyrazole scaffolds

A catalyst, solvent, work-up and column free synthesis of chromenopyranpyrazoles via multicomponent cascade reaction has been achieved with high stereoselectivity. This novel reaction creates two N-C, two C-C and one O-C bonds through a domino process for the construction of three new rings and three contiguous stereogenic centers.

A novel synthesis of tetra and pentacyclic quinolinopyran tethered pyrazole/coumarin scaffolds via a solid state melt reaction

A new protocol has been developed for the efficient synthesis of structurally diverse tetra- and pentacyclic quinolinopyran tethered pyrazole/coumarin architectures via a domino Knoevenagel intramolecular hetero-Diels–Alder (IMHDA) strategy using a solid state melt reaction (SSMR) in a highly diastereo and regioselective fashion. Gratifyingly, these heterocyclic frameworks were synthesized under solvent and catalyst free conditions, without the aid of a work-up and column chromatography purification. The generality and functional tolerance of this convergent and environmentally benign method is very attractive.

(1R, 2R)-2-nitroxycyclohexan-1-ol : First example of a cyclohexyl based chiral auxiliary with nitroxy function as diastereoface discriminating group

Application of nitroxy substituent as diastereoface discriminating group in a cyclohexyl based chiral auxiliary has been described.

Simple and New Protocol for the Synthesis of Novel (z)-3-Arylidenebenzothiazepin-4-ones Using Baylis-Hillman Derivatives

Abstract A simple synthesis of novel (Z)-3-arylidene-2,3-dihydrobenzo[b][1,4]thiazepin-4(5H)-ones from bromo compounds derived from Baylis–Hillman adducts involving selective S-alkylation followed by a lactum formation has been described.

TANDEM CONSTRUCTION OF CARBON–CARBON AND CARBON–OXYGEN BONDS IN THE BAYLIS-HILLMAN CHEMISTRY: SYNTHESIS OF FUNCTIONALIZED dl-BIS-ALLYL ETHERS

ABSTRACT Tandem coupling between acrylonitrile and aryl aldehydes under the catalytic influence of DABCO involving the construction of two carbon–carbon bonds and one carbon–oxygen bond leading to the synthesis of dl-functionalized bis-allyl ethers has been described.

A new protocol for the syntheses of (E)-3-benzylidenechroman-4-ones: a simple synthesis of the methyl ether of bonducellin

Development of a simple new methodology for the synthesis of (E)-3-benzylidenechroman-4-ones using methyl 3-aryl-3-hydroxy-2-methylenepropanoates, the Baylis–Hillman adducts derived from methyl acrylate, and the application of this methodology for the synthesis of the methyl ether of bonducellin, an important natural product, and 3-(4-methoxybenzylidene)-6-methoxychroman-4-one, an antifungal agent, are described.

Synthesis of highly diversified 1,2,3-triazole derivatives via domino [3 + 2] azide cycloaddition and denitration reaction sequence

In this paper, an elegant synthesis of 1,2,3-triazole derivatives via domino [3 + 2] azide cycloaddition and denitration reaction sequence under catalyst free conditions has been described. Treatment of Baylis–Hillman adducts and their cyclic derivatives from nitroolefins with sodium azide in the absence of catalyst smoothly afforded the 1,2,3-triazole derivatives in excellent yields.

A Simple and Direct Synthesis of 3-Methylene-1, 4-diarylazetidin-2-ones and (E)-3-Arylidene-1-phenylazetidin-2-ones Using Baylis–Hillman Derivatives

Herein we describe a direct method, promoted by potassium tert-butoxide (KOtBu), for the synthesis of highly substituted α-methylene β-lactams and α-arylidene β-lactams from the amino ester intermediates derived from the acetates and bromo derivatives of the Baylis–Hillman adducts. A variety of β-lactams was synthesized in a single step with good yields.

One-Pot Synthesis of Benzothiazole-Tethered Chromanones/Coumarins via Claisen Rearrangement Using the Solid State Melt Reaction.

A novel protocol has been successfully established for the efficient synthesis of benzothiazole-tethered chromanone/coumarin scaffolds via Claisen rearrangement using a solid state melt reaction in a one-pot manner. Benzothiazole formation and Claisen rearrangement involve the cleavage of S-S and C-O bonds and formation of C-S, C═N, and C-C bonds in a single operation without using a catalyst or solvent.