Evaluating the Viability of Successive Ring-Expansions Based on Amino Acid and Hydroxyacid Side-Chain Insertion

The outcome of ring expansion reactions based on amino/hydroxyacid side chain insertion is strongly dependent on ring size. This manuscript, which builds upon our previous work on Successive Ring Expansion (SuRE) methods, details efforts to better define the scope and limitations of these reactions on lactam and β-ketoester ring systems with respect to ring size and additional functionality. The synthetic results provide clear guidelines as to which substrate classes are more likely to be successful and are supported by computational results, using a Density Functional Theory (DFT) approach. Calculating the relative Gibbs free energies of the three isomeric species that are formed reversibly during ring expansion enables the viability of new synthetic reactions to be correctly predicted in most cases. The new synthetic and computational results are expected to support the design of new lactam- and β-ketoester-based ring expansion reactions

Domino One-Pot Process for the Synthesis of Isobenzofuran-1(3<i>H</i>)‑ones via [Cu]-Catalysis Using Water as the Green Solvent

An efficient domino one-pot strategy via [Cu]-catalyzed intermolecular “cyanation” of <i>o</i>-bromobenzyl alcohols → in situ intramolecular “nucleophilic attack” → “hydrolysis” is presented, for the synthesis of isobenzofuran-1­(3<i>H</i>)-ones. Significantly, the reaction is successfully carried out under environmentally benign conditions, using water as sole green solvent

Domino One-Pot Process for the Synthesis of Isobenzofuran-1(3<i>H</i>)‑ones via [Cu]-Catalysis Using Water as the Green Solvent

An efficient domino one-pot strategy via [Cu]-catalyzed intermolecular “cyanation” of <i>o</i>-bromobenzyl alcohols → in situ intramolecular “nucleophilic attack” → “hydrolysis” is presented, for the synthesis of isobenzofuran-1­(3<i>H</i>)-ones. Significantly, the reaction is successfully carried out under environmentally benign conditions, using water as sole green solvent

Domino One-Pot Process for the Synthesis of Isobenzofuran-1(3<i>H</i>)‑ones via [Cu]-Catalysis Using Water as the Green Solvent

An efficient domino one-pot strategy via [Cu]-catalyzed intermolecular “cyanation” of <i>o</i>-bromobenzyl alcohols → in situ intramolecular “nucleophilic attack” → “hydrolysis” is presented, for the synthesis of isobenzofuran-1­(3<i>H</i>)-ones. Significantly, the reaction is successfully carried out under environmentally benign conditions, using water as sole green solvent

Domino [Pd]-Catalysis: One-Pot Synthesis of Isobenzofuran-1(3<i>H</i>)‑ones

An efficient domino [Pd]-catalysis for the synthesis of isobenzofuran-1­(3<i>H</i>)-ones is presented. The strategy shows broad substrate scope and is amenable to <i>o</i>-bromobenzyl tertiary/secondary/primary alcohols. Significantly, the method was applied to the synthesis of antiplatelet drug <i>n</i>-butyl phthalide and cytotoxic agonist 3a-[4′-methoxylbenzyl]-5,7-dimethoxyphthalide

Substitution Controlled Functionalization of <i>ortho</i>-Bromobenzylic Alcohols via Palladium Catalysis: Synthesis of Chromenes and Indenols

An efficient domino Pd-catalyzed transformation of simple <i>ortho</i>-bromobenzyl tertiary alcohols to chromenes is presented. Their formation is believed to proceed via the formation of a five-membered palladacycle, which, in turn, involves in an intermolecular homocoupling with the second <i>ortho</i>-bromobenzyltertiary alcohol to yield the homo-biaryl bond followed by intramolecular C–O bond formation. Interestingly, when there is an allylic substituent on the benzylic carbon atom, a chemoselective switch was observed, which preferred intramolecular Heck coupling and gave indenols. Further, it has been confirmed that the tertiary alcohol functionality is indispensible to give the coupled products, whereas the use of primary/secondary benzylic alcohols furnished the simple carbonyl products via a possible reductive debromination followed by oxidation due to the availability of β-hydrogen(s)

[Cu]-catalyzed direct coupling of dibromoalkenes: Synthesis of symmetrical 1,3-diynes and triazoles

<p>An efficient [Cu]-catalyzed homocoupling of 1,1-dibromoalk-1-enes is described for the synthesis of symmetrical 1,3-diyines. The method showed good substrate scope and amenable to aryl and heteroaryl systems. Significantly, the strategy was also successfully applied to the sequential one-pot synthesis of triazoles.</p

Organic transformations catalyzed by palladium nanoparticles on carbon nanomaterials

An efficient C–C bond coupling reactions (Suzuki–Miyaura and Glaser) catalyzed by PdO/GO nano-catalyst is presented. In addition, PdO/MWCNT nano-catalyst-mediated domino one-pot synthesis of 2-alkyl/2-aryl benzofurans has been accomplished from 2-iodophenols and terminal alkynes. The formation of benzofurans proceeds through intermolecular Sonogashira reaction followed by intramolecular nucleophilic addition of internal hydroxyl group onto the acetylenic bond. The catalyst PdO/GO has been reused successfully, with nearly no loss of activity up to 5 cycles

Simple, Copper(I)-Catalyzed Oxidation of Benzylic/Allylic Alcohols to Carbonyl Compounds: Synthesis of Functionalized Cinnamates in One Pot

<div><p></p><p>An environmentally benign [Cu(I)]-catalyzed oxidation of activated (benzylic/allylic) alcohols to the corresponding carbonyl compounds is presented. Interestingly, the reaction was also compatible with benzylic alcohols containing ortho-bromo substituents on the aromatic ring without competing with the expected intermolecular Buchwald coupling. Significantly, the catalytic system enables the synthesis of cinnamate-esters in a sequential domino one-pot fashion via oxidation followed by Wittig–Horner protocol.</p> </div