Towards Waltheriones C and D: Synthesis of the Oxabicyclic Core

A route to the oxabicyclic cores of the HIV cytoprotective
quinolone alkaloids, waltheriones C and D, is described. The approach
relies on a stereospecific transannular bromoetherification followed by
reductive debromination. The route can also be rendered enantioselective
via enzymatic reduction of a key intermediate (>99:1 er).

Target cum flexibility: an alkyne [2+2+2]-cyclotrimerization strategy for synthesis of trinem library

A rapid access to the central 4,5,6-tricyclic core of 4,5,6-trinems has been achieved by employing the alkyne [2+2+2]-cyclotrimerization as the key and final reaction in the synthesis.

A Pd-mediated intramolecular ketalization of alkynediols: construction of the central [3.2.1]-bicyclic ketal core of cyclodidemniserinol trisulfate

A preliminary study dealing with the Pd-mediated alkynediol cycloisomerization to construct the central bicyclic ketal core of cyclodidemniserinol trisulfate is documented.

The influence of electronic factors on palladium-mediated cycloisomerization: a systematic investigation of competitive 5-exo-dig versus 6-endo-dig cyclizations of sugar alkynols

Pd-mediated cycloisomerization of 3-C-alkynyl-allo- and ribofuranose derivatives was investigated in detail to understand the influence of electronic factors on the regioselectivity in ring closure reaction. The reactions in general are influenced by the electronic nature of the substituent on the alkyne unit. A preference for endo-dig cyclization over exo-dig is noted, if the alkynyl substituent is not sufficiently electron withdrawing.

Palladium mediated cycloisomerization of sugar alkynols: synthesis of cyclic enol-ethers and spiroketals

Functionalized bicyclic enol-ethers and spiroketals are prepared by Pd catalyzed cycloisomerization of 3-C-alkynylfuranosyl derivatives. Cycloisomerization of differently substituted alkyne derivatives revealed a preference for 6-endo-dig cyclization over 5-exo-dig if the substituent is not sufficiently electron withdrawing. The scope of these cycloisomerizations has been further extended by integrating with conjugate addition.

In silico Screening of Myristica fragrans extracts licarin A, licarin B, licarin C, malabaricone B and malalabaricone C for their activity towards a methionine aminopeptidase type II.

Estimation of Binding Affinity of Selected Nutmeg Phytochemicals with Human hypocretin-2/Orexin-B by In Silico Molecular Docking to Evaluate Their Inhibitory Activity.

Transition Metal Catalyzed Hydroalkoxylation of Alkynes: An Overview

Oxygen - bearing motifs, mainly the congener heterocycles are ubiquitous due to their presence in various natural products and bioactive scaffolds. Although in literature, several strategies have been developed for their synthesis, hydroalkoxylation of alkynes has come forward as a method of choice and has been used extensively. In particular, hydroalkoxylation of alkynes has gained enormous attention from the synthetic community due to the rapid access to a very useful and reactive synthetic intermediate like ‘enol ether’. Furthermore, to manifold the utility of these methods, reports have been developed elaborating the generation of ‘enol ether’ using hydroalkoxylation and their usage in various reactions in cascade or tandem manner. This review focuses on recent development on the hydroalkoxylation of alkynes for the synthesis of oxygen - containing entities.

Organocatalytic Enantiospecific Total Synthesis of Butenolides

Biologically important, chiral natural products of butenolides, (?)-blastmycinolactol, (+)-blastmycinone, (?)-NFX-2, (+)-antimycinone, lipid metabolites, (+)-ancepsenolide, (+)-homoancepsenolide, mosquito larvicidal butenolide and their analogues were synthesized in very good yields in a sequential one-pot manner by using an organocatalytic reductive coupling and palladium-mediated reductive deoxygenation or organocatalytic reductive coupling and silica-mediated reductive deamination as the key steps

Organocatalytic Enantiospecific Total Synthesis of Butenolides

Biologically important, chiral natural products of butenolides, (?)-blastmycinolactol, (+)-blastmycinone, (?)-NFX-2, (+)-antimycinone, lipid metabolites, (+)-ancepsenolide, (+)-homoancepsenolide, mosquito larvicidal butenolide and their analogues were synthesized in very good yields in a sequential one-pot manner by using an organocatalytic reductive coupling and palladium-mediated reductive deoxygenation or organocatalytic reductive coupling and silica-mediated reductive deamination as the key steps

Transition Metal?Catalyzed Hydroalkoxylation of Alkynes: An Overview

Oxygen-bearing motifs, mainly the congener heterocycles are ubiquitous due to their presence in various natural products and bioactive scaffolds. Although in literature, several strategies have been developed for their synthesis, hydroalkoxylation of alkynes has come forward as a method of choice and has been used extensively. In particular, hydroalkoxylation of alkynes has gained enormous attention from the synthetic community due to the rapid access to a very useful and reactive synthetic intermediate like ‘enol ether’. Furthermore, to manifold the utility of these methods, reports have been developed elaborating the generation of ‘enol ether’ using hydroalkoxylation and their usage in various reactions in cascade or tandem manner. This review focuses on recent development on the hydroalkoxylation of alkynes for the synthesis of oxygen-containing entities.

1, 2-Difunctionalizations of alkynes entailing concomitant C–C and C–N bond-forming carboamination reactions

Vicinal carboamination of alkynes is a highly reliable and efficient practical strategy for the quick preparation of valuable and diverse amine derivatives starting from simple synthons. The last decade has witnessed numerous practical methods employing transition-metal-based/metal-free carboamination approaches using alkynes for the synthesis of these N-bearing entities. Driven by the renaissance of transition metal catalysis, intermolecular and intramolecular carboamination of alkynes comprising concomitant C–N and C–C bond formation has been studied extensively. In contrast to metal catalysis, though analogous metal-free approaches have been relatively less explored in the literature, they serve as alternatives to these expensive approaches. Despite this significant progress, reviews documenting such examples are sporadic; as a result, most reports of this type remained scattered throughout the literature, thereby hampering further developments in this escalating field. In this review, different conceptual approaches will be discussed and examples from the literature will be presented. Further, the reader will get insight into the mechanisms of different transformations.

Transition Metal?Catalyzed Carboamination of Alkenes and Allenes: Recent Progress

Vicinal carboamination of carbon-carbon multiple bonds is a highly reliable and efficient practical strategy for the quick preparation of valuable and diverse amine derivatives starting from simple synthons. The last decade has witnessed numerous practical methods employing transition metal carboamination approaches of alkenes and allenes for the synthesis of these N-bearing entities. Driven by the renaissance of transition metal catalysis, inter-and intramolecular carboamination of alkenes and allenes comprising concomitant C?N and C?C bond formation has been studied extensively. Interestingly, existing reviews describing developments on carboamination of alkenes are mostly reaction path specific and confined to a particular metal catalyst. Whereas, guiding congregation of literature on carboamination of allene is not documented. In this review, different conceptual approaches will be discussed and examples from the recent literature will be presented with special focus to the detailed reaction mechanism.

Vicinal carboamination of carbon-carbon multiple bonds is a highly reliable and efficient practical strategy for the quick preparation of valuable and diverse amine derivatives starting from simple synthons. The last decade has witnessed numerous practical methods employing transition metal carboamination approaches of alkenes and allenes for the synthesis of these N-bearing entities. Driven by the renaissance of transition metal catalysis, inter-and intramolecular carboamination of alkenes and allenes comprising concomitant C?N and C?C bond formation has been studied extensively. Interestingly, existing reviews describing developments on carboamination of alkenes are mostly reaction path specific and confined to a particular metal catalyst. Whereas, guiding congregation of literature on carboamination of allene is not documented. In this review, different conceptual approaches will be discussed and examples from the recent literature will be presented with special focus to the detailed reaction mechanism.