Some cyclic ligands obtained from reactions of polycyanocarbon–metal complexes

A Study of [2+2] Cycloaddition–Retroelectrocyclization in Water: Observation of Substrate-driven Transient Nanoreactor Induced New Reactivity

“…These results are intriguing because the previous report by Bruce, with Ru-metal as EDG, did not facilitate such transformation. 11 Interestingly, compound 3a resembles currently practiced cardiotonic drugs such as milrinone and amrinone. 14 Thus opening up a new window for discovering potential drug analogues of new derivatives of this class.…”

“…15,16 Whereas, the H2O addition to EDG-delocalized CN group on 1a to generate 4-donor-substituted merocyanine dye/5-membered heterocycles 2a was proposed by Bruce and co-workers. 11 It was proposed that amide forms an intermediate upon water addition to the TCBD which then further cyclizes to produce amidofulvene. However, we believe that the water addition on 1a generates enol-intermediate-I instead of the keto form, which upon further cyclization provides amidofulvene 2a.…”

“…1,7 So far, the CA-RE reaction of TCNE with electron-rich alkynes generally provides TCBD except in a 2011 report by Bruce and coworkers wherein a ruthenium-substituted lithiated acetylide provided lithiated TCBD intermediate which during the column chromatography (CC) yielded not only TCBD but also 5 and 6-membered heterocycles with the isolated yields of 32, 20, and 16%, respectively without much selectivity (Figure 1b). 11 The formation of amidofulvene was postulated to proceed via water addition on Ru-delocalized nitrile (CN) group to provide amide intermediate which upon subsequent cyclization step furnished amidofulvene. reactivity in water arising as a result of precipitation/insolubility of reactive substrates; (ii) the CA-RE reaction has not been explored beyond the organic electronics device field primarily due to the use of biologically unfriendly solvents which also makes it not a perfect "click reaction" 12 though this reaction is regarded as click-type 1 as it majorly satisfies the criteria set for the click reaction except for the use of organic solvents.…”

The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2014

“…A computational study focused on the electronic structure of iron(II) NHC complexes was also reported [997]. processes involving the coupling of alkynylruthenium complexes and tetracyanoethylene [1015]. A computational study of ruthenium acetylides connected to dithienylperfluorocyclopentene groups focused on protonation, redox processes, and NLO properties [1016].…”

A Study of [2+2] Cycloaddition–Retroelectrocyclization in Water: Observation of Substrate-driven Transient Nanoreactor Induced New Reactivity

“…1b). 11 The formation of amidofulvene was postulated to proceed via water addition on Ru-delocalized nitrile (CN) group to provide amide intermediate which upon subsequent cyclization step furnished amidofulvene. From green chemistry point of view, the use of water as a solvent for organic transformations is an important strategy in synthetic methodology 12 and often provides a unique reactivity and selectivity which is different from organic solvents.…”