02259nas a2200277 4500008004100000245015100041210006900192260000800261300001600269490000600285520129900291653001801590653002801608653000801636653002001644653003001664653002401694100002001718700001901738700001801757700002101775700001701796700001701813700002001830856013101850 2025 eng d00aBioinspired synthesis of bridged isochromane fused pyrazoles by a silver catalyzed cascade reaction and its application for antibacterial activity0 aBioinspired synthesis of bridged isochromane fused pyrazoles by  cAUG a4184–41950 v53 a

A stereoselective silver catalyzed one pot vinylogous aldol addition followed by a cascade [4+2] cycloaddition reaction of α-arylidene pyrazolinones to in situ generated isochromenylium ions has been developed, which provides an unprecedented bridged [2.2.2] [3.3.1] pentacyclic [5-6-6-6-6] skeleton consisting of an isochroman, chroman, and a pyrazole unit in one molecule with good to high yields as a single diastereomer. This method offers mild reaction conditions, wide substrate compatibility, excellent scalability and easy derivatization. A DFT study was carried out to clarify the reaction mechanism. It was exciting to observe that the unprecedented bridged isochromans synthesized here have shown excellent selectivity toward Gram-positive and Gram-negative bacteria. We demonstrate that while some structures are broad spectrum antibacterial there are two distinct structures that can be explored for selective activity.

10aAntibacterial10aBridged [2.2.2] [3.3.1]10aROS10aStereoselective10aVinylogous aldol addition10a[4+2] cycloaddition1 aSingh, Bhuvnesh1 aTewari, Shreya1 aKaur, Manleen1 aSharma, Himanshu1 aVanka, Kumar1 aSingh, Neetu1 aSingh, Ravi, P. uhttps://library.ncl.res.in/content/bioinspired-synthesis-bridged-isochromane-fused-pyrazoles-silver-catalyzed-cascade-reaction