01744nas a2200217   4500008004100000022001400041245007000055210006700125260000800192490000700200520104300207653002701250653001401277653001901291653003101310653001301341100002101354700002401375700002401399856010301423       2021                        eng d  a1527-899900aGold-catalysed nitroalkyne cycloisomerization - synthetic utility0 aGoldcatalysed nitroalkyne cycloisomerization synthetic utility  cDEC0 v213 a<p>The gold-catalysed intramolecular redox cyclization of o-alkynylnitrobenzens documented by Professors Naoki Asao and Yoshinori Yamamoto is an important discovery that has opened two complementary research domains. Advancing this cyclization with other metals as well as developing new methods around the products that result from this reaction is one aspect that has seen growing interest. On the other hand, the idea of generating alpha-oxo gold carbenes via oxygen transfer to alkynes has established another important aspect in gold-catalysis. In this account, we will be dealing with the first aspect, which revolves around the internal redox cyclization of nitroalkynes (trivially called as nitroalkyne cycloisomerization), focusing mainly on the gold-complexes and the synthetic methods developed around it from our group and from other groups, and also providing the details of similar transformations documented with other metals so that the complementary reactivity/diversity of these transformations could be appreciated.</p>10aalpha-Oxo Gold Carbene10aAnthranil10aGold-catalysis10aInternal Redox Cyclization10aIsatogen1 aDhote, Pawan, S.1 aHalnor, Swapnil, V.1 aRamana, Chepuri, V.  uhttps://library.ncl.res.in/content/gold-catalysed-nitroalkyne-cycloisomerization-synthetic-utility01311nas a2200241   4500008004100000022001400041245008500055210006900140260000900209300001400218490000700232520053600239653001900775653003500794653001600829653001200845653001700857653001300874100002600887700002400913700002400937856010800961       2023                        eng d  a0039-788100aRh-catalyzed C-H functionalization of the (Pyrazol-5-yl)pyridine core of GBT-4400 aRhcatalyzed CH functionalization of the Pyrazol5ylpyridine core   cNOV   a3600-36090 v553 a<p>
	The Rh-catalyzed cross dehydrogenative coupling (CDC)/alkylation of the pyrazolylpyridine unit of GBT-440 proceeded smoothly under ambient conditions and selectively on the pyrazole unit while directed by the pyridine. The scope of these reactions was established by employing simple as well as conjugated olefins for CDC and various diazo esters and the TIPS-EBX reagent for alkylation. At the outset, a focused small molecule library around the bis-heterocyclic core of GBT440 was developed via C-H functionalization.</p>
10aC-H activation10across dehydrogenative coupling10adiazo ester10aGBT-44010aRh catalysis10aTIPS-EBX1 aKalshetti, Rupali, G.1 aHalnor, Swapnil, V.1 aRamana, Chepuri, V.  uhttps://library.ncl.res.in/content/rh-catalyzed-c-h-functionalization-pyrazol-5-ylpyridine-core-gbt-44001318nas a2200205   4500008004100000022001400041245018000055210006900235260000900304300001100313490000800324520049900332653001400831653001900845653003900864653003500903100002400938700002400962856012600986       2024                        eng d  a0040-402000aAttempted synthesis of the central 2,2-disubstituted pseudoindoxyl core of Austamide via a [Au]-catalyzed nitroalkyne cycloisomerization and intramolecular [3+2]-cycloaddition0 aAttempted synthesis of the central 22disubstituted pseudoindoxyl  cNOV   a1343010 v1673 a<p>
	Herein, we describe an Au-catalyzed cycloisomerization process of a nitroalkyne that was projected to construct the central 2,2-disubstituted pseudoindoxyl core of the natural product Austamide. Our intended strategy for forging the pseudoindoxyl core is based on the nitroalkyne cycloisomerization followed by a subsequent intramolecular [3 + 2] cycloaddition. However, the [3 + 2] cycloaddition occurred in an undesired manner, ultimately leading to a complex hexacyclic scaffold.</p>
10aAustamide10aGold catalysis10aIntramolecular [3+2] cycloaddition10aNitroalkyne cycloisomerization1 aHalnor, Swapnil, V.1 aRamana, Chepuri, V.  uhttps://library.ncl.res.in/content/attempted-synthesis-central-22-disubstituted-pseudoindoxyl-core-austamide-au-catalyzed01236nas a2200181   4500008004100000022001400041245013800055210006900193260000900262300001600271490000700287520053900294100002400833700002000857700002100877700002400898856013200922       2024                        eng d  a0022-326300aSynthesis of tetracyclic benzoxazolo-indol-3-ones from isatogens and arynes through a [3+2]-cycloaddition and skeletal reorganization0 aSynthesis of tetracyclic benzoxazoloindol3ones from isatogens an  cOCT   a14919-149280 v893 a<p>
	The construction of an unprecedented tetracyclic benzoxazolo-indol-3-one scaffold has been executed through the [3 + 2]-cycloaddition of isatogens with arynes. The initially formed benzisoxazolo-indol-3-one intermediate undergoes a skeletal reorganization through a 1,3-sigmatropic shift/retro-Mannich reaction with the net formation of one C-N and two C-O bonds. The Lewis acid-catalyzed allylation of some of the resulting benzoxazolo-indol-3-ones resulted in oxazepino-indolones with promising photophysical properties.</p>
1 aHalnor, Swapnil, V.1 aSingh, Maneesha1 aDhote, Pawan, S.1 aRamana, Chepuri, V.  uhttps://library.ncl.res.in/content/synthesis-tetracyclic-benzoxazolo-indol-3-ones-isatogens-and-arynes-through-32-cycloaddition