02509nas a2200241   4500008004100000245014200041210006900183260000800252300001400260490000700274520163100281100001701912700002401929700002401953700001601977700001701993700001902010700003502029700002202064700003002086700002402116856012702140       2017                        eng d00aSecondary interactions arrest the hemiaminal intermediate to invert the modus operandi of schiff base reaction: a route to benzoxazinones0 aSecondary interactions arrest the hemiaminal intermediate to inv  cAPR  a4342-43510 v823 aDiscovered by Hugo Schiff, condensation between amine and aldehyde represents one of the most ubiquitous reactions in chemistry. This classical reaction is widely used to manufacture pharmaceuticals and fine chemicals. However, the rapid and reversible formation of Schiff base prohibits formation of alternative products, of which benzoxazinones are an important class. Therefore, manipulating the reactivity of two partners to invert the course of this reaction is an elusive target. Presented here is a synthetic strategy that regulates the sequence of Schiff base reaction via weak secondary interactions. Guided by the computational models, reaction between 2,3,4,5,6-pentafluoro-benzaldehyde with 2-amino-6methylbenzoic acid revealed quantitative (99%) formation of 5-methyl-2-(perfluoropheny01,2-dihydro-4H-benzo[d][1,3]oxazin-4-one (15). Electron donating and electron withdrawing ortho-substituents on 2-aminobenzoic acid resulted in the production of benzoxazinones 936. The mode of action was tracked using low temperature NMR, IN vis spectroscopy, and isotopic (O-18) labeling experiments. These spectroscopic mechanistic investigations revealed that the hemiaminal intermediate is arrested by the hydrogen-bonding motif to yield benzoxazinone. Thus, the mechanistic investigations and DFT calculations categorically rule out the possibility of in situ imine formation followed by ring-closing, but support instead hydrogen-bond assisted ring-closing to prodrugs. This unprecedented reaction represents an interesting and competitive alternative to metal catalyzed and classical methods of preparing benzoxazinone.1 aPatel, Ketan1 aDeshmukh, Satej, S.1 aBodkhe, Dnyaneshwar1 aMane, Manoj1 aVanka, Kumar1 aShinde, Dinesh1 aRajamohanan, Pattuparambil, R.1 aNandi, Shyamapada1 aVaidhyanathan, Ramanathan1 aChikkali, Samir, H.  uhttps://library.ncl.res.in/content/secondary-interactions-arrest-hemiaminal-intermediate-invert-modus-operandi-schiff-base02077nas a2200181   4500008004100000245010200041210006900143260000800212300001400220490000800234520140600242100002401648700002501672700002201697700002101719700002401740856013101764       2017                        eng d00aSynthesis of meta-substituted monodentate phosphinite ligands and implication in hydroformylation0 aSynthesis of metasubstituted monodentate phosphinite ligands and  cAUG  a1143-11520 v1293 aSynthesis of meta-substituted phosphinite ligands 3,3'-(methoxyphosphanediyl) bis(N, N-diethylaniline) (4a) and methoxybis(3-methoxyphenyl) phosphane (4b), in high yields, has been demonstrated. Typical phosphorus chemical shift between 110-120 ppm, appearance of methoxy protons and corresponding carbon, as well as ESI-MS spectra unambiguously confirmed the existence of phosphinite ligands 4a and 4b. To demonstrate the synthetic usefulness of 4a and 4b, these ligands were tested in the rhodium catalyzed hydroformylation of 1-octene. The diethylamine substituted ligand 4a was found to be highly active, whereas 4bwas less reactive but revealed slightly better regioselectivity of 62% under optimized conditions. Additionally, 4a and 4b were found to catalyze the hydroformylation of styrene, 1-undecenol and 1,1-disubstituted functional olefin, methyl methacrylate. Both the ligands displayed excellent conversion of styrene, and 4b revealed an excellent branch selectivity of 75%. Although 1-undecenol proved to be amenable to hydroformylation (85-90% conversion to aldehyde), both the ligands failed to discriminate between the linear and branched products. Substrate methyl methacrylate proved to be highly challenging and reduced conversion (between 33-42%) was observed under optimized conditions. Ligand 4a was found to be highly selective towards linear aldehyde (81% linear selectivity).1 aDeshmukh, Satej, S.1 aGaikwad, Shahaji, R.1 aPandey, Swechchha1 aMali, Pramod, S.1 aChikkali, Samir, H.  uhttps://library.ncl.res.in/content/synthesis-meta-substituted-monodentate-phosphinite-ligands-and-implication-hydroformylation