01151nas a2200169   4500008004100000245009700041210006900138260000800207300001600215490000700231520054600238100001700784700002000801700001500821700001900836856012600855       2017                        eng d00aTransition metal free catalytic hydroboration of aldehydes and aldimines by amidinato silane0 aTransition metal free catalytic hydroboration of aldehydes and a  cFEB  a2420 - 24240 v463 aThe transition metal free catalytic hydroboration of aldehydes and ketones is very limited and has not been reported with a well-defined silicon(iv) compound. Therefore, we chose to evaluate the previously reported silicon(iv) hydride [PhC(NtBu)2SiHCl2], (1) as a single component catalyst and found that it catalyzes the reductive hydroboration of a range of aldehydes with pinacolborane (HBpin) under ambient conditions. In addition, compound 1 can catalyze imine hydroboration. DFT calculation was carried out to understand the mechanism.1 aBisai, Milan1 aPahar, Sanjukta1 aDas, Tamal1 aSen, Sakya, S.  uhttps://library.ncl.res.in/content/transition-metal-free-catalytic-hydroboration-aldehydes-and-aldimines-amidinato-silane01965nas a2200193   4500008004100000022001500041245010400056210006900160260000800229300001400237490000700251520128700258100001801545700002401563700001501587700001701602700002801619856012401647       2018                        eng d  a 2192-650600a Twelve-armed hexaphenylbenzene-based giant supramolecular framework for entrapping guest molecules0 aTwelvearmed hexaphenylbenzenebased giant supramolecular framewor  cNOV  a1032-10370 v833 a<p>Host-guest chemistry is a functional model in supramolecular chemistry for understanding specific process occurring in biological systems. Herein, we describe a rationally designed giant multiarmed hexaphenylbenzene (HPB)-based supramolecular frameworks which encapsulate a variety of guest molecules in the voids of their crystal lattice through the cooperative interplay of multivalency, noncovalent forces and backbone rigidity. In this connection, pseudo-axially substituted twelve-armed hexaphenylbenzene was synthesized and its molecular entrapping nature was studied by varying number of H-bond donor-acceptor sites in the arms. The per-methyl esterified HPB acted as a cavitand to include nonpolar and polar aprotic guests in its crystal structure via C-H center dot center dot center dot pi, C-H center dot center dot center dot O and C-H center dot center dot center dot N interactions. The corresponding amidated HPB showed unprecedented inclusion of ammonia and segregation of the guest molecules according to their polarity in the lattice. Furthermore, this molecular entrapping system has been used to obtain the crystal structure of a hitherto unproven 2-azaallenium intermediate, which had been proposed to be involved in aminomethylation of activated arenes.</p>1 aMadhu, Suresh1 aGonnade, Rajesh, G.1 aDas, Tamal1 aVanka, Kumar1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/twelve-armed-hexaphenylbenzene-based-giant-supramolecular-framework-entrapping-guest02071nas a2200289   4500008004100000022001400041245015700055210006900212260000900281300001100290490000800301520110100309653002101410653001501431653001201446653001601458653001301474653002101487100002401508700002301532700001501555700002101570700001901591700001701610700002301627856013101650       2020                        eng d  a0022-328X00aTransmetallation vs adduct: diverse reactivity of N,O-ketiminato germylene with [Cp*MCl2](2) (M = Rh or Ir; Cp* = eta(5)-C5Me5) and MCl5 (M = Nb and Ta)0 aTransmetallation vs adduct diverse reactivity of NOketiminato ge  cAPR   a1211420 v9113 a<p>The reactions of the germylenes, [(Dipp)NCMeCHCORGeCl] (1a: R = Me, 1b: R = Ph) with [Ir2Cl2(mu-Cl)(2)(eta(5)-Cp*)(2)] led to the formation of the adducts [(Dipp)NCMeCHCORGeClIrCl2Cp*] (3a: R = Me and 3b: R = Ph). On the other hand, [Rh2Cl2(mu-Cl)(2)(eta(5)-Cp*)(2)] does not react with the germylenes (1a and 1b). When the reactions of 1a and 1b are carried out with [Cp*TaCl4], the reaction led to decomposition. The reaction of 1a or 1b with TaCl5 yielded the transmetallated products [(Dipp)NCMeCHCORTaCl4] (4a: R = Me, 4b: R = Ph) with the extrusion of GeCl2. Our theoretical studies show that for, the insertion of TaCl5 to 1a and the formation of 4a with concomitant elimination of GeCl2 is energetically favourable. Extrusion of SnCl2 is also observed when the corresponding stannylene, [(Dipp)NCMeCHCOMeSnCl] was reacted with TaCl5. All these compounds have been characterized by H-1 and C-13 NMR spectroscopy, elemental analysis and the constitution of compounds 1b, 3b, and 4a were confirmed by single-crystal X-ray crystallography. (C) 2020 Elsevier B.V. All rights reserved.</p>
10aAdduct formation10aGermylenes10aIridium10aKetoiminate10aTantalum10aTransmetallation1 aRaghavendra, Beesam1 aBakthavachalam, K.1 aDas, Tamal1 aRoisnel, Thierry1 aSen, Sakya, S.1 aVanka, Kumar1 aGhosh, Sundargopal  uhttps://library.ncl.res.in/content/transmetallation-vs-adduct-diverse-reactivity-no-ketiminato-germylene-cpmcl22-m-rh-or-ir-cp