7785-70-8Relevant academic research and scientific papers
Temperature Controls Guest Uptake and Release from Zn4L4 Tetrahedra
Zhang, Dawei,Ronson, Tanya K.,Güryel, Songül,Thoburn, John D.,Wales, David J.,Nitschke, Jonathan R.
supporting information, p. 14534 - 14538 (2019/10/11)
We report the preparation of triazatruxene-faced tetrahedral cage 1, which exhibits two diastereomeric configurations (T1 and T2) that differ in the handedness of the ligand faces relative to that of the octahedrally coordinated metal centers. At lower temperatures, T1 is favored, whereas T2 predominates at higher temperatures. Host-guest studies show that T1 binds small aliphatic guests, whereas T2 binds larger aromatic molecules, with these changes in binding preference resulting from differences in cavity size and degree of enclosure. Thus, by a change in temperature the cage system can be triggered to eject one bound guest and take up another.
[(NHC)CoR2]: pre-catalysts for homogeneous olefin and alkyne hydrogenation
Enachi, Andreea,Baabe, Dirk,Zaretzke, Marc-Kevin,Schweyen, Peter,Freytag, Matthias,Raeder, Jan,Walter, Marc D.
supporting information, p. 13798 - 13801 (2018/12/14)
A novel synthesis for dialkyl cobalt compounds [(tmeda)CoR2] is presented. In these complexes tmeda is readily replaced by an NHC or a bidentate phosphine ligand to form 3- and 4-coordinate compounds, respectively. [(ItBu)Co(CH2SiMe3)2] (ItBu = 1,3-di-tert-butylimidazolin-2-ylidene) serves as an efficient, homogeneous olefin hydrogenation pre-catalyst and allows the preparation of the novel cobalt bis(alkyne) complex [(ItBu)Co(η2-PhCCPh)2].
An improved and efficient synthesis of pinene based bipyridyldiols and bipyridine
Boobalan, Ramalingam,Chen, Chinpiao
supporting information, p. 1930 - 1934 (2016/04/19)
An improved and efficient synthesis of pinene based two bipyridyldiols and bipyridine is reported. For the first time, the sealed tube-pressure reaction of pinene based pyridone with phosphoryl chloride produced an excellent yield (95%) of pinene based 2-chloropyridine, which renders synthesizing pinene based bipyridyldiols a highly inexpensive and high yielding process. Moreover, highly effective reaction condition was developed for homocoupling of chloropyridine with Ni(0) that afforded pinene based bipyridine in a high yield (84%). These newly demonstrated sealed tube-pressure chlorination and homocoupling reaction of chloropyridine afford extremely effect route for the synthesis of pinene based bipyridine.
ODORANT COMPOSITION CONTAINING ALLYL ETHERS AS ODORANT PRECURSORS
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Paragraph 0123, (2014/02/16)
The deliberate release of odorants or aroma substances is desirable in many fields of application, and in particular in the field of washing and cleaning agents. Said deliberate release is achieved by using an odorant composition that comprises an odorant precursor, which is an allyl ether of the formula (I), R1R2C═CR3—CR4R5—O—CHR6R7, in which the residues R1, R2, R3, R4, R5, R6 and R7 mutually independently denote H or a hydrocarbon residue that can be acyclic or cyclic, substituted or unsubstituted, branched or unbranched, as well as saturated or unsaturated. Thus, in particular odorants in the form of an alkene having an allylic hydrogen atom, such as α-pinene, can be released in a deliberate manner.
Synthesis of nopol via Prins condensation of β-pinene and paraformaldehyde catalyzed by sulfated zirconia
Jadhav, Sumit V.,Jinka, Krishna Mohan,Bajaj, Hari C.
scheme or table, p. 158 - 165 (2011/12/21)
The present work describes the novel application of sulfated zirconia (SZ) solid acid catalysts for the synthesis of nopol via Prins condensation of β-pinene and paraformaldehyde. SZ catalysts with different percentages of sulfur loadings have been synthesized and characterized using various physico-chemical techniques like PXRD, FT-IR, surface area analysis and NH 3-TPD studies. The influences of various reaction parameters such as sulfur loading, reaction temperature, molar ratio of reactants, reaction time, solvent effect and reusability of the catalyst have been investigated. SZ catalyst synthesized by impregnation of 2N sulfuric acid solution over Zr(OH)4 was found to be a highly selective catalyst for β-pinene conversion (>99%) with ～99% selectivity to nopol. The catalyst could be reused up to five cycles with minor loss in catalytic activity for β-pinene conversion, while the nopol selectivity remains unaffected.
Synthesis of silylated alkylboronic acids and esters via hydroboration of allylic and vinylic trimethylsilanes
Cytarska,Kaczanowska,Zaidlewicz
, p. 1587 - 1594 (2008/09/18)
Representative allylic trimethylsilanes and isopropenyltrimethylsilane were hydroborated with dichloroborane, and the products were transformed into the corresponding ssor γ-trimethylsilylboronates. Synthesis of 2-trimethylsilylethylboronic acid and its diethyl ester via hydroboration of trimethylvinylsilane with diisopinocampheylborane, followed by liberation of α-pinene is described.
Regio- and stereoselective synthesis of the enantiomers of monoterpene-based β-amino acid derivatives
Szakonyi, Zsolt,Martinek, Tamas A.,Sillanpaeae, Reijo,Fueloep, Ferenc
, p. 2442 - 2447 (2008/03/13)
The regio- and stereospecific addition of chlorosulfonyl isocyanate to cis-δ-pinene enantiomers has furnished monoterpene-fused β-lactams. The observed regioselectivity can be explained by ab initio DFT modeling of transition state structures. In contrast with the less reactive α-pinane-fused β-lactam 4, the resulting β-lactams 5 and 13 containing an amino group connected to a secondary carbon possess similar reactivity to the cycloalkane-fused analogues and can be easily converted to the β-amino acid and its protected derivatives. The base-catalyzed isomerization of the cis-amino ester afforded the corresponding trans-amino ester in moderate yield.
Incorporation of an allene unit into α-pinene via β- elimination
Kilbas, Benan,Azizoglu, Akin,Balci, Metin
, p. 1449 - 1456 (2007/10/03)
The two double-bond isomers 3-iodo-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene (6b) and 3-iodo-4,6,6-trimethylbicyclo[3.1.1]hept-2-ene (11) were synthesized by reacting 2,6,6-trimethylbicyclo[3.1.1]heptan-3-one (9) with hydrazine, followed by treatment with I2 in the presence of Et3N. Treatment of 11 with t-BuOK as base in diglyme at 220 resulted in the formation of 9 and 6,6-dimethyl-4-methylidenebicyclo[3.1.1]hept-2-ene (12). For the formation of 9, the cyclic allene 7 is proposed as an intermediate. Treatment of the second isomer, 6b, with t-BuOK at 170 gave rise to the diene 12 and the dimerization product 17. The underlying mechanism of this transformation is discussed. On the basis of density-functional-theory (DFT) calculations on the allene 7 and the alkyne 15, the formation of the latter as the intermediate was excluded. Verlag Helvetica Chimica Acta AG.
Molecular addition compounds. 14. Convenient preparations of representative dialkylborane reagents using the new, highly reactive N- ethyl-N-isopropylaniline-borane reagent (BACH-EI(TM))
Brown, Herbert C.,Kanth, Josyula V. B.,Zaidlewicz, Marek
, p. 5991 - 6000 (2007/10/03)
Convenient procedures for the preparation of representative dialkylborane reagents, diisopinocampheylborane, [1S]-2-diisocaranylborane, 9-borabicyclo[3,3,1]nonane, dicyclohexylborane and disiamylborane, using the new, highly reactive N-ethyl-N-isopropylaniline-borane reagent (BACH-EI(TM)) in dioxane and tetrahydrofuran are described.
Chiral synthesis via organoboranes. 48. Efficient synthesis of trans- fused bicyclic and cyclic ketones and secondary alcohols in high optical purities via asymmetric cyclic hydroboration with isopinocampheylchloroborane etherate
Dhokte, Ulhas P.,Pathare, Pradip M.,Mahindroo, Verinder K.,Brown, Herbert C.
, p. 8276 - 8283 (2007/10/03)
Highly stereo- and enantioselective annelation has been achieved for the synthesis of trans-fused bicyclic and cyclic ketones via the asymmetric cyclic hydroboration of suitable cyclic dienes, such as 1-allyl-1- cycloalkenes or 1-vinyl-1-cycloalkenes and appropriate acyclic 1,4-dienes, respectively, with enantiomerically pure isopinocampheylchloroborane etherate (IpcBHCl·Et2O). The IpcBHCl· Et2O (an 86-90% equilibrium mixture) was readily synthesized by the reaction of an equivalent amount of hydrochloric acid in ethyl ether (Et2O) with optically pure isopinocampheylborane (IpcBH2). The hydroboration of the terminal double bond of a representative diene with IpcBHCl·Et2O readily provided the corresponding isopinocampheylalkylchloroborane (IpcRBCl). Subsequent hydridation of the IpcRBCl with lithium aluminum hydride (LAH, 0.25 equiv) at -20 or -25 °C generated the intermediate isopinocampheylalkylborane (IpcRBH) almost instantly, which then underwent a rapid stereospecific and enantioselective intramolecular cyclic hydroboration to provide the intermediate cyclic trialkylborane. This trialkylborane, on treatment with an aldehyde, liberated the optically pure auxiliary as α-pinene (readily recovered for recycle) to provide the corresponding cyclic borinate ester. This ester reacted smoothly with α,α-dichloromethyl methyl ether (DCME) in the presence of a hindered base (the DCME reaction) to yield, after oxidation with buffered hydrogen peroxide, the trans-fused bicyclic or cyclic ketone in high enantiomeric excess (ee). In another improved approach, in situ generated IpcBHCl·Et2O, from the reduction of isopinocampheyldichloroborane (IpcBCl2) with trimethylsilane (Me3SiH), in the presence of representative dienes in Et2O provided considerably improved optical yields of the bicyclic and cyclic ketones. The trialkylboranes obtained from suitable acyclic dienes can be easily protonolyzed to provide the secondary alcohols in high ee.
