73672-36-3Relevant academic research and scientific papers
213. The reductive Conversion of Some Cyclic and Acyclic vic-Epoxides to Alcohols by Means of Lithium Aluminium Hydride/Aluminium Trichloride
Andrejevic, Vladimir,Bjelakovic, Mira,Mihailovic, Milan M.,Mihailovic, Mihailo Lj.
, p. 2030 - 2032 (1985)
Unsubstituted medium-ring 1,2-epoxycycloalkanes and certain vic-epoxyalkanes are reduced to the corresponding alcohols very slowly when LiAlH4 alone is used as reducing agent.However, the combination of LiAlH4 and AlCl3, in a 2:1 molar ratio (with respect to 1 mol-equiv. of epoxide) used in refluxing Et2O, greatly enhances these reductions, rendering them of interest for practical purposes.
A crystalline, internally-coordinated chloroborane for asymmetric hydroboration
von Dollen, Breanna,Wood, John L.,Savage, Quentin R.,Jones, Andrew J.,Garner, Charles M.
supporting information, (2022/02/01)
Asymmetric hydroboration is an important method in the preparation of enantiomerically-enriched compounds that are necessary in many areas of chemistry. Here is reported the preparation of a unique chiral chloroborane-internal ether complex and its applic
Kinetic resolution of racemic allylic alcoholsviairidium-catalyzed asymmetric hydrogenation: scope, synthetic applications and insight into the origin of selectivity
Wu, Haibo,Margarita, Cristiana,Jongcharoenkamol, Jira,Nolan, Mark D.,Singh, Thishana,Andersson, Pher G.
, p. 1937 - 1943 (2021/02/22)
Asymmetric hydrogenation is one of the most commonly used tools in organic synthesis, whereas, kinetic resolutionviaasymmetric hydrogenation is less developed. Herein, we describe the first iridium catalyzed kinetic resolution of a wide range of trisubstituted secondary and tertiary allylic alcohols. Large selectivity factors were observed in most cases (sup to 211), providing the unreacted starting materials in good yield with high levels of enantiopurity (ee up to >99%). The utility of this method is highlighted in the enantioselective formal synthesis of some bioactive natural products including pumiliotoxin A, inthomycin A and B. DFT studies and a selectivity model concerning the origin of selectivity are presented.
Investigation of the Deprotonative Generation and Borylation of Diamine-Ligated α-Lithiated Carbamates and Benzoates by in Situ IR spectroscopy
Mykura, Rory C.,Veth, Simon,Varela, Ana,Dewis, Lydia,Farndon, Joshua J.,Myers, Eddie L.,Aggarwal, Varinder K.
supporting information, p. 14677 - 14686 (2018/11/20)
Diamine-mediated α-deprotonation of O-alkyl carbamates or benzoates with alkyllithium reagents, trapping of the carbanion with organoboron compounds, and 1,2-metalate rearrangement of the resulting boronate complex are the primary steps by which organoboron compounds can be stereoselectively homologated. Although the final step can be easily monitored by 11B NMR spectroscopy, the first two steps, which are typically carried out at cryogenic temperatures, are less well understood owing to the requirement for specialized analytical techniques. Investigation of these steps by in situ IR spectroscopy has provided invaluable data for optimizing the homologation reactions of organoboron compounds. Although the deprotonation of benzoates in noncoordinating solvents is faster than that in ethereal solvents, the deprotonation of carbamates shows the opposite trend, a difference that has its origin in the propensity of carbamates to form inactive parasitic complexes with the diamine-ligated alkyllithium reagent. Borylation of bulky diamine-ligated lithiated species in toluene is extremely slow, owing to the requirement for initial complexation of the oxygen atoms of the diol ligand on boron with the lithium ion prior to boron-lithium exchange. However, ethereal solvent, or very small amounts of THF, facilitate precomplexation through initial displacement of the bulky diamines coordinated to the lithium ion. Comparison of the carbonyl stretching frequencies of boronates derived from pinacol boronic esters with those derived from trialkylboranes suggests that the displaced lithium ion is residing on the pinacol oxygen atoms and the benzoate/carbamate carbonyl group, respectively, explaining, at least in part, the faster 1,2-metalate rearrangements of boronates derived from the trialkylboranes.
