1718-50-9Relevant articles and documents
Synthesis of hydroxyphthioceranic acid using a traceless lithiation-borylation-protodeboronation strategy
Rasappan, Ramesh,Aggarwal, Varinder K.
, p. 810 - 814 (2014)
In planning organic syntheses, disconnections are most often made adjacent to functional groups, which assist in C-C bond formation. For molecules devoid of obvious functional groups this approach presents a problem, and so functionalities must be installed temporarily and then removed. Here we present a traceless strategy for organic synthesis that uses a boronic ester as such a group in a one-pot lithiation-borylation-protodeboronation sequence. To realize this strategy, we developed a methodology for the protodeboronation of alkyl pinacol boronic esters that involves the formation of a boronate complex with a nucleophile followed by oxidation with Mn(OAc) 3 in the presence of the hydrogen-atom donor 4-tert-butylcatechol. Iterative lithiation-borylation- protodeboronation allows the coupling of smaller fragments to build-up long alkyl chains. We employed this strategy in the synthesis of hydroxyphthioceranic acid, a key component of the cell-wall lipid of the virulent Mycobacterium tuberculosis, in just 14 steps (longest linear sequence) with full stereocontrol.
Air-Stable PdI Dimer Enabled Remote Functionalization: Access to Fluorinated 1,1-Diaryl Alkanes with Unprecedented Speed
Kundu, Gourab,Opincal, Filip,Schoenebeck, Franziska,Sperger, Theresa
supporting information, (2021/11/30)
While remote functionalization via chain walking has the potential to enable access to molecules via novel disconnections, such processes require relatively long reaction times and can be in need of elevated temperatures. This work features a remote arylation in less than 10 min reaction time at room temperature over a distance of up to 11 carbons. The unprecedented speed is enabled by the air-stable PdI dimer [Pd(μ-I)(PCy2tBu)]2, which in contrast to its PtBu3 counterpart does not trigger direct coupling at the initiation site, but regioconvergent and chemoselective remote functionalization to yield valuable fluorinated 1,1-diaryl alkanes. Our combined experimental and computational studies rationalize the origins of switchability, which are primarily due to differences in dispersion interactions.
Hydrodecyanation of Secondary Alkyl Nitriles and Malononitriles to Alkanes using DiMeImd-BH3
Kawamoto, Takuji,Oritani, Kyohei,Kawabata, Atsushi,Morioka, Tsubasa,Matsubara, Hiroshi,Kamimura, Akio
, p. 6137 - 6142 (2020/05/22)
The decyanation of secondary aliphatic nitriles and the 2-fold decyanation of malononitriles leading to alkanes in the presence of 1,3-dimethylimidazol-2-ylidene borane (diMeImd-BH3) are reported. These reactions proceed via a radical mechanism that involves the addition of a borane radical to the nitrile to form an iminyl radical, followed by cleavage of a carbon-carbon bond. Theoretical calculations suggest that the β-cleavage of these iminyl radicals, which affords NHC-BH2CN and the corresponding alkyl radicals, is the rate-determining step in this reaction.
Synthesis of Elongated Esters from Alkenes
Miura, Tomoya,Funakoshi, Yuuta,Nakahashi, Junki,Moriyama, Daisuke,Murakami, Masahiro
, p. 15455 - 15459 (2018/10/31)
A convenient method for synthesizing elongated aliphatic esters from alkenes is reported. An (alkoxycarbonyl)methyl radical species is generated upon visible-light irradiation of an ester-stabilized phosphorus ylide in the presence of a photoredox catalyst. This radical species adds onto the carbon–carbon double bond of an alkene to produce an elongated aliphatic ester.
