676593-26-3Relevant academic research and scientific papers
Base-Mediated Radical Borylation of Alkyl Sulfones
Huang, Mingming,Hu, Jiefeng,Krummenacher, Ivo,Friedrich, Alexandra,Braunschweig, Holger,Westcott, Stephen A.,Radius, Udo,Marder, Todd B.
supporting information, (2021/12/02)
A practical and direct method was developed for the production of versatile alkyl boronate esters via transition metal-free borylation of primary and secondary alkyl sulfones. The key to the success of the strategy is the use of bis(neopentyl glycolato) diboron (B2neop2), with a stoichiometric amount of base as a promoter. The practicality and industrial potential of this protocol are highlighted by its wide functional group tolerance, the late-stage modification of complex compounds, no need for further transesterification, and operational simplicity. Radical clock, radical trap experiments, and EPR studies were conducted which show that the borylation process involves radical intermediates.
Recyclable Copper Nanoparticles-Catalyzed Hydroboration of Alkenes and β-Borylation of α,β-Unsaturated Carbonyl Compounds with Bis(Pinacolato)Diboron
Shegavi, Mahadev L.,Saini, Suresh,Bhawar, Ramesh,Vishwantha, Meghana Desai,Bose, Shubhankar Kumar
supporting information, p. 2408 - 2416 (2021/03/16)
Nano-ferrite-supported Cu nanoparticles (Fe-dopamine-Cu NPs) catalyzed anti-Markovnikov-selective hydroboration of alkenes with B2pin2 is reported under mild reaction conditions. This protocol can be applied to a broad range of substrates with high functional group compatibility. In addition, we demonstrated the use of Fe-dopamine-Cu NPs as a catalyst for the β-borylation of α,β-unsaturated ketones and ester, providing alkylboronate esters in up to 98% yield. Reuse of the magnetically recyclable catalyst resulted in no significant loss of activity in up to five reaction runs for both systems. (Figure presented.).
Iron-Based Catalyst for Borylation of Unactivated Alkyl Halides without Using Highly Basic Organometallic Reagents
Siddiqui, Sheema,Bhawar, Ramesh,Geetharani
, p. 1948 - 1954 (2021/01/14)
The mild borylation of alkyl bromides and chlorides with bis(neopentylglycolato)diborane (B2neop2) mediated by iron-bis amide is described. The reaction proceeds with a broad substrate scope and good functional group compatibility. Moreover, sufficient ca
Efficient synthesis of alkylboronic esters: Via magnetically recoverable copper nanoparticle-catalyzed borylation of alkyl chlorides and bromides
Shegavi, Mahadev L.,Agarwal, Abhishek,Bose, Shubhankar Kumar
supporting information, p. 2799 - 2803 (2020/06/17)
We report a magnetically separable Cu nanocatalyst (Fe-DOPA-Cu) for the borylation of alkyl halides with alkoxy diboron reagents, providing alkylboronic esters in high yields, with broad functional group tolerance under mild reaction conditions. The procedure is also applicable to the borylation of benzyl chlorides and bromides. Radical clock experiments support a radical-mediated process. Easy recycling of the catalyst resulted in no significant loss of activity up to ten runs.
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.
4-Cyanopyridine-catalyzed anti-Markovnikov selective hydroboration of alkenes
Xu, Rui,Lu, Guo-Ping,Cai, Chun
supporting information, p. 16456 - 16459 (2018/10/24)
A highly selective anti-Markovnikov hydroboration reaction of alkenes with bis(pinacolato)diboron catalyzed by 4-cyanopyridine has been described. This strategy provides an efficient, practical and environmentally benign protocol for the construction of alkylboronates in moderate to good yields under metal-free conditions. A radical mechanism proceeding via a 4-cyanopyridine-ligated boryl radical was proposed.
Borylation of primary and secondary alkyl bromides catalyzed by Cu2O nanoparticles
Zhou, Xin-Feng,Wu, Ya-Dong,Dai, Jian-Jun,Li, Yong-Jia,Huang, Yu,Xu, Hua-Jian
, p. 46672 - 46676 (2015/06/16)
A Cu2O nanoparticle catalyzed borylation of activated and unactivated alkyl bromides is developed, using bis(pinacolato)diboron as a boron source. To the best of our knowledge this is the first report of a heterogeneous Cu2O nanocata
Ruthenium-catalyzed carbon-carbon bond formation via the cleavage of an unreactive aryl carbon-nitrogen bond in aniline derivatives with organoboronates
Ueno, Satoshi,Chatani, Naoto,Kakiuchi, Fumitoshi
, p. 6098 - 6099 (2008/02/08)
The RuH2(CO)(PPh3)3-catalyzed reaction of 2-amino-6-methylacetophenone with phenylboronic acid 2,2-dimethyl-1,3-propanediol ester in refluxing toluene gave the corresponding phenylation product in 83% yield via aryl carbon
Reagent-controlled asymmetric homologation of boronic esters by enantioenriched main-group chiral carbenoids
Blakemore, Paul R.,Marsden, Stephen P.,Vater, Huw D.
, p. 773 - 776 (2007/10/03)
Putative enantioenriched carbenoid species, (R)-1-chloro-2- phenylethylmagnesium chloride (9) and (S)-1-chloro-2-phenylethyllithium (26), generated in situ by sulfoxide ligand exchange from (-)-(Rs,R)-1- chloro-2-phenylethyl p-tolyl sulfoxide (8), effected the stereocontrolled homologation of boronic esters. sec-Alcohols derived from the product boronates by oxidation with basic hydrogen peroxide exhibited % ee closely approaching that of sulfoxide 8 in examples employing Li-carbenoid 26.
