879224-89-2Relevant academic research and scientific papers
C-H activation by amide chelation control: Ruthenium-catalyzed direct synthesis of 2-Aryl-3-furanamides
Zhao, Yigang,Snieckus, Victor
supporting information, p. 1527 - 1532 (2014/06/09)
A new, catalytic methodology for the synthesis of heterobiaryls by the ruthenium-catalyzed C-H activation/cross-coupling of heterocyclic amides with aryl boroneopentylates is surveyed. From this survey, the highly regioselective reaction of furan-3-carboxamide to give 2-aryl-3-furanamides is optimized and generalized in scope with respect to the aryl boroneopentylate coupling partners. Established thereby is a one-step synthetic method which may supercede the broadly applied two-step directed ortho metalation (DoM)-cross coupling reaction involving cryogenic and strong base conditions and which has potential for further ortho and remote metalation chemistry.
Beyond directed ortho metalation: Ruthenium-catalyzed amide-directed C Ar-N activation/C-C coupling reaction of anthranilamides with organoboronates
Zhao, Yigang,Snieckus, Victor
supporting information, p. 3200 - 3203 (2014/07/08)
A new, catalytic, and general methodology for the synthesis of biaryls and heterobiaryls by the cross coupling of anthranilamide derivatives (o-NMe 2 benzamides) with aryl boroneopentylates is described. The reaction proceeds under catalytic RuH2(CO)(PPh3)3 conditions driven by the activation of the unreactive C-N bond by amide directing group (DG)-Ru catalyst chelation. High regioselectivity, orthogonality with the Suzuki-Miyaura reaction, operational simplicity, and convenient scale-up are features of these reactions which may lend themselves to industrial applications.
Synthesis of enantioenriched tertiary boronic esters by the lithiation/borylation of secondary alkyl benzoates
Pulis, Alexander P.,Blair, Daniel J.,Torres, Eva,Aggarwal, Varinder K.
supporting information, p. 16054 - 16057 (2013/11/19)
Simple, secondary 2,4,6-triisopropyl benzoates (TIB esters) and secondary dialkyl N,N-diisopropyl carbamates have been reported to be resistant to deprotonation by strong bases. We have found that the combination of sBuLi (1.6 equiv) and TMEDA (6 equiv) in CPME at -60 C enables deprotonation of unactivated secondary dialkyl TIB esters, but not the carbamates. These carbanions were reacted with a range of neopentyl boronic esters which, after 1,2-metalate rearrangement and oxidation, gave a range of tertiary alcohols in high yield and universally high er. Further functional group transformations of the tertiary boronic esters were demonstrated (conversion to quaternary centers, C-tertiary amines) together with application of the methodology to the synthesis of the simplest unbranched hydrocarbon bearing a quaternary center, (R)-4-ethyl-4-methyloctane, validating the synthetic utility of the methodology.
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.
