Search results
Results from the WOW.Com Content Network
The pinacol reaction is extremely well-studied and tolerates many different reductants, including electrochemical syntheses.Variants are known for homo- and cross-coupling, intra- and inter-molecular reactions with appropriate diastereo- or enantioselectivity; [2] as of 2006, the only unsettled frontier was enantioselective cross-coupling of aliphatic aldehydes. [3]
Pinacol coupling and the corresponding diamine coupling [1] are possible in the presence of a one-electron reducing agent such as samarium(II) iodide. [ 1 ] Benzylic cations of chromium arene complexes are conformationally stable, and undergo only exo attack to afford S N 1 products stereospecifically, with retention of configuration. [ 1 ]
Akin to pinacol couplings, imines are susceptible to reductive coupling leading to 1,2-diamines. [40] Imine are oxidized with meta-chloroperoxybenzoic acid (mCPBA) to give an oxaziridines. Imines are intermediates in the alkylation of amines with formic acid in the Eschweiler-Clarke reaction.
Pinacol is a branched alcohol which finds use in organic syntheses. It is a diol that has hydroxyl groups on vicinal carbon atoms. A white solid that melts just above room temperature, pinacol is notable for undergoing the pinacol rearrangement in the presence of acid and for being the namesake of the pinacol coupling reaction.
A prominent early synthetic application of organoniobium chemistry was the use of dimethoxyethane niobium trichloride, NbCl 3 (DME), as a reagent for the reductive coupling of imines with carbonyl compounds to form amino alcohols. [9] This reagent has found further use in other pinacol-type reductive couplings. [10] [8]
Six more current or former tennis players linked to a match-fixing syndicate in Belgium were given suspensions of varying lengths — one was barred for 15 years — and fined, the International ...
The A ring closure required two ketone groups for a pinacol coupling which were realized by oxidation of the C11 alcohol (TPAP, NMO) to ketone 36 and Wacker oxidation of the allyl group to diketone 37. After formation of the pinacol product 38 the benzyl groups (sodium, ammonia) and the trialkylsilyl groups (TBAF) were removed to form pentaol 39.
Hints and the solution for today's Wordle on Tuesday, February 4.