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The diastereoselective nucleophilic trifluoromethylation of a range of ketoamides derived from L-tartaric acid has been studied. TMSCF3 in the presence of a catalytic amount of K2CO3 in DMF has been identified as the conditions leading to the highest diastereoselectivities. A sequential one-pot reaction trifluoromethylation-etherification of the trifluoromethylcarbinol has been developed. Only one further one-pot reaction, ketal hydrolysis-oxidative cleavage, led to the final alpha-trifluoromethylated alpha-alkoxyaldehydes. This procedure was applied to the preparation of a series of enantiopure aryl, heteroaryl, and alkyl alpha-trifluoromethyl-alpha-alkoxyaldehydes.

The development of new fluorine‐containing building blocks and their efficient synthetic access is currently a challenging research field. Herein, the highly regio‐ and stereoselective addition of a large range of aldehydes onto trifluoromethylated benzofulvenes was achieved using a simple La/I2/DIBAL‐Cl system via a selective C−F bond activation process. This versatile methodology provided homodienyl alcohols bearing a terminal CF2‐alkene with potential further applications, as shown by the dehydration to the first benzofulvenes carrying a difluorovinyl group. In addition, for certain electron‐poor aldehydes, unprecedented ipso substitution of the CF3 group in a diene was observed, which, according to DFT studies, is related to the presence of the large, Lewis‐acidic lanthanum metal. [ABSTRACT FROM AUTHOR]

An efficient (+)-camphor-mediated kinetic resolution of racemic cyclohex-2-en-1-ylalane is described. This approach provides an enantiomerically enriched form of the alane, in situ available for synthetic uses. Applied to the allylation of aldehydes, this protocol leads to the corresponding homoallylalcohols in a highly enantioselective manner. [ABSTRACT FROM AUTHOR]

The reaction of low-valent zirconocene reagents formed either from the Negishi reagent Cp2Zr(n-butyl) 2 or from the reduction of Cp2ZrCl2 with Mg with various pentafulvenes yielded the first zirconocene-pentafulvene complexes, Cp2ZrFv (Fv = 6,6-di(aryl), 6,6'-adamantylidene, and 6-tert-butylfulvene), which are formal 20-electron complexes. In addition to NMR spectroscopic analysis and DFT calculations, three complexes were characterized by X-ray crystallography, showing a η5:η¹ dianionic binding mode of the fulvene to the metal. The obtained complexes react with carbonyl compounds (aldehydes and ketones) to unexpectedly afford double-insertion products, as shown by NMR spectroscopy and X-ray studies. In the case of aldehydes these diolate complexes were obtained as single diastereoisomers. The reaction of Cp2ZrFv with internal alkynes did not result in the formation of insertion products but release of the coordinated fulvene and reductive dimerization of the alkynes to the corresponding zirconacyclopentadienes. [ABSTRACT FROM AUTHOR]