Starting from the optically pure [6]helicene-like alcohol (P,3S)-3-methyl-4-(4-methylphenyl)-1, 3,6,7-tetrahydrobenzo-[c]benzo [5,6]phenanthro [4,3-e]oxepin-14-ol, four helical phosphites were prepared from the corresponding chlorophosphites. These ligands containing parent or substituted 1,3,2-dioxaphospholan-2-yl or dibenzo [d,f][1,3,2]dioxaphosphepin-6-yl moieties were applied to the asymmetric hydroformylation of terminal alkenes catalyzed by Rh(acac)(CO) 2 and the asymmetric allylic amination of cinnamyl-type carbonates catalyzed by [Ir(cod)Cl] 2 . The helical phosphite containing the dibenzo [d,f][1,3,2]dioxaphosphepin-6-yl group was most successful in the asymmetric hydroformylation of

Please cite this article as: Bojan P.Bondžić, Rh catalyzed multicomponent tandem and one-pot reactions under hydroformylation conditions, Journal of Molecular Catalysis A: Chemical http://dx.

A microflow reaction of the Curtius rearrangement by using trimethylsilyl azide as an azide source, followed by trapping of the generated isocyanate with a nucleophile was established, which is safe, inexpensive, and suitable for largescale synthesis. By this flow reaction in the Curtius re-

Asymmetric epoxidation of α-substituted acroleins with hydrogen peroxide has been catalyzed by diphenylprolinol diphenylmethylsilyl ether to afford α-substituted-β,β-unsubstituted-α,β-epoxy aldehyde with excellent enantioselectivity and the generation of a chiral quaternary carbon center. The method was applied to a short synthesis of (R)-methyl palmoxirate.

Combination of enantioselective allylation reactions with a tandem hydroformylation-Fischer indole synthesis sequence as a highly diversity-oriented strategy for the synthesis of tryptamines and homologues was explored. This modular approach allows the substituents at C3 of the indole core, the type of the amine moiety, and the distance of the amine moiety to the indole core in the final synthetic step to be defined. The starting materials required for the hydroformylation step were synthesized via iridium catalyzed enantioselective allylic substitution reactions in high yields and excellent enantioselectivities. The Rh catalyzed hydroformylation step in the presence of phenyl hydrazine, allows the in situ formed aldehyde to be trapped as the hydrazone. Subsequent acid catalyzed indolization furnishes the desired indole structures in moderate to good yields.

-unsaturated aldehydes have been traditionally used in LUMO lowering asymmetric aminocatalysis (iminium catalysis), while the use of saturated aldehydes as substrates in this type of catalysis has been elusive, until recently. Herein, we demonstrate that organic, single-electron oxidants in the presence of diarylprolinol silylether type catalysts serve as effective tools for the transformation of electron rich enamines to iminium ions which partake in a subsequent Diels-Alder reaction. This enantioselective one-pot transformation represents the first example of saturated aldehydes being used in domino Diels-Alder reaction processes and demonstrates the power of this protocol for construction of stereo-defined chiral compounds and building blocks.

No abstract

No abstract