175084-95-4Relevant academic research and scientific papers
Facile enantioselective synthesis of a key homoallylic alcohol building block for polyketide synthesis: TiF4-BINOL catalyzed allylsilylation with allyl trimethylsilane
Bode,Gauthier D.R.,Carreira
, p. 2560 - 2561 (2001)
The titanium fluoride-BINOL catalyzed asymmetric allylsilylation of α,α-disubstituted aldehydes provides facile access to highly functionalized, chiral building blocks, which following simple recrystallization affords a key versatile starting material for
Protecting-group-free diastereoselective C-C coupling of 1,3-glycols and allyl acetate through site-selective primary alcohol dehydrogenation
Dechert-Schmitt, Anne-Marie R.,Schmitt, Daniel C.,Krische, Michael J.
supporting information, p. 3195 - 3198 (2013/04/24)
Safe from protection! A pronounced kinetic preference for primary alcohol dehydrogenation enables the site-selective iridium catalyzed C-C coupling of polyols with allyl acetate in the absence of protecting groups, premetallated reagents, chiral auxiliaries, and discrete alcohol-to-aldehyde oxidation.
Enantioselective iridium-catalyzed carbonyl allylation from the alcohol or aldehyde oxidation level via transfer hydrogenative coupling of allyl acetate: Departure from chirally modified allyl metal reagents in carbonyl addition
Kim, In Su,Ngai, Ming-Yu,Krische, Michael J.
supporting information; experimental part, p. 14891 - 14899 (2009/02/08)
Under the conditions of transfer hydrogenation employing an iridium catalyst generated in situ from [Ir(COd)Cl]2, chiral phosphine ligand (R)-BINAP or (R)-Cl,MeO-BIPHEP, and m-nitrobenzoic acid, allyl acetate couples to allylic alcohols 1a-c, aliphatic alcohols 1d-1, and benzylic alcohols 1m-u to furnish products of carbonyl allylation 3a-u with exceptional levels of asymmetric induction. The very same set of optically enriched carbonyl allylation products 3a-u are accessible from enals 2a-c, aliphatic aldehydes 2d-1, and aryl aldehydes 2m-u, using iridium catalysts ligated by (-)-TMBTP or (R)-Cl,MeO-BIPHEP under identical conditions, but employing isopropanol as a hydrogen donor. A catalytically active cyclometallated complex V, which arises upon ortho-C-H insertion of iridium onto m-nitrobenzoic acid, was characterized by single-crystal X-ray diffraction. The results of isotopic labeling are consistent with intervention of symmetric iridium π-allyl intermediates or rapid interconversion of σ-allyl haptomers through the agency of a symmetric π-allyl. Competition experiments demonstrate rapid and reversible hydrogenation-dehydrogenation of the carbonyl partner in advance of C-C coupling. However, the coupling products, which are homoallylic alcohols, experience very little erosion of optical purity by way of redox equilibration under the coupling conditions, although isopropanol, a secondary alcohol, may serve as terminal reductant. A plausible catalytic mechanism accounting for these observations is proposed, along with a stereochemical model that accounts for the observed sense of absolute stereoinduction. This protocol for asymmetric carbonyl allylation transcends the barriers imposed by oxidation level and the use of preformed allyl metal reagents.
Total synthesis of mycalamide A. Further synthetic study of the right half
Nakata, Tadashi,Fukui, Hideto,Nakagawa, Tadakiyo,Matsukura, Hiroko
, p. 159 - 164 (2007/10/02)
The right half 5 of mycalamide A (1) was synthesized starting from (R)- or (S)-pantolactone via the Sharpless asymmetric dihydroxylation as the key step. The total synthesis of mycalamide A (1) was accomplished by coupling of the right and left halves.
