1,5-Induction in reactions of 4-alkoxy-2-trimethylsilylalk-2-enyl(tributyl)stannanes with aldehydes

Mn-, Fe-, and Co-Catalyzed Radical Hydrofunctionalizations of Olefins

“…This reaction was discovered before Mukaiyama had realized that silanes bearing a Si–H bond could effect hydration and hydroperoxidation under very mild conditions, and Mukaiyama did not revisit this reaction with silanes or with cobalt complexes bearing simpler ligands. This reaction has seen limited use in synthesis …”

“…This reaction has seen limited use in synthesis. 153 As mentioned previously (Figure 27, section 2.2), Matsushita and co-workers showed in the 1990s that they could convert α,β,γ,δ-unsaturated esters, amides, and nitriles to the corresponding γ-oxo-α,β-unsaturated esters, amides, and nitriles via the intermediacy of a hydroperoxide. 147 This reaction employs Co(tdcpp) in very low catalyst loadings with triethylsilane as reductant and molecular oxygen as oxidant to generate a hydroperoxide, which is subsequently converted to the corresponding γ-oxo-α,β-unsaturated complex in good yield through the action of acetic anhydride and DMAP.…”

Enantioselective Synthesis of 1,5-anti- and 1,5-syn-Diols Using a Highly Diastereoselective One-Pot Double Allylboration Reaction Sequence

“…several groups have described diastereoselective syntheses of 1,5diols and 1,5-amino alcohols via the reactions of aldehydes with structurally complex chiral allylstannane, 4,5 allylsilane, 6 and allyltitanium reagents, 7 no examples currently exist of the type of stereocontrolled, one-pot three-component coupling that we envisaged. We were intrigued by Brown's report that (E)-γ-(1,3,2dioxaborinanyl)allyl]diisopinocampheylborane (4), generated by hydroboration of 2-allenyl-(1,3,2)-dioxaborinane (3) with diisopinocampheylborane [(Ipc) 2 BH], reacts with aldehydes at -78 °C to give 1,2-anti-diols 6 with excellent enantioselectivity via the intermediacy of β-alkoxyallylboronate 5.…”

“…In connection with an ongoing problem in natural products synthesis, we were interested in developing a method for the diastereo- and enantioselective synthesis of 1,5- anti - and 1,5- syn -diols 1 and 2 via the reactions of two different aldehydes, RCHO and RCHO, with a chiral, 1,3-bifunctionalized allylmetal reagent. − This represents a fundamentally interesting problem in organic synthesis, for which practical solutions do not currently exist. While several groups have described diastereoselective syntheses of 1,5-diols and 1,5-amino alcohols via the reactions of aldehydes with structurally complex chiral allylstannane, , allylsilane, and allyltitanium reagents, no examples currently exist of the type of stereocontrolled, one-pot three-component coupling that we envisaged. We were intrigued by Brown's report that ( E )-γ-(1,3,2-dioxaborinanyl)allyl]diisopinocampheylborane ( 4 ), generated by hydroboration of 2-allenyl-(1,3,2)-dioxaborinane ( 3 ) with diisopinocampheylborane [(Ipc) 2 BH], reacts with aldehydes at −78 °C to give 1,2- anti -diols 6 with excellent enantioselectivity via the intermediacy of β-alkoxyallylboronate 5 .…”