Nickel-catalyzed indium(i)-mediated double addition of aldehydes to 1,3-dienes

Abstract

In the presence of InI, Ni(acac)2 and PPh3, several 1,3-dienes were reacted with two molecules of aldehyde to give the corresponding 1,4- and 1,6-diols. The regioselectivity of the 1,4-/1,6-diol was efficiently regulated by the addition of water; the 1,6-diol was obtained selectively in dry THF, whereas the 1,4-diol was obtained predominantly in DMI containing a small amount of water.

Nickel‐Catalyzed Indium(I)‐Mediated syn‐Selective Propargylation of Aldehydes

“…[3] Although the addition of allenyl/ propargylic metals with carbonyl compounds is an extremely powerful method to prepare homopropargylic alcohols, [4] regioselective and stereoselective propargylation mediated by indium has received less attention than In-mediated allylation. [6] We explored a new method for the InI-mediated allylation of carbonyl compounds by using π-allylnickel complexes, where allylic alcohols [7] and dienes [8] serve as good precursors to the allylic reagents. Marshall and co-workers studied the InI-mediated propargylation of carbonyl compounds extensively eventually to produce anti-homopropargylic alcohols with high selectivity.…”

Internal Chelation within Functionalized Organoindium Reagents: Prospects for Regio- and Stereocontrol in the Allylation, Propargylation and Allenylation of Carbonyl Compounds

“…In order to perform a coupling with two different electrophiles, dienyl aldehyde 152 was combined with benzaldehyde under both sets of reaction conditions (Scheme 46). 40 Interestingly, in this case, no effect of water addition on the regioselectivity was observed and 1,6-diol 155 was obtained exclusively under both sets of reaction conditions, albeit noticeable differences in the diastereomer distribution was observed. According to the authors, the much stronger chelation in bicyclic allylindium 153, in comparison to the analogous monocyclic intermediates generated from simple 1,3-dienes, may be preserved even in the presence of water, thus 1,6-diol 155 is obtained exclusively also in aqueous media.…”

“…The idea of regioselectivity control by the addition of water was further applied in the related Ni(0)/InI-mediated tandem allylations of aldehydes with 1,3-diene 147-derived allylindiums (Scheme 45). 40 Similarly to work presented earlier in this review, 38 1,4-diols 150 or 1,6-diols 151 could be obtained regioselectively from the same allylindium precursors, depending on whether DMI with the addition of water or anhydrous THF was applied. According to the authors, addition of the nucleophilic Ni-1,3-diene complex to the first equivalent of aldehyde followed by transmetalation of the resulting -allyl-Ni(II)-intermediate with InI gives a mixture of chelated five-membered allylindium 148 and its linear isomer 149.…”

“…Although the -allylations presented above are interesting from a mechanistic point of view, due to the formation of complex, inseparable mixtures of 1,5-diols, in most cases their applicability in synthesis is low. 39,40 A single example of a more practical Barbier-type -allylation of aldehydes with five-membered chelated allylindiums was reported by Thomas et al 13 Here, intermediate 157 generated from benzyloxyallylstannane 156 via transmetalation with InCl 3 in a reaction with benzaldehyde at ambient temperature delivered the E-configured 1,6-diol 159 in high yield as a mixture of two diastereomers in 70:30 anti/syn ratio, accompanied by only ~5% of the separable Z-substituted isomer (Scheme 47). However, since the use of BiI 3 instead of InCl 3 in this case delivered far better results, further investigation involving allylindiums was abandoned.…”

Stereoselective Borylative Ketone-Diene Coupling

“…While construction of these functional groups is readily accomplished by nucleophilic additions to ketones, such reactions can be challenging, particularly when stereocontrol is a required element . Recent studies in our laboratory have focused on the development of stereoselective borylative aldehyde–diene coupling reactions (Scheme ). − These reactions occur with exceptionally high levels of diastereoinduction when aldehydes are employed as substrates and it was of interest to ascertain whether these processes might also apply to ketone electrophiles and to determine whether high levels of stereocontrol could be maintained . In this report, we show that borylative ketone–diene coupling reactions can be accomplished in high yields and with excellent levels of diastereocontrol.…”