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A research presents a highly diastereoselective method for a rhodium catalyzed reductive aldol coupling of vinyl ketones to several [alpha]-amino aldehydes, wherein high levels of syn-aldol selectivity are accompanied by different levels of anti-Felkin-Anh control. The analysis show that the described method helps in the synthesis of aldol stereotriads containing amines, having a control on both relative as well as absolute stereochemistry.

The reductive coupling of conjugated alkynes and iminoacetates that was achieved through catalytic hydrogenation representing the first use of imines as electrophilic partners in simple hydrometallative reductive coupling is discussed. The high levels of relative stereocontrol with respect to the N-sulfinyl moiety allow the absolute stereochemical course of the reductive coupling to be directed.

The well-established intramolecular anion radical chain cyclobutanation reactions are employed as anion radical probes with the Gilman reagent. The species responsible for methylation is probably the contact ion pair (CIP) dimer, while Gilam monomer is responsible for electron transfer that is present in tetrahydrofuran solutions as the solvent separated ion pair.

A study of para-substituted acetophenone-derived bis(enones) reveals that substrate electronic features also direct partitioning of cycloreduction and cycloaddition manifolds. Competitive enone reduction pathways are revealed by the collective experiments.

Research has been conducted on the oligomers encoded with the predetermined assembly modes. The use of the monomeric molecular precursors' hydrogen-bonded tapes in defining the parameters for these oligomers is described.

The use of transition-metal-catalyzed reaction proved to be effective in the creation of a catalyst system that will aid in the synthesis picrotoxane core. Unlike thermal processes, the reaction allows opportunities for the modification of a catalyst to prevent reaction failure. Analysis of bislactone formation reveals that an array of selective transannular cyclizations takes place in relation with ring substitution pattern.

Iridium catalyzed alcohol C-C coupling is used to perform total synthesis of the oxo-polyene macrolide (+)-roxaticin in 20 steps from 1,3-propanediol. The reaction representing the simplest synthesis of any oxo-polyene macrolide could be achieved in the absence of chiral reagents and chiral auxiliaries with minimal use of premetalated C-nucleophiles.

The ortho-cyclometalated [pi]-allyl iridium was used as precatalyst to synthesize products of (trimethylsilyl)allylation with exceptional levels of anti-diastereoselectivity and enantioselectivity in the presence of aldehydes and mediated by 2-propanol. The carbonyl (trimethylsilyl)allylation could also be achieved directly from the alcohol oxidation level to deliver an equivalent set of adducts (trimethylsilyl)allylation with roughly equivalent isolated yields and stereoselectivities in the absence of 2-propanol.

Enantioselective transfer hydrogenation of carbonate in the presence of aromatic, allylic, or aliphatic alcohols using a cyclometalated iridium C,O-benzoate derived from allyl acetate, 4-cyano-3-nitrobenzoic acid and (S)-SEGPHOS has delivered products of (hdroxymethyl)allylation in good anti-diastereoselectivities and enantiocontrol. The studies have represented the first general method for enantioselective carbonyl hydroxymethyl)allylation, a process has does not have any highly stereoselective counterpart in conventional allylmetal chemistry.

5-Substituted-2-furan methanols are subjected to enantioselective carbonyl allylation, crotylation and tert-prenylation after exposing to allyl acetate, [alpha]-methyl allyl acetate, or 1,1-dimethylallene in the presence of an ortho-cyclometalated iridium catalyst modified by (R)-Cl,MeO-BIPHEP, (R)-C3-TUNEPHOS and (R)-C3-SEGPHOS. Optically enriched products of carbonyl allylation, crotylation and reverse prenylation are subjected to Achmatowicz rearrangement for producing the corresponding [gamma]-hydroxy-[beta]-pyrones, with negligible erosion of enantiomeric excess.

Enantioselective transfer hydrogenation of gem-dibenzoate in the presence of aromatic, [alpha],[beta]-unsaturated, or aliphatic aldehydes mediated by isopropyl alcohol and using a cyclometalated iridium C,O-benzoate derived from allyl acetate, 4-cyano-3-nitrobenzoic acid and (R)-SEGPHOS has produced products of alkoxyallylation with good diastereoselectivities and enantioselectivities. This has provided an alternative to the utility of permetalated nucleophiles in carbonyl alkoxyallylation.

ESI-MS, DFT, and synthetic studies were performed to examine the catalytic mechanism of the hydrogen-mediated coupling of acetylene to carbonyl compounds and imines. The collective results from the studies provide new insight into the reactivity of cationic rhodacyclopentadienes, which should facilitate the design of related rhodium-catalyzed C-C couplings.

All-carbon quaternary centers obtained via ruthenium-catalyzed transfer hydrogenation of 2-substituted dienes in the presence of paraformaldehyde which results in reductive coupling at the 2-position to furnish the hydroxymethylation products is reported. The developed method provides an alternative pathway to the hydroformylation of conjugated dienes for which efficient regioselective catalytic systems remain undeveloped.

Enantioselective transfer hydrogenation of 1,1-dimethylallene in the presence of aromatic, [alpha],[beta]-unsaturated, or aliphatic aldehydes mediated by 2-propanol and using a cyclometalated iridium C,O-benzoate derived from allyl acetate, m-nitrobenzoic acid, and (S)-SEGPHOS has delivered reverse-prenylation products in good yields and enantioselectivities. The studies have represented an alternative to the utility of allylmetal reagents in enantioselective carbonyl reverse prenylation and have represented the use of allenes in enantioselective C-C bond-forming transfer hydrogenation.

Ruthenium-catalyzed transfer hydrogenation of N-sulfonamido allene in the presence of aromatic aldehydes, [alpha],[beta]-unsaturated aldehydes and aliphatic aldehydes has resulted in reductive coupling to furnish the corresponding anti-aminoallylation products. This method has provided an alternative to the use of amino-substituted allylborane reagents in carbonyl aminoallylation and has avoided the use of stoichiometric metallic reagents.

The experiments aimed at probing the origins of stereoselection have established a matched mode of ionization for the (R)-acetate and the iridium catalyst modified by (S)-SEGPHOS, as well as reversible ionization of the allylic acetate with rapid [pi]-facial interconversion of the resulting [pi]-crotyl intermediate in advance of C-C bond formation. anti-Diastereo- and enantioselective carbonyl crotylation from the alcohol or aldehyde oxidation level is obtained in the absence of any stoichiometric metallic reagents or stoichiometric metallic byproducts.

A ruthenium catalyzed C-C bond forming transfer hydrogenation is used for the direct vinylation of alcohols or aldehydes by utilizing alkynes as vinyl donors in the absence of any stoichiometric metallic reagents. The development of second generation catalysts for the transformations and the related alcohol-unsaturated C-C couplings are discussed.

Concise stereoselective syntheses of (+-)-quinine and (+-)-7-hydroxyquinine are achieved by using a catalytic enone cycloallylation that has combined the nucleophilic features of the Morita-Baylis-Hillman reaction and the electrophilic features of the Tsuji-Trost reaction. The studies have shown that (+-)-quinine is accessible in 16 steps and 4% overall yield from commercial aminoacetaldehyde diethyl acetal.

A protocol is developed for enantioselective carbonyl allylation from the alcohol or aldehyde oxidation level. This protocol for asymmetric carbonyl allylation has overcome the barriers imposed by oxidation level and the use of preformed allyl metal reagents.

A new reaction mechanism is described where in the formal intermolecular diene hydroacylation is obtained from the alcohol or aldehyde oxidation level via ruthenium-catalyzed C-C bond-forming transfer hydrogenation. The approach is shown to be extremely useful for the synthesis of the [beta],[gamma]-unsaturated ketones.

The first metal catalyzed reductive C-C coupling of vinyl azines is described. A rhodium catalyst ligated by tri-2-furylphosphine is used for achieving modest to high levels of syn-diastereoselectivity.

A new approach for enantioselective iridium-catalyzed carbonyl allylation from the alcohol or aldehyde oxidation is discussed. The method is shown to use allyl acetate as an allyl metal surrogate for better results.

The ruthenium-catalyzed C-C bond forming transfer hydrogenation employing alcohols as the terminal reactants is discussed. The carbonyl allylation from the alcohol or aldehyde oxidation level employing acyclic 1,3-dienes is shown to shown to be instead of the performed allyl metal reagents in the system.

The first enantioselective reductive aldol coupling of vinyl ketones are described, which are achieved through the design of an effective new class of TADDOL-like phosphonite ligands. The studies have shown that organometallics arising transiently in the course of catalytic hydrogenation has offered a byproduct-free alternative to preformed organometallic reagents.

Carbonyl allylation is achieved directly from the alcohol oxidation state via alcohol-allene hydrogen autotransfer. This method is a direct, byproduct-free protocol for carbonyl allylation, while isopropanol is used as a terminal reductant in aldehyde-allene reductive C-C couplings under transfer hydrogenation conditions.

Hydrogenation of alkynes in the presence of carbonyl compounds and imines applying cationic rhodium(I) and iridium(I) precatalysts enables the formation of allylic alcohols and allylic amines. Hydrogenative fragment couplings circumvent the use of preformed organometallic reagents and avoid the generation of stoichiometric byproducts.

The article describes the first asymmetric iridium-catalyzed C-C bond forming hydrogenations, which has enabled the first catalytic enantioselective alkyne-imine reductive couplings. The corresponding allylic amines can be obtained in highly optically enriched form by hydrogenating alkynes in the presence of N-arylsulfonyl imines.