Abstract Allylsilanes have been used extensively over the last 30 years. A survey of most recent advances in this field is described, including transformations allylsilanes through electrophilic, radical and organometallic processes. Particular emphasis will be placed on stereocontrol arising from these (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

This review aims to summarize the recent advances in field of Cp*M III (Co, Rh, Ir)‐catalyzed C–H activation followed by subsequent intramolecular reaction. approach has allowed synthesis valuable heterocycles with high structural diversity and complexity, including polycyclic macrocyclic compounds. In this review, a particular attention been made nature coupling partner (alkene, alkyne, etc) its connection either aryl (or vinyl) group or directing group. Hence, different types...

[reaction: see text] Total synthesis of hyacinthacine A(1) and its epimer at C3 is described. The includes a stereocontrolled carboazidation chiral allylsilane as key step. C-Si bond oxidation reduction the azide, with ring-closure, complete total synthesis, which establishes absolute configuration 3.

A novel reaction for the introduction of an azide moiety by means a mild radical process is currently under development. Sulfonyl azides are suitable azidating agents nucleophilic radicals, such as secondary and tertiary alkyl radicals. More electrophilic enolate do not react with sulfonyl azides. This feature allowed development efficient intra- intermolecular carboazidations olefins. Due to versatility azido group, this has important synthetic potential, already demonstrated preparation...

Spirolides are marine toxins that not currently in the routine monitoring assays. Nicotinic receptors seem to be target of these compounds making them a promising pharmacological tool for related diseases as dementias previously shown vitro. In present work, bioavailability 13-desMethyl spirolide C (13-desMeC) brain and vivo effects were tested. Bioavailability was studied by ultra-performance liquid chromatography-mass spectrometry its effect over Alzheimer hallmarks Proton magnetic...

The SF 5 Cl radical addition on unsaturated compounds was performed using an air-stable amine–borane complex as the initiator. This method showed to be complementary classic Et 3 B-mediated alkenes and alkynes. A total of seven alkene three alkyne derivatives were tested in reaction, with yields ranging from 3% 85%.

Abstract The copper‐catalyzed azide alkyne [3+2]‐cycloaddition (CuAAC) reaction of organoboranes represents an attractive area research within the field click chemistry, with diverse applications in organic synthesis, medicinal or materials science. Despite potential issues caused by copper insertion into carbon‐boron bond, significant progress has been made to harness reactivity organoboron compounds CuAAC. This review provides overview catalytic methods reported for CuAAC various...

[reaction: see text] Easily available chiral allylsilanes were used as substrate for carboazidation reactions. For the first time, a substantial control of stereochemistry azidation acyclic nonconjugated radicals was achieved.

The copper-catalyzed asymmetric addition of 2-silyloxyfurans to cyclic unsaturated oxo esters is reported. reaction proceeds with excellent diastereocontrol (usually dr 99:1) and modest high enantioselectivity, depending on the nature ester group substitution ester. We have shown that these substrates can be transformed into a variety building blocks bearing γ-butenolide or γ-lactone connected cycloalkane cycoalkene moiety.

Spiropiperidine derivatives, an important class of bioactive molecules, were synthesized under mild conditions by rhodium(III)-catalyzed intramolecular ArC–H activation. This reaction provides a novel route to highly substituted tricyclic spiropiperidines in good excellent yields. Under acidic the resulting enamines reacted with pendant amides afford derivatives possessing original tetracyclic structure.

Sterically hindered aminoarylboranes featuring atropisomerism about the C-B bond were prepared by addition of organomagnesium species onto readily accessible dialkylamine-borane complexes. Some these aminoarylboranes, isosteres vinyl styrene derivatives, resolved HPLC on chiral stationary phase. They are first examples a non-biaryl type system which display slow rotation bond.

The carboazidation of chiral allylsilanes has been investigated by varying the nature substituents at silicon center and on carbon framework. influence temperature sulfonyl azide, as well stereochemistry remote stereogenic center, 1,2-diastereocontrol process were considered. Good to excellent levels diastereocontrol generally observed, with syn-beta-azidosilane always being formed major isomer. An illustration value this methodology provided a short efficient synthesis an analogue...

Simple models of the spiroimine core (−)-gymnodimine A have been synthesized in racemic and optically active forms. The quaternary carbon spiroimines was created by Michael addition a β-ketoester to acrolein, whereas asymmetric allylic alkylation same used access an enantioselective fashion. Both enantio-enriched mixtures were tested for their biological activities on Xenopusoocytes either expressing (human α4β2) or having incorporated (Torpedo α12βγδ) nicotinic acetylcholine receptors...

Abstract Lewis acid catalyzed vinylogous Mukaiyama–Michael (VMM) reactions between 2‐(trialkylsilyloxy)furans 1 and α,β‐unsaturated cyclic enones 2 or oxo esters 4 have been investigated. Both substrates proved to be useful Michael acceptors in the title reaction, giving butenolides 3 5 good yields. A comparative study as showed better diasterecontrol with latter class of compounds. In both series, crystal structures major isomers revealed anti relationships newly formed stereogenic centers....

1,2-Dispirodienones were synthesized by hypervalent iodine-mediated phenolic oxidation of p-hydroxy acetanilides. The reaction is compatible with several substituted anilides and affords a new class 1,2-dispirodienones that are remarkably stable under thermal or acidic conditions.

Abstract The rhodium(III)‐catalyzed aromatic CH activation/intramolecular Heck‐type reaction has been studied to synthesize spirocyclic compounds, an important class of molecules in medicinal chemistry and natural product synthesis. This approach was efficient with a variety substituted N ‐methoxybenzamides tethered different cyclic alkenes having 5‐, 6‐ or 7‐membered ring. practical method affords sterically hindered o ‐substituted aryl spirocycles that are valuable compounds for further...

Owing to the unusual reactivity of sterically hindered amine-borane complexes, a catalytic system based on magnesium salts was designed perform tandem dehydrogenation-dehydrocoupling between terminal alkynes and boranes. The reaction is providing pure alkynylboranes within few minutes at room temperature, with only two molecules hydrogen as byproduct.

Azepinone derivatives are important frameworks of several natural products and bioactive compounds. They synthetized using a Rh(iii)-catalyzed intramolecular annulation benzamide-tethered allylic alcohols. The reaction requires mild conditions at room temperature affords diversely substituted azepinones bearing quaternary carbon.

A simple procedure has been optimized for the preparation of alkenylaminoborane from alkynes using diisopropylaminoborane and HZrCp2Cl. Coupled with a magnesium-catalyzed dehydrogenation, it allowed use air- moisture-stable diisopropylamine. This synthesis extended to one-pot sequence leading directly bromoalkenes controlled stereochemistry. As such, provides an easy, scalable, cheap process access alkenylboronates both (E)- (Z)-bromoalkenes commercially available alkynes.

The combination of methanesulfonic acid and potassium bifluoride is reported for the deoxyfluorination tertiary alcohols. Under metal-free conditions that use readily available, cheap, easy-to-handle reagents, a range alcohols could be converted into corresponding fluorides in excellent yields (average 85% 23 examples). Mechanistic investigation showed reaction proceeds at 0 °C, part, through an elimination/hydrofluorination pathway, but no residual alkenes are observed. application these...

Atom transfer radical addition of alkyl halides to alkenes was developed using a low amount stable initiator, amine borane complexes. Thanks slow hydroboration step, the overall carbohalogenation process leads good isolated yields.