ABSTRACT
Silacyclic allyl silanes, derived from silene-diene Diels-Alder reactions, combine with acetals in the presence of Lewis acids to afford, following oxidation of the intermediate fluorosilane, either butane-1,4-diols or tetrahydronaphthalenes containing four contiguous chiral centres with moderate to good diastereoselectivity.
Subject(s)
Cyclohexenes/chemistry , Silicones/chemistry , Acetals/chemistry , Crystallography, X-Ray , Cyclohexenes/chemical synthesis , Fluorides/chemistry , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular StructureABSTRACT
The elucidation of a robust and reliable sequence for the generation of highly reactive transient silenes from simple aldehydes is described. The key step involves a silyl-modified Peterson olefination which critically depends on the presence of a sub-stoichiometric amount of soluble lithium salts (LiBr).
Subject(s)
Silene/chemistry , Indicators and Reagents/chemistry , Lithium/chemistry , Magnetic Resonance Spectroscopy , Models, Chemical , Molecular Structure , Solubility , TemperatureABSTRACT
Silenes generated through a silyl-modified Peterson olefination procedure can be trapped with a range of alkyl butadienes via a [4 + 2] cycloaddition pathway to afford silacycles accompanied by variable amounts of competing ene, [2 + 2] and silene dimer by-products. The silacycles are formed with good chemo- and stereo-selectivity and provide access to diols and lactones via a phenyl-triggered Fleming-Tamao oxidation.
Subject(s)
Butadienes/chemistry , Lactones/chemistry , Lactones/chemical synthesis , Silene/chemistry , Silicon/chemistry , Acylation , Magnetic Resonance Spectroscopy , Molecular Structure , StereoisomerismABSTRACT
The simple combination of tris(trimethylsilyl)potassium, ArMgBr, and ArBr provides a novel "one-pot" synthesis of aryl(tristrimethylsilyl)silanes. A mechanistic rationale for this conversion is proposed.