71491-60-6

Upstream product

• 505-23-7 1,3 dithiane 
• 930-68-7 cyclohexenone 
• 36049-90-8 2-lithio-1,3-dithiane 
• 3561-67-9 bis(phenylthio)methane 
• 463-58-1 carbon oxide sulfide 
• 74-88-4 methyl iodide 
• 20461-89-6 1,3-dithiane-2-carboxylic acid 

Downstream Products

• 7443-55-2 rac-trans-3-methylcyclohexanol 
• 5454-79-5 cis-3-methylcyclohexanol 

Relevant academic research and scientific papers

Preparation of 2-zincio-l,3-dithianes and di(l,3-dithian-2-yl)zinc and their reaction with highly functionalized halides and a,/?-unsaturated carbonyl compounds

The title compounds were obtained by simple transmetallation of the corresponding lithium derivatives with ZnCl2 or ZnBr2. Contrary to 2-lithio-l,3-dithianes, 2-zincio-l,3-dithianes can react with a number of electrophiles bearing reactive functional grou

Photoredox radical conjugate addition of dithiane-2-carboxylate promoted by an iridium(III) phenyl-tetrazole complex: a formal radical methylation of Michael acceptors

A readily accessible iridium(iii) phenyl-tetrazole complex ([Ir(ptrz)2(tBu-bpy)]+, 2; Hptrz = 2-methyl-5-phenyl-tetrazole; tBu-bpy = 4,4′-di-tert-butyl-2,2′-bipyridine) is shown to be a versatile catalyst for a new photocatalytic Michael reaction. Under light irradiation in the presence of 2, a dithiane 2-carboxylic acid, obtained by simple hydrolysis of a commercially available ethyl ester, generates a 1,3-dithiane radical capable of performing addition to a variety of Michael acceptors (e.g., unsaturated ketones, esters, amides and malonates). This broad scope reaction with high yields is a formal photo-redox addition of the elusive methyl radical and the adducts obtained can be starting materials for a variety of functionalized products. The excited-state oxidation potential of catalyst 2 allows selective formation of radicals only from α-heterosubstituted carboxylates. Chemical modification of this metal complex can tune the electrochemical properties, opening a route to new highly selective catalytic photo-oxidation reactions.

Replacement of HMPA in samarium diiodide promoted cyclizations and reactions of organolithium compounds

Tripyrrolidinophosphoric acid triamide (TPPA) can replace carcinogenic HMPA as a Lewis basic additive in many reactions involving samarium ketyls. In most cases, yields and selectivities of cyclizations of (het)aryl, alkenyl, and alkynyl ketones are simil

Synthesis of new chiral derivatives of N,N′-dimethylpropyleneurea (DMPU) and examination of their influence on the regio- and enantioselectivity of addition of 2-(1,3-dithianyl)lithium to cyclohex-2-en-1-one

The preparation of three new chiral derivatives of DMPU (N,N′-dimethylpropyleneurea) is described (Schemes 2-4); one type of derivative carries 1-phenylethyl or 1-cyclohexylethyl groups at the N-atoms of the tetrahydropyrimidin-2(1H)-one ring (2 and 4), a

Quinuclidine N-oxide: A potential replacement for HMPA

The use of quinuclidine N-oxide as a replacement for HMPA is described.

A Comparison of the Reactions of lithium with α,β-Unsaturated Ketones and Those of Other Acyl Anion Equivalents Containing Sulfur

The factors influencing the site of attack of lithium (1) with enones were investigated.Cyclohexenone (2) was chosen as a model compound, and conjugate addition occurred in THF-HMPA or DME; this mode of addition was also promoted by a potassium counterion.When the reaction was carried out with other enones, conjugate addition in THF-HMPA or DME was only observed if the β-position or the α,β-unsaturated ketone was not disubstituted. 1,4-Addition of 1 could be accomplished by preparation of the cuprate.The use of this approach was illustrated by a preparation of 4,4-dimethylcyclopent-2-en-1-one (28).For determination of the influence of DME on the regiochemical control of the addition of other sulfur-containing anions to enones, the study was extended to the anions derived from 1,3-dithian (29), bis(phenylthio)methane (30), bis(phenylthio)(trimethylsilyl)methane (35), and bis(trimethylsilyl)(phenylthio)methane (36).With these anions, DME did not promote conjugate addition to any significant extent.

A Short Synthesis of the 4-Demethoxy-11-deoxyanthracycline Skeleton. Regiospecific Enolate C-Carboxylation with Carbon Oxysulfide

Regiospecific C-carboxylation of enolate 2 and COS followed by methylation (CH3I) and cuprous triflate cyclization results in a tetracyclic product 9 which can be converted into 11-deoxyanthracyclines.

CONJUGATE (1,4) ADDITION OF HETEROCYCLIC ACYL ANION EQUIVALENTS TO CYCLIC α-ENONES IN THE PRESENCE OF HEXAMETHYLPHOSPHORIC TRIAMIDE: A GENERAL REACTION

Heterocyclic dithiaorganolithium reagents react with cyclic α-enones in THF to yield only products of carbonyl (1,2) addition; in the presence of 2.0 equivalents of hexamethylphosphoric triamide, the addition proceeds to give nearly exclusively the produc

Substitution of HMPT by the Cyclic Urea DMPU as a Cosolvent for Highly Reactive Nucleophiles and Bases

The cyclic urea DMPU (N,N'-dimethyl-N,N'-propylene urea = 1,3-dimethyl-2-oxo-hexahydropyrimidine) is shown to exhibit the same effects as HMPT in oxirane-opening with Li-acetylide, in Wittig olefination, in the double deprotonation of a nitroalkane, in th