Facile alcoholysis of L-lactide catalysed by Group 1 and 2 metal complexes

Alkyl (S)-lactate and alkyl (S,S)-lactyllactate were rapidly and conveniently synthesized from L-lactide using Group 1 and 2 metal complexes as catalyst in alcohol.     

Synthesis of alkylated indolizidine alkaloids via Pummerer mediated cyclization: synthesis of (±)-indolizidine 167B, (±)-5-butylindolizidine and (±)-monomorine I

The syntheses of indolizidine alkaloids, i.e., (±)-coniceine, (±)-indolizidine 167B, (±)-5-butylindolizidine and (±)-monomorine I via Pummerer cyclization are described. The key step is the transformation of lactam sulfoxide to bicyclic lactam via the Pummerer cyclization.     

Nitration‐Oximization of Styrene Derivatives with tert‐Butyl Nitrite: Synthesis of α‐Nitrooximes

A highly efficient method for direct nitration‐oximization of styrene derivatives using tert‐butyl nitrite (t‐BuONO) in DMSO was developed. The present method offers a convenient and practical approach for the synthesis of α‐nitrooximes in moderate to high yields. The salient features entail mild reaction conditions, metal‐free reagent, environmentally benign solvent and simple experimental procedure.     

A stereoselective approach to bioactive secolignans: synthesis of peperomin C and its analogues

A stereoselective approach to secolignans is described. The key synthetic strategy involves an asymmetric aldol reaction to control the creation of the stereogenic center at the β-carbon of the target secolignans. In the present work, peperomin C and its analogues, i.e., 2,6-didehydropeperomin C and 2-epi-peperomin C were successfully synthesized in good yields with high stereoselectivities.     

PhI(OAc)2/KI mediated 1,2-acetoxysulfenylation of alkenes: facile synthesis of β-acetoxysulfides

A convenient method for 1,2-acetoxysulfenylation of alkenes using disulfide promoted by (diacetoxyiodo)benzene (PhI(OAc)₂, DIB)/KI was developed. The reaction is highly regioselective for styrene derivatives while aliphatic alkenes lead to a mixture of two regioisomers.     

Synthesis of high-molecular-weight poly(ε-caprolactone) catalyzed by highly active bis(amidinate) tin(II) complexes

A series of bis(amidinate) tin(II) complexes is synthesized and shown to rapidly polymerize ε-caprolactone (ε-CL) in the presence and absence of benzyl alcohol giving high-molecular-weight poly(ε-CL) (M(n) up to 160,600 Da). Ligands having electron donating groups were found to accelerate the polymerization by making the complex more nucleophilic.     

Difluorophenylsulfanylmethyl radical and difluoromethylene diradical synthons: gem-difluoromethylene building block

Bromodifluorophenylsulfanylmethane has been demonstrated to be a highly versatile gem-difluoromethylene (CF2) building block via the reaction of difluorophenylsulfanylmethyl radical with olefins. gem-Difluoroalkenes and products containing a midchain CF2 group and with manipulatable functionality can be readily synthesized. The first example of a gem-difluoromethylene radical synthon is also reported.     

Anion of 1-[(2-methoxyethoxy)methoxy]-2-phenylsulfonylcyclopropane as a new d3-reagent: preparation of β-substituted α,β-unsaturated aldehydes

Preparation of β-alkylsubstituted α,β-unsaturated aldehydes using a new d³-reagent is described.     

Facile oxidative hydrolysis of acetals to esters using hypervalent iodine(III)/LiBr combination in water

The combination of (diacetoxy)iodobenzene (PhI(OAc)₂, DIB) and lithium bromide (LiBr) efficiently oxidized cyclic and acyclic acetals to the corresponding hydroxyalkyl carboxylic esters and simple esters in good to excellent yields. The merits of this reaction are that it employs commercially available and non-explosive hypervalent iodine(III) reagent, water as the solvent, a short reaction time, and mild reaction conditions.