A "stop-and-flow" strategy was developed for the chemoselective dioxygenation of alkenes with a PIFA-initiated cyclization. This method is conceived for the desymmetrization of seco-diene, and a series of substituted 5-hydroxymethyl-γ-lactones were constructed after hydrolysis. This strategy also differentiates terminally substituted alkenes and constitutes a potentially novel synthetic approac...

We report one-pot and chemoselective Knoevenagel-type reactions using highly stable amides and lactams as the electrophilic substrates. The method is based on the in situ activation of amide carbonyl with triflic anhydride and a subsequent reaction with carbanions generated in situ from carbonyl compounds. The amide-based method is an alternative to the versatile thioamide-based Eschenmoser sul...

The coupling of an acyl chloride with an isocyanide affords 2,5-disubstituted oxazoles under mild basic conditions instead of 4,5-disubstituted derivatives when using Schöllkopf conditions (butyllithium); this reaction constitutes a remarkable example of a base-induced chemoselective process in isocyanide chemistry.

The imido-hydrido complex (ArN)Mo(H)(Cl)(PMe(3))(3) catalyses a variety of hydroboration reactions, including the first example of catalytic addition of HBCat to nitriles to form the bis(borylated) amines RCH(2)N(BCat)(2). The latter species easily undergoes chemoselective coupling with aldehydes R'C(O)H to yield imines RCH(2)N=C(H)R'.

The key steps in the synthesis of clavulactone are formation of an enantiopure cyclopentane precursor by epoxide rearrangement and intramolecular carbonyl-ene reaction, construction of the 3,4-dihydro-2H-pyran ring by intermolecular hetero-Diels-Alder reaction, closure of the eleven-membered ring, and finally generation of the lactone functionality by chemoselective allylic C(sp(3))-H oxidation.

The first total synthesis of ganglioside DSG-A (1) is achieved via chemoselective glycosylation and a [1 + 1 + 2] synthetic strategy. We have also developed an efficient method that can be handled on large scale (50 g) for the synthesis of the phytosphingosine.

An efficient and chemoselective cleavage of silyl ethers (primary, secondary and aromatic) by using catalytic quantities of trimethylsilyl bromide (TMSBr) in methanol is reported. A wide range of alkyl silyl ethers such as TBS, TIPS, and TBDPS can be chemoselectively cleaved in high yield in the presence of aryl silyl ethers. The deprotection of silyl esters was also achieved employing catalyti...

Microwave-enhanced, highly efficient protocols for the synthesis of synthetically and biologically important 2,3,6-trisubstituted pyridazine architectures have been developed by sequential amination/Suzuki coupling/alkylation reactions. This powerful strategy is an economical and highly chemoselective protocol for the synthesis of diversified pyridazines. The total synthesis of gabazine (SR-955...

An improved strategy for the synthesis of 2'-O-methyl-guanosine (6) and 2'-MOE-guanosine (8) is reported. The regioselectivity of the alkylation was attained using a novel silicon-based protecting group, methylene-bis (diisopropyl-silylchloride) (MDPSCl2, 2). The alkylation proceeded in a chemoselective manner using NaHMDS as the base and MeCl or MOE-Br as the appropriate electrophiles.

We report a visible-light-induced reductive decarboxylative C(sp(3))-C(sp) bond coupling reaction to construct aryl, alkyl and silyl substituted alkynes at room temperature in organic solvents or neutral aqueous solutions. This chemoselective alkynylation was compatible with various functional groups and biomolecules, and did not affect the protein enzyme activity.