Regioselective copper-catalyzed alkylation of [2.2.2]-acylnitroso cycloadducts: remarkable effect of the halide of Grignard reagents.

Ring opening with organometallic reagents of [2.2.2]-acylnitroso cycloadducts, including an enantioselective kinetic resolution of these compounds, has been accomplished for the first time.

Nickel-catalyzed borylative ring opening of vinyl epoxides and aziridines.

A mild ring opening of vinyl epoxides and aziridines with B(2)Pin(2) catalyzed by Ni(0)-Binap affords new functionalized allylic boron derivatives which undergo sequential transformations. The uncatalyzed allylation of aldehydes allows obtaining challenging bishomoallylic alicyclic 1,3-diols and 1,3-amino alcohols with remarkably high stereoselectivities. Valuable trans-bisallylic 1,4-amino alcohols can be obtained by a simple oxidation.

Stereoselective synthesis of 4-amino-2,3-unsaturated-N-Cbz-imino-O-glycosides via new diastereoisomeric N-Cbz-imino glycal-derived allyl N-nosyl aziridines.

The glycosylation of alcohols by the new diastereoisomeric d,l-6-deoxy-N-Cbz-imino glycal-derived allyl N-nosyl aziridines 5 and 6 affords, after deprotection of the 4-(N-nosylamino) group, the corresponding 2,3-unsaturated-N-Cbz-imino-O-glycosides bearing a free amino group on C(4) through a completely 1,4-regio- and substrate-dependent stereoselective glycosylation process.

Regio- and stereoselective ring opening of enantiomerically enriched 2-aryl oxetanes and 2-aryl azetidines with aryl borates.

The regioselective ring opening of 2-aryl-substituted four-membered heterocyclic rings with phenols, including catechol, was achieved by the use of aryl borates in mild and neutral reaction conditions without the aid of any transition metal catalysts. While N-alkyl azetidines were found not to be reactive, optically active N-tosyl azetidines gave the corresponding beta-aryloxy amines in a racemic form, thus indicating the considerable carbocationic character of the transition state. The introduction of a hydroxyl group in the azetidine ring (i.

Rhodium-catalyzed enantioselective desymmetrization of bicyclic hydrazines with alkynylboronic esters.

The first successful asymmetric transfer of rhodium-alkynyl species to symmetrical strained alkenes has been realized starting from bicyclic hydrazines and alkynylboronic esters.

Synthesis and cyclodehydration of hydroxyphenols: a new stereoselective approach to 3-aryl-2,3-dihydrobenzofurans.

A novel and simple method for the stereoselective synthesis of substituted 3-aryl-2,3-dihydrobenzofurans by intramolecular cyclization of hydroxyphenols is described. The stereoselective ortho-C-alkylation of phenols allows a novel and stereoselective access to a diverse array of polyfunctionalized products containing a diarylmethane stereogenic center without the need for time-consuming protection-deprotection steps.

Facile regio- and stereoselective carbon-carbon coupling of phenol derivatives with aryl aziridines.

A chemo-, regio-, and stereoselective direct carbon-carbon coupling of readily available aryl borates with N-protected aryl aziridines provides a method for the synthesis of new 2-(o-hydroxyaryl)-2-aryl ethylamines which can be used, in a novel annulation sequence, to give stereodefined substituted 3-aryl indolines. [reaction: see text]

Mild metal-free syn-stereoselective ring opening of activated epoxides and aziridines with aryl borates.

A conceptually new, simple and practical method for the syn-nucleophilic displacement of aryl and vinyl epoxides and aryl aziridines with (substituted) phenols, using aryl borates as activating nucleophiles under neutral conditions, is reported.