“…There is a broad scope of substrates that have been shown to undergo nucleophilic trifluoromethylation using Ruppert's reagent, and most recently Prakash and co-workers have delved into its reactions with imine derivatives with the idea of developing methods for preparing trifluoromethylamines and, in particular, chiral trifluoromethylamines, , which had previously only been synthesized from precursors (i.e., ketones) already bearing a trifluoromethyl group. − Indeed, use of CF 3 TMS proved to be very effective for nucleophilic trifluoromethylation of N -tosyl aldimines and N -(2-methyl-2-propane-sulfinyl)imines (Scheme ), with the latter reactions exhibiting excellent diastereoselectivity. 1 …”
The nucleophilic trifluoromethylation reagent derived from CF3I and tetrakis(dimethylamino)ethylene (TDAE) was found to be effective in addition to both N-tosyl aldimines and N-tolyl sulfinimines, the latter reaction exhibiting very good diastereoselectivity.
“…There is a broad scope of substrates that have been shown to undergo nucleophilic trifluoromethylation using Ruppert's reagent, and most recently Prakash and co-workers have delved into its reactions with imine derivatives with the idea of developing methods for preparing trifluoromethylamines and, in particular, chiral trifluoromethylamines, , which had previously only been synthesized from precursors (i.e., ketones) already bearing a trifluoromethyl group. − Indeed, use of CF 3 TMS proved to be very effective for nucleophilic trifluoromethylation of N -tosyl aldimines and N -(2-methyl-2-propane-sulfinyl)imines (Scheme ), with the latter reactions exhibiting excellent diastereoselectivity. 1 …”
The nucleophilic trifluoromethylation reagent derived from CF3I and tetrakis(dimethylamino)ethylene (TDAE) was found to be effective in addition to both N-tosyl aldimines and N-tolyl sulfinimines, the latter reaction exhibiting very good diastereoselectivity.
“…Utilization of the homochiral heterocyclic sulfoxide 6 to control the stereochemistry of the desired ( S )-IZD heterocycle was chosen for further investigation for two key reasons. Foremost, Ellman has demonstrated that chiral N - tert -butanesulfinyl imines are substrates for a variety of nucleophiles, providing excellent stereochemical control for these reactions. − We inferred that similar stereochemical control of the hydride delivery to the sulfamide heterocycle 6 could be expected due to the close proximity of olefin to the chiral sulfinamide center. Last, the resulting chiral sulfinamide can easily be converted to the biologically active IZD heterocycle 4 via an oxidation.…”
[structure: see text]. The first asymmetric synthesis of the (S)-1,1-dioxido-isothiazolidin-3-one ((S)-IZD) pTyr mimetic, which has been incorporated into the recently reported potent protein tyrosine phosphatase 1B (PTP1B) inhibitors, is presented herein. The key reaction is the reduction of the (R)-oxido-isothiazolidin-3-one heterocycle with excellent regiochemical and stereochemical control (>98% ee; 82% yield).
The five practical segments for the total synthesis of siomycin A, that is, the dehydropiperidine segment A (5), the pentapeptide segment B (3), the dihydroquinoline segment C (6), and the beta-phenylselenoalanine dipeptide segments D (7) and E (4), were synthesized. Segment A (5) was constructed by the coupling of the azomethine ylide and the chiral sulfinimine, followed by the stereoselective reduction of the six-membered imine function. Segment B (3) was synthesized by the phenylselenylation of the beta-lactone, stereoselective vinylzinc addition to the chiral sulfinimine, and oxazoline-thioamide conversion. Segment C (6) was prepared by the one-pot olefination of the tetrahydroquinoline N-oxide using triflic anhydride and triethylamine, stereoselective reduction of the methyl ketone function, and regioselective Yb(OTf)(3)-catalyzed epoxide opening by the amino group. Segments D (7) and E (4) were synthesized by coupling of the properly protected beta-phenylselenoalanines.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
