Cinchona Alkaloid-Catalyzed Enantioselective Monofluoromethylation Reaction Based on Fluorobis(phenylsulfonyl)methane Chemistry Combined with a Mannich-type Reaction
A catalytic protocol for the unprecedented enantioselectivemonofluoromethylation of in situ generated prochiral imines using 1-fluorobis(phenylsulfonyl)methane (FBSM, 1) in the presence of a chiral PTC based on the Mannich-type reaction followed by reductive desulfonylation has been developed.
作者:Samuel D. Griggs、Nathan Thompson、Daniel T. Tape、Marie Fabre、Paul A. Clarke
DOI:10.1002/chem.201702467
日期:2017.7.12
A general two-stepsynthesis of 2-spiropiperidines has been developed. δ-Amino-β-ketoesters can be reacted with cyclic ketones to generate 2-spiropiperidines in good to excellent yields. The 2-spiropiperidines formed occupy an under-explored region of 3D-chemical space and are novel scaffolds for use in drug discovery programs. These 2-spiropiperidines can be further functionalised to generate small
A novel one-pot, three-component synthesis of N-acyl or N-carbamoyl-alpha-amidosulfides 4 is described. The three-component reaction of aldehydes 1, primary carbamates (or amides) 2 and phenylsulfinic acid (6a) afforded alpha-amidosulfones 7, which after addition of sodium thiolate were in situ transformed into stable alpha-amidosulfides 4 in good to excellent yields. We demonstrated that silver salts
Explorations of an intramolecular route to pyrrolo[3,4-b]isoxazoles: an unexpected retro-Claisen reaction
作者:Raymond C. F. Jones、Carole C. M. Law、Mark R. J. Elsegood
DOI:10.3998/ark.5550190.0014.307
日期:——
Potential precursors have been prepared for intramolecular 1,3-dipolar cycloaddition to form a pyrrolo(3,4-b)isoxazole. The cycloaddition has not to date been accomplished, however an unexpectedretro-Claisenreaction is reported.
Enantioselective Mannich Reaction of β-Keto Esters with Aromatic and Aliphatic Imines Using a Cooperatively Assisted Bifunctional Catalyst
作者:Antti J. Neuvonen、Petri M. Pihko
DOI:10.1021/ol5025025
日期:2014.10.3
An efficient urea-enhanced thiourea catalyst enables the enantioselective Mannichreaction between β-keto esters and N-Boc-protected imines under mild conditions and minimal catalyst loading (1–3 mol %). Aliphatic and aromatic substituents are tolerated on both reaction partners, affording the products in good enantiomeric purity. The corresponding β-amino ketones can readily be accessed via decarboxylation