Enantioselective organocatalytic α-sulfamidation of aldehydes using sulfonyl azides
作者:Raymond J. McGorry、Stacey K. Allen、Micha D. Pitzen、Thomas C. Coombs
DOI:10.1016/j.tetlet.2017.10.063
日期:2017.12
Enantioselective organocatalytic α-sulfamidation of unbranched aldehydes is described using MacMillan’s second-generation imidazolidinone catalyst and o-nitrobenzenesulfonyl azide. The reactions are highly stereoselective (89.9–96.3% ee) with yields up to 71%. A strong correlation between aldehyde structure and product yield was found to exist, with 3-arylpropanals providing the best results. Application
A new cascade reaction including formal [5 + 2] cycloaddition was developed. Treatment of homocinnamyl alcohol and Co2(CO)6-complexed arylpropynal with BF3·OEt2 resulted in the generation of hydrobenzocycloheptafuran having an alkyne-Co2(CO)6 complex. The reaction consists of 5-membered ring selective Prins cyclization and subsequent Friedel-Crafts cyclization. The cascade reaction was applied to a
A New Organocatalytic Concept for Asymmetric α-Alkylation of Aldehydes
作者:Lorenzo Caruana、Florian Kniep、Tore Kiilerich Johansen、Pernille H. Poulsen、Karl Anker Jørgensen
DOI:10.1021/ja510475n
日期:2014.11.12
The organocatalyticasymmetric α-alkylation of aldehydes by 1,6-conjugated addition of enamines to p-quinone methides is described. Employing a newly developed class of chiral secondary amine catalysts, α-diarylmethine-substituted aldehydes with two contiguous stereocenters have been synthesized in a simple manner with good diastereocontrol and excellent enantioselectivity.
Structure-Guided, Single-Point Modifications in the Phosphinic Dipeptide Structure Yield Highly Potent and Selective Inhibitors of Neutral Aminopeptidases
The constitution of P1′-extended structures was rationally designed and the lead, phosphinic dipeptide hPhePψ[CH2]Phe, was modified in a single position. Introducing a heteroatom/heteroatom-based fragment to either the P1 or P1′ residue required new synthetic pathways. The compounds in the refined structure were low nanomolar and subnanomolar inhibitors of N. meningitides, porcine and human APNs,
The present invention provides a 2,3-dihydro-6-nitroimidazo[2,1-b]oxazole compound represented by the following general formula:
wherein R
1
represents a hydrogen atom or C1-C6 alkyl group, n represents an integer of 0 to 6, R
2
represents a group —OR
3
or the like, and R
3
represents a hydrogen atom, C1-C6 alkyl group or the like, or R
1
and —(CH
2
)
n
R
2
may bind to each other together with carbon atoms adjacent thereto through nitrogen atoms so as to form a spiro ring represented by the general formula (H):
wherein R
41
is hydrogen, C1-C6 alkyl group or the like. The present compound has an excellent bactericidal action against
Mycobacterium tuberculosis
, multi-drug-resistant
Mycobacterium tuberculosis
, and atypical acid-fast bacteria.