The allene ether version of the Nazarov cyclization was used to construct the cyclopentane dione portion of madindolines A and B. The racemic cyclopentane dione from the Nazarov cyclization was converted to an enol ether that was combined with the chiral, nonracemic hydroxyfuroindoline in a Mannich reaction. Deprotection and oxidation led to (+)-madindoline A and (+)-madindoline B. [reaction: s...

[reaction: see text] One-pot asymmetric Mannich-hydrocyanation reactions are described. Reaction of unmodified aldehydes with N-PMP-protected alpha-imino ethyl glyoxylate in the presence of catalytic amounts of L-proline followed by the addition of Et(2)AlCN provided highly enantiomerically pure beta-cyanohydroxymethyl alpha-amino acid derivatives possessing three contiguous stereogenic centers...

The title benzoxazine molecule, C18H18Br2N2O2, was prepared by a Mannich-type reaction of 4-bromo-phenol with ethane-1,2-di-amine and formaldehyde. The title compound crystallizes in the monoclinic space group C2/c with a centre of inversion located at the mid-point of the C-C bond of the central CH2CH2 spacer. The oxazinic ring adopts a half-chair conformation. The structure is compared to tho...

Inorganic as well as organic base catalysis was found to be effective for diastereoselective Mannich additions of malonic acid derivatives to (SS)-N-(tert-butanesulfinyl)-3,3,3-trifluoroacetaldimine. In the presence of catalytic amounts of inorganic bases, n-BuLi or DMAP, the reaction gives the corresponding (R,SS)-β-aminomalonates in good yield and with diastereoselectivity up to 9/1 dr. In co...

Mannich bases are beta-amino ketone-carrying compounds that the end products of reaction. The reaction is essential in synthesis nitrogen-containing compounds. reaction, a nucleophilic addition forms carbon-carbon bonds, employed numerous natural products, drugs and other There several aminoalkyl chain bearing with high curative value, such as fluoxetine, atropine, ethacrynic acid, trihexypheni...

The easiest route to form compounds with P–Csp3–N linkage(s) is phosphorus-based Mannich-type reactions (phospha-Mannich reactions) between phosphines (R3P, R2PH, RPH2, PH3), carbonyl (mainly CH2O) and amines (R2NH, RNH2, NH3). Because of toxicity inflammability, applications PH3 its liquid analog (Me3Si)3P in such are rare. Stable, less toxic, non-pyrophoric adducts CH2O, i.e., tris(hydroxymet...