Hydroquinidine derivatives

In the same context, an intramolecular Michael reaction involving a nitroalkane as Michael donor and a simple a,p-unsaturated ester as Michael acceptor has been reported using hydroquinidine-derived thiourea 72a as... 

An elecrophilic Br+ or I+ can be successfully transferred to hydroquinidine (13) and two of its commercially available derivatives (4-chlorobenzoate and 9-phenanthryl ether hydroquinidines) simply by mixing two equivalents of the hydroquinidine with one equivalent of sym(co d ne)2-X+ perchlorate in methylene chloride or acetonitrile. H NMR studies (31) showed that the iodonium ion was associated with the nitrogen at the quinuclidine portion of the hydroquinidine instead of the aromatic nitrogen and also that all of the sym-collidines were removed from the X+ since only free collidine and no collidine-I+ peaks were observed. The (hydroquinidine)2-halonium ion is stable in solution for more than 30 minutes at room temperature these ions (and their parent amines) are more soluble in methylene chloride than in acetonitrile, and having R group other than hydrogen also improves the solubility. 

Dihydroquinidine 9-0-(9 -phenanthryl) ether4 (Aldrich, Cat. No. 38195-0 Hydroquinidine 9-phenanthryl ether) gave the highest enantioselectivity compared with several other commercially available dihydroquinidine derivatives 34% ee with dihydroquinidine 4-chlorobenzoate (Aldrich, Cat. No. 33648-3 Hydroquinidine 4-chlorobenzoate) and 61% ee with dihydroquinidine-9-0-(4 -methyl-2 -quinolyl) ether (Aldrich, Cat. No. 38194-2 Hydroquinidine 4-methyl-2-quinolyl ether). The submitters report that the reaction can be run on 0.5-mol scale using this procedure to afford comparable yields and enantiomeric purity of the diol product. 

The quinidine derivative hydroquinidine had some beneficial effects in 10 patients with myotonic dystrophy with slow saccadic eye movements, apathy, and hjrper-somnia (42,43). However, two patients had nausea and epigastric pain and withdrew while taking the active treatment. Although there were no cases of cardiac abnormalities, the authors raised the concern that in patients with myotonic dystrophy, who have a high frequency of cardiac disturbances, the risk of cardiac... 

Chen and coworkers published a formal [3 + 3]-type reaction to give highly substituted cyclohexenes 8. This domino process consists of an allylic-allylic alkylation of an a,a-dicyanoalkene derived from 1-indanone and Morita-Baylis-Hillman carbonates, following an intramolecular Michael addition, by employing dual orga-nocatalysis of commercially available modified cinchona alkaloid (DHQD)2AQN If (hydroquinidine (anthraquinone-l,4-diyl) diether) and (S)-BINOL. The cyclic adducts... 

Skarzewski reacted acyclic enones with thiols catalyzed by cinchona alkaloids [114]. Cinchonine was the best catalyst evaluated and the Michael adducts were obtained in excellent yields albeit with moderate enantioselectivities. Similar approximations were made by Mukaiyama and coworkers using hydroxyl-proUne derivatives, affording the thio adducts in good yields and good enantioselectivities (up to 88% ee) [115], However, the most effective thiol addition to enones was reported by Deng [116]. In this report (DHQD)2PYR (hydroquinidine-2,5-diphenyl-4,6-pyrimidinediyl diether) was used as catalysts, affording the final compounds in excellent yields and enantioselectivities (Scheme 33.37). 

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