H. Piperidine Analogues of Phenyltropanes 967 III. Cocaine Analogues 969 A. Stereoisomers of Cocaine 970 B. Phenyl Ring Substituted Cocaines 970 C. 2â-Substituted Cocaines 973 1. 2â-Substituted Cocaines 973 2. 2â-Substituted 4′-Iodococaines 977 D. N-Modified Cocaines 978 E. 3â-Carbamoyl Analogues of Cocaine 981 F. 3â-Alkylphenyltropanes 982 G. 6/7-Substituted Cocaine and Pseudococaine 982 H. 6-Alkyl-3-benzyltropanes 984 I. Piperidine Homologues of Cocaine 986 IV. 3R-Diphenylmethoxy Tropanes (Benztropine Analogues) 987

Chemistry, design, and structure-activity relationship of cocaine antagonists.

Tamoxifen-poly(ethylene glycol)-thiol gold nanoparticle conjugates: enhanced potency and selective delivery for breast cancer treatment.

The Reformatsky reaction in organic synthesis. Recent advances

A number of different PdII catalyst systems have been reported recently for the Wacker-type aerobic oxidative cyclization of alkenes bearing tethered nitrogen nucleophiles. This study examines the stereochemistry of the aminopalladation step with five different catalyst systems:  Pd(OAc)2/DMSO (A), PdX2/pyridine [X = OAc (B), O2CCF3 (C)], Pd(IMes)(O2CCF3)2(OH2) (D), and Pd(O2CCF3)2/(−)-sparteine (E). Use of a stereospecifically deuterated cyclopentene substrate reveals that four of the five catalyst systems (A, B, C, and E) promote exclusive cis-aminopalladation of the alkene, whereas both cis- and trans-aminopalladation occur with the N-heterocyclic-carbene (NHC) catalyst system. If stoichiometric Bronsted base (NaOAc, Na2CO3) is added to the latter reaction conditions, however, only cis-aminopalladation is observed. The identity of the nitrogen nucleophile also affects the aminopalladation pathway, with results ranging from exclusively cis- to exclusively trans-aminopalladation. These results have impor...

Two-faced reactivity of alkenes: cis- versus trans-aminopalladation in aerobic Pd-catalyzed intramolecular aza-Wacker reactions.

Certain novel 4-substituted N-acylated piperidine derivatives are agonists of the human melanocortin receptor(s) and, in particular, are selective agonists of the human melanocortin-4 receptor (MC-4R). They are therefore useful for the treatment, control, or prevention of diseases and disorders responsive to the activation of MC-4R, such as obesity, diabetes, sexual dysfunction, including erectile dysfunction and female sexual dysfunction.

Acylated piperidine derivatives as melanocortin-4 receptor agonists

A new reagent for the selective, high-yield N-dealkylation of tertiary amines: improved syntheses of naltrexone and nalbuphine

When the economical and easily available 1-chloroalkyl carbonates (RCHClOCO 2 R') are heated neat or in solution with KF in the presence of an 18-crown-6 catalyst, they fragment to aldehydes (RCHO) and fluoroformates (FCO 2 R'). When R in the carbonate reactant is Cl 3 C, the reaction proceeds cleanly without the 18-crown-6 catalyst (Boc-F in 79% yield). This latter variation is most useful on a small industrial scale

A simple conversion of 1-chloroethyl carbonates to fluoroformates: value in the preparation of tertiary alkyl fluoroformates

1,2,2,2-tetrachloroethyl tert-butyl carbonate: a simple and efficient reagent for the tert-butoxycarbonylation of amines and amino acids

In summary, 2,2-dichlorovinyl chloroformate (2a), now prepared for the first time, is stable but also an active acylating agent

2,2-Dichlorovinyl chloroformate

2,2-Dichlorovinyl chloroformate is isolated in 50% distilled yield when chloral is treated with phosgene and zinc dust in 2:1 methyl acetate/ether. The reaction has been extended to other α-chloro and α-bromo aldehydes and ketones in which both other α-positions are occupied by either halo and/or alkyl groups. The reaction fails with hydrogen in an α-position. Similar treatment of α-halo esters gives only the C-acylated products expected from a Reformatsky type reaction, while ketenes are the well-known products from α-halo acid chlorides. However, acyl cyanides and acyl phosphonates, with leaving groups intermediate between fluoride and alkoxide, are converted to chloroformates; e.g., Me 2 C=C(CN)OC(=O)Cl in 67% yield and Me 2 C=C[P(O)(OMe) 2 ]OC(=O)Cl in 83% yield. Carbonates and urethans from these chloroformates are of interest as monomers, pesticides, and chemical intermediates

Jean Pierre Senet

Papers

A new reagent for the selective, high-yield N-dealkylation of tertiary amines: improved syntheses of naltrexone and nalbuphine

A simple conversion of 1-chloroethyl carbonates to fluoroformates: value in the preparation of tertiary alkyl fluoroformates

1,2,2,2-tetrachloroethyl tert-butyl carbonate: a simple and efficient reagent for the tert-butoxycarbonylation of amines and amino acids

2,2-Dichlorovinyl chloroformate

An efficient synthesis of some substituted vinylic chloroformates: reaction scope and limitations