Rational Development of Practical Catalysts for Aromatic Carbon−Nitrogen Bond Formation

Simple indole alkaloids and those with a nonrearranged monoterpenoid unit

A series of C2-symmetric chiral quaternary ammonium bromides 10 and 11 have been designed as a new, purely synthetic chiral phase-transfer catalyst, and readily prepared from commercially available optically pure 1,1‘-bi-2-naphthol as a basic chiral unit. The details of the synthetic procedures of each requisite chiral binaphthyl subunit have been disclosed, and the structures of the assembled N-spiro chiral quaternary ammonium bromides 11a and 11f were unequivocally determined by single-crystal X-ray diffraction analysis. The reactivity and selectivity of these chiral ammonium bromides as chiral phase-transfer catalysts have been evaluated in the asymmetric alkylation of the benzophenone Schiff base of glycine ester 7 under mild liquid−liquid phase-transfer conditions, and the optimization of the reaction variables (solvent, base, and temperature) has also been conducted. Further, the scope and limitations of this asymmetric alkylation have been thoroughly investigated with a variety of alkyl halides, in...

Design of N-Spiro C2-Symmetric Chiral Quaternary Ammonium Bromides as Novel Chiral Phase-Transfer Catalysts: Synthesis and Application to Practical Asymmetric Synthesis of α-Amino Acids

Orally-active angiotensin-converting enzyme inhibitors are rapidly establishing themselves in the therapy of hypertension and congestive heart failure. Concerted efforts in a number of laboratories have now led to the discovery or synthesis of an unparalleled variety of potent inhibitors. The manner in which several of these inhibitors bind to ACE is beginning to be understood. It is hoped that some of the insights to be derived from the SAR and structural studies done with ACE inhibitors will be applicable to other enzyme targets as well. The success of ACE inhibitors as pharmacological tools and in the clinic will also quite certainly encourage future efforts to develop new enzyme inhibitor approaches to drug therapy.

Recent developments in the design of angiotensin-converting enzyme inhibitors.

The total synthesis of reserpine

The preparation of a series of 1-glutarylindoline-2(S)-carboxylic acid derivatives, 6a-v and 21a-c, is described The above compounds were tested for inhibition of angiotensin converting enzyme The structure-activity relationship of the series is also discussed Compound 6u, the most potent member of the series, had an in vitro IC50 of 48 X 10(-9) M Compound 6v, an ethyl ester of 6u, lowered blood pressure 70 mm in spontaneous hypertensive rats at an oral dose of 30 mg/kg

Angiotensin converting enzyme inhibitors: 1-glutarylindoline-2-carboxylic acids derivatives.

Reserpine, C33H40O9N2, has been isolated from Rauwolfia serpentina Benth. Reserpine is an ester alkaloid yielding reserpic acid, 3,4,5-trimethoxybenzoic acid and methanol on hydrolysis. Degradation products of reserpic acid make it likely that reserpic acid is a yohimbane derivate, and a hypothetical structure for reserpine has been put forward which is in agreement with the facts known so far.

Charles F. Huebner

Papers

Angiotensin converting enzyme inhibitors: 1-glutarylindoline-2-carboxylic acids derivatives.

Die Konstitution des Reserpins. 8. Mitteilung über Rauwolfia-Alkaloide

Rauwolfia Alkaloids. XIX.1 The Constitution of Deserpidine and Reserpine

Chemistry of rauwolfia alkaloids, including reserpine

N-methyl-n-2-propynyl-l-indanamine. A protent monoamine oxidase inhibitor.