Kiyoshi Inoguchi

Asymmetric reactions catalyzed by chiral metal complexes: XXXII. Efficient asymmetric hydrogenation of itaconic acid derivatives catalyzed by rhodium complexes of improved (2S,4S)-N-(t-butoxycarbonyl)-4-(diphenylphosphino)-2-[(diphenylphosphino)methyl]pyrrolidine (BPPM) analogues

We have prepared analogues of (2S,4S)-N-(t-butoxycarbonyl)-4-(diphenylphosphino)-2-[(diphenylphsphino)methyl]pyrrolidine (BPPM), bearing para-dimethyl-amino groups to prove the utility of our designing concept with regard to electronic effects of the phosphino groups on the enantioselectivity and the activity of the rhodium complex catalysts. Their rhodium complexes are much more effective than those of BPPM and (2S,4S)-N-(t-butoxycarbonyl)-4-(dicyclohexylphosphino)-2-[(diphenylphosphino)methyl]pyrrolidine (BCPM) for the asymmetric hydrogenation of dimethyl itaconate. The hydrogenation has also been used successfully in an efficient asymmetric synthesis of the key intermediate of new human renin inhibitors.

Synthesis of the bicyclic secondary amines via dimethylaminomethylene ketones from 3-pyrrolidone and 4-piperidone

The reaction of N-protected 3-pyrrolidone and 4-piperidone with N,N-dimethylformamide dimethyl acetal gave the dimethylaminomethylene ketones, which reacted with several types of hydrazines, amidines, and guanidine to afford the secondary amines having fused ring system.

Preparation of newly modified diop bearing bis(4-dimethylamino-3,5-dimethylphenyl)phosphino groups and its application to efficient asymmetric hydrogenation of itaconic acid derivatives

We prepared a modified DIOP analogue bearing bis(4-dimethylamino-3,5-dimethylphenyl)phosphino groups. Its rhodium complex was found to be a useful catalysts for asymmetric hydrogenation of dimethyl itaconate and itaconic acid derivatives bearing β-aryl groups

Design and synthesis of tricyclic tetrahydroquinolines as a new series of nonsteroidal selective androgen receptor modulators (SARMs).

Some tricyclic tetrahydroquinolines (THQs) were found to have the potential of a new series of nonsteroidal selective androgen receptor modulators (SARMs). Compound 5b was first designed and synthesized under our hypothesis based on a four-point pharmacophoric requirement of the 3-carbonyl, 18-methyl, 17-hydroxyl, and 13-quaternary carbon groups of dihydrotestosterone (DHT). It was revealed that this compound exhibits not only a strong androgen receptor (AR) agonistic activity (EC(50)=9.2 nM) but also the highest selectivity in binding affinity to AR among the steroid hormone receptors. Furthermore, this compound showed a weak virilizing effect with retention of the desired anabolic effect as compared with DHT in vivo.

Efficient Preparation of Optically Active (S)-(-)-3-Methyl-γ-butyrolactone by Catalytic Asymmetric Hydrogenation Using Chiral N-Substituted Pyrrolidinebisphosphine Rhodium Complexes

(S)-(-)-2-Methyl succinamic acid, which is a good precursor of (S)-(-)-3-methyl-γ-butyrolactone, can be prepared by homogeneous asymmetric hydrogenation of 2-methylene succinamic acid catalyzed by (2S, 4S)-N-substituted-4-(diphenylphosphino)-2-[(diphenylphosphino)-methyl]pyrrolidine-rhodium complexes. Various N-substituted pyrrolidine-bisphosphines were synthesized to find the optimum ligand for this purpose and to compare the effects of the N-substituents.

Tetrahydroquinolines as a novel series of nonsteroidal selective androgen receptor modulators: structural requirements for better physicochemical and biological properties.

A rationally designed tetrahydroquinoline (1) for nonsteroidal selective androgen receptor modulators was modified for the exploration of promising compounds by Grieco three-component condensation using various dienophiles. Based on the in vitro effects and physicochemical properties of the synthesized compounds, compound 4c was selected for further study. Compound 4c increased the femoral bone mineral density as much as DHT, but it reduced the uterus effect compared with DHT in ovariectomized rats. Thus, compound 4c has desirable osteoanabolic effects with weak undesirable effects on the uterus in a female osteoporosis model.

Novel Series of Highly Potent Non-peptide Growth Hormone Secretagogues with Improved Bioavailability

The discovery and the SAR of acylproline derivatives as highly potent growth hormone secretagogues (GHSs) with good oral bioavailability are described. One representative compound, N-[3-(2,2-dimethylpropylamino)-2-hydroxypropyl]-2(R)-[l-(2,2-dimethylpropionyl)pyrrolidine-2(S)-carbonylamino]-3-naphthalen-2-ylpropionamide (4e), showed potent GHS activity (ED 50 =1 nM) and good oral bioavailability (BA=33.2%). Moreover, the optically pure N-[3-(2,2-dimethylpropylamino)-2(S)-hydroxypropyl]-2(R)-[1-(2,2-dimethylpropionyl)pyrrolidine-2(S)-carbonylamino]-3-naphthalen-2-ylpropionamide ((2S)-4e) showed a good metabolic stability against in vitro clearance (human liver microsome) with potent GHS activity.