ChemInform Abstract: SYNTHESIS AND REACTIVITY OF 7‐MEMBERED CYCLOPHOSPHOROUS ACIDS WITH AROMATIC SUBSTITUENTS

Abstract

Die wie im Formelschema angegeben zugänglichen cyclischen Phosphorverbindungen (II), (V) bzw. (VII) werden potentiometrisch untersucht.

Synthesis of β-Substituted α-Amino Acids with Use of Iridium-Catalyzed Asymmetric Allylic Substitution

“…Unfortunately, the chemical yield and ee of 8a could not be improved by simply changing the leaving groups of the substrates. To overcome this situation, we next investigated the effect of chiral Ir-ligands 13 − 18 in place of the chiral PTC 11 on the enantioselectivity (Table ). The reaction of 1 with benzoate 4 was carried out in the presence of 50% KOH (3 equiv), [Ir(cod)Cl] 2 (10mol %), and chiral phosphite (20mol %).…”

Diastereoselective Lewis acid mediated hydrophosphonylation of heterocyclic imines: a stereoselective approach towards α-amino phosphonates

“…Accordingly, the minor diastereomer is indicated by 'mi'. The following compounds were synthesized according to known procedures: rac-7λ 5 -dinaphtho[2,3-d:2,3-f][1,3,2]dioxaphosphepin-7-one (= BINOL-phosphonate, 1), 37 5,5-dimethyl-1,3,2λ 5 -dioxaphosphinan-2-one (2a), 38 diisopropyl phosphonate (2b), 39 2,2,5,5tetramethyl-2,5-dihydro-1,3-thiazole (3a), 26 2,2-dimethyl-1thia-4-azaspiro [4.5]dec-3-ene (3b), 26 2,2-dimethyl-1-thia-3azaspiro [4.5]dec-3-ene (3c), 40 7-thia-14-azadispiro[5.1.5.2]pentadec-14-ene (3d), 40 1-thia-4-azaspiro[4.5]dec-3-ene (3e), 41 rac-2,2-dimethyl-5-isopropyl-2,5-dihydro-1,3-thiazole (4), 42 rac-2-phenyl-5,5-dimethyl-2,5-dihydro-1,3-thiazole (5a), 41 rac-2-tert-butyl-5,5-dimethyl-2,5-dihydro-1,3-thiazole (5d), 43 rac-2-tert-butyl-1-thia-3-azaspiro[4.5]dec-3-ene (5e), 44 rac-2isopropyl-1-thia-3-azaspiro [4.5]dec-3-ene (5f). 45 General procedure for the BF 3 -catalyzed hydrophosphonylation of 2,5-dihydro-1,3-thiazoles 3-5 (GP1)…”