Enantioselective synthesis of diethyl 1-hydroxyalkylphosphonates via oxazaborolidine catalyzed borane reduction of diethyl α-ketophosphonates
摘要:
Reduction of diethyl alpha-ketophosphonates 1 with borane and B-butyloxazaborolidine 2 as catalyst afforded diethyl (S)- or (R)-1-hydroxyalkylphosphonates 3a-d or 3e-f respectively in good yields and moderate to good enantiomeric excess (53-83 ee%). Respective diethyl (R)- and (S)-1-aminoalkylphosphonates 6 were obtained in a one-pot transformation, by the Mitsunobu reaction of 1-hydroxyphosphonates 3 with hydrazoic acid, and subsequent treatment of the intermediate azides 4, with triphenylphosphine, followed by hydrolysis df the iminophosphoranes 5 with water.
Surface-mediated solid-phase reactions: the preparation of acyl phosphonates by oxidation of 1-hydroxyphosphonates on the solid surface
摘要:
Alumina-supported CrO3, under solvent-free conditions, was found to be an efficient oxidizing reagent for the preparation of acyl phosphonates from 1-hydroxyphosphonates. This method is an easy, rapid, and high-yielding reaction for the preparation of acyl phosphonates from 1-hydroxyphosphonates. (C) 2000 Elsevier Science Ltd. All rights reserved.
Studies on Organophosphorus Compounds, 53: A New Procedure for the Synthesis of 1-Alkyl or 1-Aryl-1-hydroxy-2-nitroethylphoshonates under PTC Conditions
A series of dialkyl 1-alkyl- or 1-aryl-1-hydroxy-2-nitroethyl-phosphonates and 1-hydroxy-1-(nitromethyl)alkylphosphonates was prepared by nucleophilic addition of nitromethane to dialkyl acylphosphonates in the presence of potassium carbonate and tetrabutylammonium bromide.
yielding access to phosphonic γ‐(hydroxyalkyl)butenolides with excellent regio‐, diastereo‐ and enantiocontrol is reported. The simultaneous construction of up to two adjacent quaternary stereogenic centers by a catalytic asymmetric vinylogousMukaiyamaaldolreaction unites biologically and medicinally relevant entities, namely α‐hydroxy phosphonates and γ‐(hydroxyalkyl)butenolides. This is achieved by
A novel route to .alpha.-aminoalkylphosphonic acids and dialkyl .alpha.-aminoalkylphosphonate hydrochlorides
作者:K. Darrell Berlin、N. K. Roy、R. T. Claunch、D. Bude
DOI:10.1021/ja01018a076
日期:1968.7
Catalytic Aldol–Cyclization Cascade of 3-Isothiocyanato Oxindoles with α-Ketophosphonates for the Enantioselective Synthesis of β-Amino-α-hydroxyphosphonates
作者:Satavisha Kayal、Santanu Mukherjee
DOI:10.1021/acs.orglett.5b02929
日期:2015.11.6
A cascade aldol cyclization reaction between 3-isothiocyanato oxindoles and alpha-ketophosphonates has been developed for the synthesis of beta-amino-alpha-hydroxyphosphonate derivatives. Catalyzed by a quinine-based tertiary amino-thiourea derivative, this reaction delivers 2-thioxooxazolidinyl phosphonates based on a spirooxindole scaffold bearing two contiguous quaternary stereogenic centers in high yields with excellent diastereo- (up to >20:1 dr) and enantioselectivities (up to >99:1 er).