The synthesis of 1-aminobenzylphosphonic acids from benzylidenediphenylmethylamines, for use as structural units in antithrombotic tripeptides
摘要:
Acid hydrolyses of 0,0-dimethyl or 0,0-diethyl 1-(diphenylmethylamino) benzylphosphonate intermediates 2, formed from the addition at elevated temperature of dimethyl or diethyl phosphite to benzylidenediphenylmethylamines 1, generates 1-aminobenzylphosphonic acids 3 in good yield.
Self-assembled organic–inorganic hybrid silica with ionic liquid framework: a novel support for the catalytic enantioselective Strecker reaction of imines using Yb(OTf)3–pybox catalyst
作者:Babak Karimi、Aziz Maleki、Dawood Elhamifar、James H. Clark、Andrew J. Hunt
DOI:10.1039/c0cc01426e
日期:——
Yb(OTf)3âpybox is immobilized in a novel self-assembled ionic liquid hybrid silica and has been successfully applied as a catalyst for the asymmetric Strecker hydrocyanation of aldimines. This catalytic system can be reused for at least 6 times without any significant loss of activity and enantioselectivity.
Catalytic asymmetric Strecker hydrocyanation of imines using Yb(OTf)3–pybox catalysts
作者:Babak Karimi、Aziz Maleki
DOI:10.1039/b908854g
日期:——
We have explored the highly enantioselective Strecker hydrocyanation of a wide range of aromatic, α,β-unsaturated, heterocyclic, and aliphatic aldimines with good to excellent conversions and ees up to 98% in the presence of catalytic amounts of Yb(OTf)3âpybox complexes.
Vaulted Biaryls in Catalysis: A Structure-Activity Relationship Guided Tour of the Immanent Domain of the VANOL Ligand
作者:Yong Guan、Zhensheng Ding、William D. Wulff
DOI:10.1002/chem.201302451
日期:2013.11.11
anion (boroxinate) that is assembled in situ from three equivalents of B(OPh)3 and one of the VANOLligand by a molecule of substrate. The substrates are bound to the boroxinate by H bonds to oxygen atoms O1–O3. The effects of introducing substituents at each position of the naphthalene core of the VANOLligand are systematically investigated in an aziridination reaction. Substituents in the 4,4′‐ and
Described herein are compounds of formula (I), related compositions, and their use, for example in the formation of α-amino acids or a precursor thereof such as an α-aminonitrile.
A practical procedure for catalytic asymmetric synthesis of opticallyactive arylglycine derivatives viaopticallyactive α-aminonitriles has been developed. The N-benzhydryl α-arylaminonitrile intermediates were prepared in excellent yield (89–99%) and enantiomeric purity (96 to >98% ee) by enantioselective cyanation of aldimines with TMSCN/iPrOH in the presence of 2.5 mol % of an easily prepared