A bis(amino)cyclopropenylidene (BAC) catalyzed aza-benzoin reaction between aldehydes and phosphinoyl imines has been developed. The reaction is general with a wide range of aromatic aldehydes and aromatic imines. The reaction displays excellent chemoselectivity favoring aza-benzoin products over homobenzoin products.
Synthesis of N-Diphenylphosphinoylimines Using the Kresze Reaction
摘要:
The synthesis of N-diphenylphosphinoylimines involving the treatment of aldehydes with PP-diphenyl N-sulfinylphosphoramidate (Ph2P(O)NSO) is described. The reagent is prepared from PP-diplienylphosphinic amide, thionyl chloride, and imidazole.
A bis(amino)cyclopropenylidene (BAC) catalyzed aza-benzoin reaction between aldehydes and phosphinoyl imines has been developed. The reaction is general with a wide range of aromatic aldehydes and aromatic imines. The reaction displays excellent chemoselectivity favoring aza-benzoin products over homobenzoin products.
A Three-Component Reaction for the One-Pot Preparation of
β-Amino-α,α-Difluoroketones from Trimethyl(trifluoromethyl)silane (CF3TMS), Acylsilanes and Imines
the acylsilane compared to the imine allows the direct mixing of all the reagents in a three-component, one-pot process. A methodology allowing the direct preparation of β-amino-α,α-difluoroketones from the Ruppert–Prakash reagent (CF3TMS), acyltrimethylsilanes and N-Boc or N-(diphenylphosphinyl)imines is reported. The process, initiated by a catalytic amount of tetra-n-butylammonium difluorotriphenylsilicate
Direct Catalytic Asymmetric Mannich-type Reaction of Hydroxyketone Using a Et<sub>2</sub>Zn/Linked-BINOL Complex: Synthesis of Either <i>a</i><i>nti</i>- or <i>s</i><i>yn</i>-β-Amino Alcohols
Full details of a direct catalyticasymmetric Mannich-type reaction of a hydroxyketone using a Et2Zn/(S,S)-linked-BINOL complex are described. By choosing the proper protective groups on imine nitrogen, either anti- or syn-beta-amino alcohol was obtained in good diastereomeric ratio, yield, and excellent enantiomeric excess using the same zinc catalysis. N-Diphenylphosphinoyl (Dpp) imine 3 gave anti-beta-amino
Enantioselective synthesis of diaryl aziridines using tetrahydrothiophene-based chiral sulfides as organocatalysts
作者:Meng-Ting Huang、Hsin-Yi Wu、Rong-Jie Chein
DOI:10.1039/c3cc47550f
日期:——
This work describes catalytic and asymmetricaziridinations (15 examples, 95-98% ee) of benzyl bromide and imines via the imino Corey-Chaykovsky reaction using (thiolan-2-yl)diarylmethanol benzyl ether as an organocatalyst. The catalyst and analogues thereof were prepared through an expeditious and efficient synthetic route featuring a double nucleophilic substitution and Shi epoxidation as key steps
Catalytic Enantioselective Addition of Dialkylzinc to <i>N</i>-Diphenylphosphinoylimines. A Practical Synthesis of α-Chiral Amines
作者:Alessandro A. Boezio、André B. Charette
DOI:10.1021/ja027673x
日期:2003.2.19
The enantioselectiveaddition of dialkylzincreagents to N-diphenylphosphinoylimines derived from aryl-, furyl-, and cyclopropylaldehydes is efficiently catalyzed by a copper(II) triflate/(R,R)-MeDUPHOS complex. The yields are high (51-98%), and the enantiomeric excesses vary from 85 to 96%. This route provides a practical route to alpha-chiral amines.
Modification of (1R,2S)-1,2-Diphenyl-2-aminoethanol for the Highly Enantioselective, Asymmetric Alkylation ofN-Diphenylphosphinoyl Arylimines with Dialkylzinc
Experimental studies on the modification of (1R,2S)-1,2-diphenyl-2-aminoethanol, which is used to promote the alkylation of N-diphenylphosphinoyl benzalimine with diethylzinc, revealed that N-monosubstituted amino alcohols exhibited higher enantioselectivities than their N,N-disubstituted counterparts and imino alcohols. Application of the optimal chiral ligand 3c to activate the reaction of N-diphenylphosphinoyl