TITANIUM COMPOUNDS AND PROCESS FOR CYANATION OF IMINES
申请人:Seayad Abdul Majeed
公开号:US20110319629A1
公开(公告)日:2011-12-29
The present invention relates to titanium catalysts for synthesis reactions produced by bringing a reaction mixture comprising a titanium alkoxide and a ligand in contact with water, wherein the ligand is represented by the general formula (e): wherein R
1
, R
2
, R
3
, and R
4
are independently a hydrogen atom, an alkyl group, or the like, and (A) represents a group with two or more carbon atoms. The titanium catalysts may be isolated in solid form and may be stored. The invention further relates to a process for cyanation of imines, wherein the process comprises reacting an imine with a cyanating agent in the presence of the titanium catalyst.
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.
bisformamides have been shown to catalyze the asymmetric one-pot, three-component Streckerreaction, which produced the α-amino nitriles in excellent yields (up to 99%) with good enantioselectivities (up to 86% ee). Optically pure products could be obtained after a single recrystallization. A possible transition state (TS1) has been proposed to explain the origin of asymmetric inductivity and reactivity according
C 2对称的手性双甲酰胺已显示出催化不对称的一锅,三组分Strecker反应,该反应以优异的对映体选择性(高达86%ee)以优异的收率(高达99%)产生了α-氨基腈。在单次重结晶后可获得光学纯的产物。根据在B3LYP / 6-31G(d)水平下优化的催化剂2a的几何形状和产物4a的绝对构型,已经提出了一种可能的过渡态(TS 1)来解释不对称感应性和反应性的起源。
[EN] TITANIUM COMPOUNDS AND PROCESS FOR CYANATION OF IMINES<br/>[FR] COMPOSÉS DE TITANE ET PROCÉDÉ DE CYANATION DES IMINES
申请人:AGENCY SCIENCE TECH & RES
公开号:WO2010093327A1
公开(公告)日:2010-08-19
The present invention relates to titanium catalysts for synthesis reactions produced by bringing a reaction mixture comprising a titanium alkoxide and a ligand in contact with water, wherein the ligand is represented by the general formula (e), wherein R1, R2, R3, and R4 are independently a hydrogen atom, an alkyl group, or the like, and (A) represents a group with two or more carbon atoms. The titanium catalysts may be isolated in solid form and may be stored. The invention further relates to a process for cyanation of imines, wherein the process comprises reacting an imine with a cyanating agent in the presence of the titanium catalyst.