A practical and useful, catalyticenantioselective method has been developed for the synthesis of tertiary diaryl and aryl heteroaryl carbinols starting from commercially available aromatic ketones and aryl or heteroaryl bromides. In this method, organotitanium reagents are generated in situ from the bromides by lithiation with nBuLi followed by transmetallation of the resulting organolithiums with
已经开发了一种实用且有用的催化对映选择性方法,用于从可商购的芳族酮和芳基或杂芳基溴化物开始合成叔二芳基和芳基杂芳基甲醇。在该方法中,通过用n BuLi锂化从溴化物中原位生成有机钛试剂,然后用ClTi(O i Pr)3对所得的有机锂进行金属转移。在(R)-3-(3,5-双三氟甲基苯基)-1,1'-联-2-萘酚(BTFP-BINOL)以高对映选择性和高收率提供了相应的叔醇。反应也可以从呋喃和2-噻吩基锂开始。该方法操作简单,可在10 mmol规模下进行而没有任何困难。
Polymer supported trans-1-phenylsulfonylamino-2-isoborneolsulfonylaminocyclohexane ligand for the titanium catalyzed organozinc addition to ketones
作者:Vicente J. Forrat、Diego J. Ramón、Miguel Yus
DOI:10.1016/j.tetasy.2006.07.038
日期:2006.8
The catalytic enantioselective addition of different organozinc reagents, such as diethylzinc, or in situ generated phenylzinc derivatives to simple ketones was accomplished using titanium tetraisopropoxide and supported chiral ligands derived from trans-1-phenylsulfonylamino-2-isoborneolsulfonylamidocyclohexane, to give the corresponding tertiary alcohols with enantioselectivities up to >99%. A simple
L-Setastine Hydrochloride and Preparation Method Thereof
申请人:Huang Qingyun
公开号:US20140296517A1
公开(公告)日:2014-10-02
The present invention relates to the field of medicine, and disclosed are an L-setastine hydrochloride and a preparation method therefor. The compound of the present invention has the advantages of stronger histamine Hi receptor antagonism and small side effect; the yield of the preparation method is more than 80%, and the product purity is high. The present invention also provides an application of the compound as an H1 histamine receptor antagonist.
A chiral zinc complex of salen was found to be an efficient catalyst for the phenyl transfer of organozinc reagent to aromaticaldehydes and ketones. High enantioselectivities were obtained in reactions of both aromaticaldehydes and ketones (up to 97% and 92% ee, respectively).
A highly efficient enantioselective organozinc (R2Zn) addition to ketones catalyzed by chiral phosphoramide-Zn(II) complexes (1-10 mol %) has been developed. These complexes serve as conjugate Lewis acid-Lewis base catalysts. Chiral phosphoramides are derived from an inexpensive natural amino acid (i.e., L-valine). From a variety of nonactivated aromatic and aliphatic ketones, the corresponding optically