Silylative Kinetic Resolution of Racemic 2,2‐Dialkyl 5‐ and 6‐Membered Cyclic Benzylic Alcohol Derivatives Catalyzed by Chiral Guanidine, (
<i>R</i>
)‐
<i>N</i>
‐Methylbenzoguanidine
作者:Shuhei Yoshimatsu、Kenya Nakata
DOI:10.1002/adsc.201900761
日期:2019.10.22
Efficient silylative kineticresolution of racemic 2,2‐dialkyl 5‐ and 6‐membered cyclic benzylic alcohols was achieved using diphenylmethylchlorosilane (Ph2MeSiCl) or phenyldimethylchlorosilane (PhMe2SiCl) as a silyl source catalyzed by chiral guanidine. The reaction could be applied to a broad range of 2,2‐dialkyl 1‐indanols with good s‐values, irrespective of the electronic nature of the substituent
Silylative Kinetic Resolution of Racemic 1-Indanol Derivatives Catalyzed by Chiral Guanidine
作者:Shuhei Yoshimatsu、Akira Yamada、Kenya Nakata
DOI:10.1021/acs.joc.7b02493
日期:2018.1.5
Efficient kinetic resolution of racemic 1-indanol derivatives was achieved using triphenylchlorosilane by asymmetric silylation in the presence of chiral guanidine catalysts. The chiral guanidine catalyst (R,R)-N-(1-(β-naphthyl)ethyl)benzoguanidine was found to be highly efficient as only 0.5 mol % catalyst loading was sufficient to catalyze the reaction of various substrates with appropriate conversion
The substituenteffect on the solvolysis of 2,2-dimethylindan-1-yl chlorides was analyzed in terms of the LArSR Eq., to give ϱ=−5.81 and r=1.14. The coplanarity of α-t-butylbenzyl cation system was discussed.
Evidence for Spontaneous Cycloaromatization of Nine-Membered Monocyclic Enediyne
作者:Takashi Mita、Shinji Kawata、Masahiro Hirama
DOI:10.1246/cl.1998.959
日期:1998.9
Treatment of 2,2-dimethyl-6-nonene-4,8-diynal (2) with CeCl3/LiN(TMS)2 at −5∼25°C gave 2,2-dimethyl-1-indanol (3) in a moderate yield. In the present study, acyclic (Z)-enediyne aldehyde (2) was cyclized to afford a nine-membered monocyclic enediyne (7), which cycloaromatized spontaneously at room temperature.
The GPR40 receptor function regulator of the present invention, which comprises a compound having an aromatic ring and a group capable of releasing cation is useful as an insulin secretagogue or an agent for the prophylaxis or treatment of diabetes and the like.