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
Palladium(0)-catalyzed one-atom ring-expansion of 1-hydroxy-2,2-dialkyl-1-propenoylindan derivatives has been achieved in the presence of P(o-tolyl)(3) giving 2-hydroxy-3,3-dialkyl-2-vinyl-l-tetralone derivatives in excellent yields. This ring-expansion reaction was applied to a 17-(1-oxo-2-propenyl)-beta-estradiol derivative and furnished a similar ring-expanded product in an excellent yield.