3-Quinolyl alkanol

On the other hand, (,S )-3-quinolyl alkanol 84 with 94% catalyzes enantioselective isopropylation of quinoline-3-carbaldehyde to give the (,S )-3-quinolyl alkanol 84 itself with 94% 166. The substituent at the 7-position increases the enantiomeric excess to 97% 167. 

Meanwhile, asymmetric autocatalysis of 3-quinolyl alkanol 84-86167,173 and 5-carbamoyl-3-pyridyl alkanol 77174 also proceed with amplification of . Quinolyl alkanols 84 with 9% increases its to 88%173 and the of 5-carbamoyl-3-pyridyl alkanol 77 increased from 14% to 87%174. 

Moreover, when these alkanols with low ee are utilized as asymmetric autocatalysts, 5-pyrimidyl alkanol 28 [48], 3-quinolyl alkanol [49],and 5-carbamoyl-3-pyridyl alkanols [50] with higher ees were obtained. The successive reactions were performed in order to make the best use of the autocatalysis, that is, the products of one round served as the asymmetric autocatalysts for the next. In the case of pyrimidyl alkanol, staring from (S)-alkanol 28a with only 2% ee, the ee reached almost 90% after four rounds [48] without the assistance of any other chiral auxiliary (Scheme 14). 2-Alkynyl-5-pyrimidyl alkanol 28b [5] and 2-... 

Chiral 3-quinolyl alkanol acts as a highly enantioselective asymmetric autocatalyst. Chiral (S)-59 with 94% ee catalyzes the enantioselective addition of i-Pr2Zn to quinoline-3-carbaldehyde (58) to... 

We found that chiral 5-pyrimidyl alkanol, 3-quinolyl alkanol and 5-carbamoyl-3-pyridyl alkanol are highly enantioselective asymmetric autocatalysts for the addition of z-Pr2Zn to the corresponding aldehydes, respectively. Among these, 2-alkynyl-5-pyrimidyl alkanol is a highly efficient asymmetric auto-... 

As described, it took us for 5 years to find pyrimidyl alkanol since the initial asymmetric autocatalysis of pyridyl alkanol of 1990. Soon after pyrimidyl alkanol, we also found efficient systems of asymmetric autocatalysis with 3-quinolyl alkanol [27] and 5-carbamoyl-3-pyridyl alkanol [28]. 

Asymmetric Autocatalysis of Quinolyl Alkanol with Amplification of Enantiopurity... 

As described, pyrimidyl alkanols 2 act as highly efficient asymmetric autocatalysts with significant amplification of chirality. 3-Quinolyl alkanoland 5-carbamoyl-3-pyridyl alkanol also serve as efficient asymmetric autocatalysts with amplification of chirality. 

Scheme 4.18 Resolution of some 2-pyridyl-l -alkanols and quinolyl-lethanols providing the acetates 38-42 and 43, 44, respectively.

After studying various nitrogen-containing compounds, we found that the zinc alkoxide of 2-methyl-l-(3-quinolyl)propan-l-ol 5 (Fig. 1) catalyzes the enantioselective formation of itself with the same configuration in the reaction between quinoline-3-carbaldehyde and z-P Zn to produce the product 5 in high ee (up to 94% ee) [58]. In addition, the 5-carbamoyl-3-pyridyl alkanol 6 (Fig. 1) can act as an efficient autocatalyst to catalyze its own production in a highly enantioselective manner (up to 86% ee) [59]. 

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