4- Pyridylmagnesium bromide

This chiral N ADH model is prepared by reaction of 3-pyridylmagnesium bromide with menthyl (S)-p-tolylsulfinate (11, 312) to give the sulfoxide 2, which is a precursor to 1. 

An alternative Stille approach was not considered due to concerns about the toxicity of tin, and an attempted Kumada coupling between 2-pyridylmagnesium bromide and 5-iodo-2-chloropyrimidine 991 in the presence of Ni(Cl2)DPPF failed to give the desired product. An attempted Suzuki coupling with 2-bromopyridine 992 also failed, due to the deboronation of 2-chlotopyrimidine-5-boronic acid 993, which gave 2-chloropyrimidine 994 as the... 

The intermediate 2-pyridylmagnesium bromide reacts so fast with sulfoxides that it is trapped only in part by the presence of carbonyl compounds. The slower reactions of the Grignard intermediates from 3- and... 

It should also be noted that these workers transformed the initial bridged palladium complex to a heterobimetallic complex with 2-pyridylmagnesium bromide, which is expected to form the diadamantylated pyridine complex (Scheme 1.50). 

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