Organolithium commercially available

Substituted cyclobutenediones. These useful precursors to quinones (13,209-210) can be prepared from commercially available dialkoxycyclobutenediones (1, dialkyl squarates). Thus a wide variety of organolithium reagents add to 1 at - 78°, and the adducts (a) are hydrolyzed under mild conditions to the cyclobutenediones 2.2 - Protection of a as the /-butyldimethylsilyl ether (b) permits a second addition... 

As a general guide, lithiation by deprotonation using commercially available alkyllithiums is feasible if the new organolithium has at least three stars in the following cumulative scoring system ... 

Other common, and commercially available, organolithium reagents include n-butyllithium and phenyllithium, and they react with both aldehydes and ketones. Note that addition to an aldehyde gives a secondary alcohol while addition to a ketone gives a tertiary alcohol. 

Some Grignard and organolithium reagents are commercially available... 

The commercially available compounds l,2-bis(dichlorophosphino)ethane, 42, and 1,2-bis(dichlorophosphino)benzene will react with organolithiums to give the corresponding bidentate phosphines (Scheme 17).35... 

The synthetic utility of these compounds is based on their easy accessibility from commercially available [Cr(CO)fj] by treatment with an organolithium compound and subsequently with... 

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