87100-32-1Relevant articles and documents
Dichloromethyllithium: Synthesis and Application in Continuous Flow Mode
Hafner, Andreas,Mancino, Valentina,Meisenbach, Mark,Schenkel, Berthold,Sedelmeier, Joerg
, p. 786 - 789 (2017)
A simple and robust procedure for the synthesis and use of thermally unstable dichloromethyllithium in continuous flow mode is described. By utilizing residence times in the range of milliseconds for the generation and electrophilic quench of dichlorometh
Homologation of boronic esters to α-chloro boronic esters
Matteson, Donald S.,Majumdar, Debesh
, p. 1529 - 1535 (2008/10/08)
The homologation of boronic esters, RBO2C2R′4 (7), with (dichloromethyl)lithium to form α-chloro boronic esters, R-CHCl-BO2C2R′4 (3), has been found to be a highly efficient process. R may be primary, secondary, or tertiary alkyl, cycloalkyl, alkenyl, allyl, aryl, or benzyl, and functional substituents in R may include α-benzyloxy, β or remote carbalkoxy, or a remote ketal substituent. R′ was H or CH3. The homologation failed in the presence of an α-phenylthio or an α-boronic ester substituent. The α-chloro boronic esters readily undergo nucleophilic replacement of chloride with a variety of reagents, including thiophenolate, benzyl oxide, an ester enolate, or alkyl groups from Grignard or lithium reagents. Either 100% C-alkylation or a majority of O-alkylation and Cope rearrangement could be obtained when tert-butyl lithioacetate reacted with pinacol 3-chloro-1-propene-3-boronate. The β-benzyloxy boronic ester (11) obtained by homologation of pinacol 1-(benzyloxy)pentane-1-boronate (10) decomposed slowly by β boron-oxygen elimination above 100°C but was stable enough to permit replacement of the α-chlorine by methylmagnesium bromide to form 12, which was oxidized with sodium perborate to a mixture of diastereomeric 3-(benzyloxy)-2-heptanols (13).
