Allene Vinyl Halide

In order to obtain a good yield of alkane both r x and rx should be primary alkyl halides.

Allene vinyl halide.

For this reason alkenyl halides with the formula rch chx are sometimes called vinyl halides. The telomerization of allene with allyl and diallylamines yields secondary and tertiary alkadienylamines with up to 85 selectivity. The term vinyl is often used to describe any alkenyl group. The name is derived from the latin word for garlic allium sativum.

The reaction of allene with a lower order silylcuprate 3 leads to an allylsilane vinylcopper intermediate 4 which undergoes palladium catalyzed cross coupling reaction with both vinyl and aryl halides. A detailed discussion of these modifications is beyond the scope of this course but you. An allyl group is a substituent with the structural formula h 2 c ch ch 2 r where r is the rest of the molecule. Aryl or vinylpalladium halide addition to an allene also produces an η 3 allylpalladium halide suitable for amination.

Silver nitrate does not precipitate silver halides in the presence of vinyl halides and this fact was historically used to dispute the existence of the vinyl cation species. Consistent with s n 1 chemistry these reactions follow first order kinetics. Vinyl cations have been observed as reactive intermediates during solvolysis reactions. However the experimental procedure can be modified so that this synthesis can be carried out using a wide range of alkyl aryl vinyl benzyl and allyl halides.