Intermolecular hydroaminoalkylation reactions of alkynes with secondary amines, which selectively give access to allylic amines with E configuration of the alkene unit, are achieved in the presence of titanium catalysts. Successful reactions of symmetrically substituted diaryl‐ and dialkylalkynes as well as a terminal alkyne take place with N‐benzylanilines, N‐alkylanilines, and N‐alkylbenzylamines.

The first cationic titanium catalyst system for the intermolecular hydroaminoalkylation of alkenes with various tertiary alkylamines is presented. Corresponding reactions which involve the addition of the a-CÀH bond of a tertiary amine across the CÀC double bond of an alkene take place at temperatures close to room temperature with excellent regioselectivity to deliver the branched products exclusively. Interestingly, for selected amines, a-C À H bond activation occurs not only at N-methyl but also at N-methylene groups.Tertiary amines are important structural motifs in natural products (e.g. alkaloids) and are indispensable for the development of agrochemicals or pharmaceuticals. [1] For example, more than 15 % of the 200 top selling small molecule drugs in 2018 contain a tertiary amine moiety. [1b] An attractive synthetic approach for the synthesis of various amines that has raised a lot of attention in recent years is the hydroaminoalkylation of alkenes which allows the 100 % atom economic addition of the a-C À H bond of simple amines across the C À C double bond of alkenes (Scheme 1). [2] Corresponding addition reactions can be achieved with late transition metal catalysts, [3] following a photo-catalytic approach, [4] or most efficiently with early transition metal catalysts. [5][6][7] In the latter case, neutral group 4 [5] and 5 [6] metal catalysts have extensively been used for a plethora of successful hydroaminoalkylation reactions of alkenes with primary or secondary amines (Scheme 1 a) but unfortunately, tertiary amines do not react successfully with alkenes in the presence of these catalysts. This lack of reactivity must be regarded as a severe restriction to the use of hydroaminoalkylation reactions, because it prohibits the use of simple tertiary amines as starting materials for the synthesis of more sophisticated tertiary amine products. Although a few late transition metal-catalyzed hydroaminoalkylation reactions with tertiary amines have been reported, [3,4] in these cases, the amine must contain an additional metal-binding directing

Intermolecular hydroaminoalkylation reactions of symmetrical and unsymmetrical alkynes with tertiary amines take place in the presence of catalytic amounts of TiBn 4 , Ph 3 C[B(C 6 F 5 ) 4 ], and a sterically demanding aminopyridinato ligand precursor. The resulting products, synthetically and pharmaceutically useful tertiary β,γ-disubstituted allylic amines, are formed in convincing yields and with excellent stereoselectivity. Particularly promising for future applications is the fact that even the industrial side product trimethylamine can be used as a substrate.

The first cationic titanium catalyst system for the intermolecular hydroaminoalkylation of alkenes with various tertiary alkylamines is presented. Corresponding reactions which involve the addition of the a-CÀH bond of a tertiary amine across the CÀC double bond of an alkene take place at temperatures close to room temperature with excellent regioselectivity to deliver the branched products exclusively. Interestingly, for selected amines, a-C À H bond activation occurs not only at N-methyl but also at N-methylene groups.

Hydroaminoalkylation! In this work, the conversion of alkynes into allylic amines within an unbelievably short reaction time of 4 h is presented. In addition to the fast reaction, hydroaminoalkylation is promoted by broad scope, high yields, and excellent stereoselectivity to provide access to synthetically useful products in record time. More information can be found in the Communication by R. Beckhaus, S. Doye, et al. on page 6899.