Selective one-pot synthesis of symmetrically and unsymmetrically substituted amines via rhodium catalysed multiple alkylations of ammonia or primary amines under hydroformylation conditions

Catalytic Markovnikov and anti‐Markovnikov Functionalization of Alkenes and Alkynes: Recent Developments and Trends

“…[58] For instance, the dialkylation of ammonia with styrene gave up to 99 % yield with an iso,iso:iso,n ratio of 14:1. [59,60] In a similar reaction to that of ammonia, primary amines are symmetrically dialkylated with two equivalents olefin by using rhodium catalysts such as [Rh(cod) 2 ]BPh 4 and [{RhCl(cod)} 2 ] (Scheme 15; cod is cyclooctadiene). [56] When two equivalents of styrene are used as olefin, tertiary amines with mediocre iso selectivity (iso,iso: iso,n = 2:1) are formed in good yield (80 %).…”

“…The resulting amine reacts then with the slow-forming hydroformylation product of cyclohexene (Scheme 16). [59] a,w-Diamines with long aliphatic chains separating the two amino functions can also be synthesized by carbonylative bishydroaminomethylation of the corresponding a,w-diole-fins together with suitable amines (Scheme 17). [61] Problems of regioselectivity are circumvented by introducing bulky groups in the vicinity of the double bond.…”

Hydroaminomethylation Beyond Carbonylation: Allene–Imine Reductive Coupling by Ruthenium‐Catalyzed Transfer Hydrogenation

“…(1)].Subsequent to Reppes discovery of hydroaminomethylation at BASF in 1949, [2] relatively few studies were disclosed.[3]However,inthe last 15 years,due in large part to the elegant work of Eilbracht, [4] hydroaminomethylation has been intensively investigated [1] and utilized for the preparation of diverse pharmaceutical ingredients, [5] including cinacalcet (Sensipar, Mimpara), [5,6a] ibutilide (Corvert), [5, 6b] and fexofenadine (Allegra, Fexidine,T elfast, Fastofen, Tilfur,V ifas, Te lfexo,A llerfexo). [5,6c] Recent advances in hydroaminomethylation include the use of ammonia as ar eactant, [4c,7] regioselective reactions of terminal [8a] and internal [8b alkenes through ligand control [8] or the use of directing groups, [9] the evolution from rhodium-based to ruthenium-based catalysts, [10] and the emergence of noncarbonylative strategies, including hydroaminoalkylation [11] [Scheme 1, Eq.…”

Highly Selective Synthesis of Enamines from Olefins

“…[11] Notable advances in the last decade have been especially reported by Eilbracht and coworkers, who developed elegant domino variants of hydroaminomethylation reactions. [12] More recently, we presented a rhodium catalyst based on the xantphos ligand (3; Scheme 2), [13] which allowed for the first general, efficient, and highly regioselective (typically n/iso > 98:2) hydroaminomethylation of simple as well as of functionalized a-olefins. [14] During our studies on the improvement of tailor-made catalyst systems for hydroaminomethylations, [15] we noted that the reaction steps of the sequence (1. hydroformylation, 2. imine/enamine formation, 3. hydrogenation) are influenced by the ligand in different ways.…”

“…Indeed, as shown in Table 1 (entries 7, [11][12][13][14], both the chemoselectivity and the regioselectivity (n/iso) [19] of the reaction are controlled by the added ligand. Whereas in the absence of any phosphane ligand essentially no enamine and a nearly 1:1 mixture of linear and iso-amine is formed, the use of the "standard ligand" triphenylphosphane leads to lower conversion (76 %), chemoselectivity (69 %), and regioselectivity (n/ iso = 71:29).…”