Ti‐Catalyzed Hydroamination for the Synthesis of Amine‐Containing π‐Conjugated Materials

Abstract

A series of conjugated enamines were prepared by Ti catalyzed anti-Markovnikov hydroamination. The synthetic route is efficient with yields of up to 94 % and the 100 % atom efficiency of the reaction means that these products are easily isolated and purified. Due to the extended conjugated system, the enamine tautomers were observed exclusively in both solid and solution phases, as determined by X-ray crystallography and NMR spectroscopy. These new conjugated molecules, with N incorporated into the backbone, show interesting photophysical properties including photo-luminescent quantum yields of up to 0.26. Notably, through the incorporation of B to give a donor-acceptor π-conjugated system, a redshift of approximately 100 nm is observed for the emission maximum along with the anticipated solvatochromic shifts.

Hierarchical Core‐Shell N‐Doped Carbon@FeP4‐CoP Arrays as Robust Bifunctional Electrocatalysts for Overall Water Splitting at High Current Density

“…Metal‐organic frameworks (MOF) are self‐assembled crystalline material by metal salts and organic ligands, [ 6 ] constituting ideal precursors for porous carbon‐supported OER catalysts. [ 7 ] These supported catalysts have high active surface area and porous channels, which can shorten electrolyte transport path during electrochemical reactions and display good stability, [ 8 ] including Co@Co 3 O 4 /hollow N‐doped carbon polyhedral, [ 9 ] Co 3 O 4 /N‐doped carbon, [ 10 ] and CoO/CuO@N codoped carbon nanosheet.…”

“…Furthermore, in contrast to test electrodes prepared by bonding catalysts on a glassy carbon electrode, [ 13 ] in situ catalyst growth on porous conductive carriers, [ 14 ] such as nickel foam, carbon cloth, and carbon paper can yield more exposed active sites and/or enhance electrolyte and gas diffusion. [ 6 ]…”

Synthesis of pentasubstituted 2-aryl pyrroles from boryl and stannyl alkynes via one-pot sequential Ti-catalyzed [2 + 2 + 1] pyrrole synthesis/cross coupling reactions

“…Although alkynyl borates exhibited compatibility issues with our catalytic system, a recent report from Schafer has demonstrated a borane-functionalized alkyne as a hydroamination substrate in Ti hydroamination catalysis. 25 Thus, we next examined PhCC-BBN$THF (1a-BBN) ( Table 1, entry 2). Although 1a-BBN gave a low yield of 3a-BBN as the major product, both the heterocoupling selectivity and overall selectivity of the reaction were very high.…”

Using Catalysts To Make Catalysts: Titanium-Catalyzed Hydroamination To Access P,N-Ligands for Assembling Catalysts in One Pot

“…Our group has developed a commercially available diamido-bis­(amidate) Ti alkyne hydroamination precatalyst [Ti] for anti-Markovnikov terminal alkyne hydroamination. − It has good functional group tolerance, and a broad scope of alkynes containing heteroatoms can be used. , Here we show that this catalyst promotes regioselective hydroamination of alkynylphosphines to make P , N -ligands in one atom-economic, catalytic step (Scheme e). The phosphinoenamine/imine product of the hydroamination reaction can be reduced to 2-aminophosphines for isolation, or alternatively these reactive intermediates can be installed directly onto catalytically relevant metal centers using a one-pot approach using salt metathesis reactions.…”