Ligands and their preparation

1. A method for preparing a secondary amine (P) comprising reacting a compound (E1) and a primary amine (E2), wherein E1 is a compound of formula (13), E2 is a compound of formula (14) and P is a compound of formula (15):

wherein

X 1 is C, X 2 is N, X 3 is C, and X 4 is N, or

X 1 is N, X 2 is C, X 3 is C, and X 4 is N, or

X 1 is C, X 2 is N, X 3 is N, and X 4 is C, or

X 1 is C, X 2 is C, X 3 is N, and X 4 is N,

wherein C is a carbon atom and N is a nitrogen atom;

V is a leaving group;

R 1 is, identically or differently on each occurrence, H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , B(R 2 ) 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 40 C atoms or a straight-chain alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy, or thioalkoxy group having 3 to 40 C atoms, each of which are optionally substituted by one or more R 2 , wherein one or more non-adjacent CH 2 groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , Ge(R 2 ) 2 , Sn(R 2 ) 2 , C═O, C═S, C═Se, C═NR 2 , P(═O)(R 2 ), SO, SO 2 , NR 2 , O, S, or CONR 2 and wherein one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN, or NO 2 , an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms optionally substituted by one or more R 2 , an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms optionally substituted by one or more R 2 , a diarylamino group, diheteroarylamino group, or arylheteroarylamino group having 10 to 40 aromatic ring atoms optionally substituted by one or more R 2 , or a combination of two or more of these groups; and wherein two or more R 1 optionally define a mono- or polycyclic, aliphatic, aromatic, and/or benzo-fused ring system with one another;

R 2 is, identically or differently on each occurrence, H, D, F, Cl, Br, I, N(R 3 ) 2 , CN, NO 2 , Si(R 3 ) 3 , B(OR 3 ) 2 , C(═O)R 3 , P(═O)(R 3 ) 2 , S(═O)R 3 , S(═O) 2 R 3 , OSO 2 R 3 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 40 C atoms or a straight-chain alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, each of which are optionally substituted by one or more R 3 , wherein one or more non-adjacent CH 2 groups are optionally replaced by R 3 C═CR 3 , C≡C, Si(R 3 ) 2 , Ge(R 3 ) 2 , Sn(R 3 ) 2 , C═O, C═S, C═Se, C═NR 3 , P(═O)(R 3 ), SO, SO 2 , NR 3 , O, S, or CONR 3 and wherein one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN, or NO 2 , an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms optionally substituted by one or more radicals R 3 , an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, optionally substituted by one or more R 3 , a diarylamino group, diheteroarylamino group, or arylheteroarylamino group having 10 to 40 aromatic ring atoms optionally substituted by one or more radicals R 3 , or a combination of two or more of these groups; and wherein two or more adjacent radicals R 2 optionally define a mono- or polycyclic, aliphatic, or aromatic ring system with one another; and

R 3 is, identically or differently on each occurrence, H, D, F, or an aliphatic, aromatic, and/or heteroaromatic hydrocarbon radical having 1 to 20 C atoms, wherein one or more H atoms are optionally replaced by F; and wherein two or more substituents R 3 optionally define a mono- or polycyclic, aliphatic, or aromatic ring system with one another.

2. The method of claim 1 , wherein E1 is a compound of formula (34), E2 is a compound of formula (35), and P is a compound of formula (36):

3. A method for preparing a compound for use as a ligand for metal complexes comprising reacting the compound P of claim 1 with a halide of formula R 1 -Hal to obtain a compound having the following formula:

wherein the reaction is a Buchwald reaction.