A series of isoquinoline-based chiral diimine ligands are conveniently prepared via Bischler–Napieralski cyclization. The C2-symmetric diimine ligand 1a is effective in Cu(II)-catalyzed enantioselective Henry reactions between nitromethane and various aldehydes (11 examples), showing 50–89% yield and 75–93% ee.(S)-2-(Cyclohexylmethyl)-1-toluenesulfonylaziridineC16H23NO2S[α]D24=-6.4 (c 0.22, CHCl3)Initial source of chirality: (S)-2-amino-3-cyclohexylpropan-1-olAbsolute configuration: (S)(S)-1-Cyclohexyl-3-phenylpropan-2-amineC15H23N[α]D23=+9.7 (c 0.27, CHCl3)Initial source of chirality: (S)-2-amino-3-cyclohexylpropan-1-olAbsolute configuration: (S)N,N′-Bis((S)-1-cyclohexyl-3-phenylpropan-2-yl)oxalamideC32H44N2O2[α]D23=-21.9 (c 0.29, CHCl3)Initial source of chirality: (S)-2-amino-3-cyclohexylpropan-1-olAbsolute configuration: (S,S)(3S,3′S)-3,3′-Bis(cyclohexylmethyl)-3,3′,4,4′-tetrahydro-1,1′-biisoquinolineC32H40N2[α]D23=-12.9 (c 0.37, CHCl3)Initial source of chirality: (S)-2-amino-3-cyclohexylpropan-1-olAbsolute configuration: (3S, 3′S)(R)-3,3-Dimethyl-1-phenylbutan-2-amineC12H19N[α]D22=+48.6 (c 0.88, CHCl3)Initial source of chirality: (S)-2-amino-3,3-dimethylbutan-1-olAbsolute configuration: (R)N, N′- Bis((R)-3,3-dimethyl-1-phenylbutan-2-yl)oxalamideC26H36N2O2[α]D22=36.3 (c 0.54, CHCl3)Initial source of chirality: (S)-2-amino-3,3-dimethylbutan-1-olAbsolute configuration: (R,R)(3R,3′R)-3,3′-Di-tert-butyl-3,3′,4,4′-tetrahydro-1,1′-biisoquinolineC26H32N2[α]D22=+204.8 (c 0.62, CHCl3)Initial source of chirality: (S)-2-amino-3,3-dimethylbutan-1-olAbsolute configuration: (3R, 3′R)Dichloro[(3S,3′S)-3,3′-diisobutyl-3,3′,4,4′-tetrahydro-1,1′-biisoquinoline]-palladium(II)C26H32Cl2N2Pd[α]D23=-702.5 (c 0.43, CHCl3)Initial source of chirality: (S)-2-amino-4-methylpentan-1-olAbsolute configuration: (3R,3′R)(S)-1-(3-Fluorophenyl)-2-nitroethanolC8H26FN2O391% ee[α]D23=+26.8 (c 0.26, CH2Cl2)Initial source of chirality: asymmetric nitroaldol reactionAbsolute configuration: (S)

A series of sterically demanding acyclic aminooxycarbenes (AAOCs) were prepared in good yields from chloroiminium salts and alkoxysilanes via the TMS-Cl elimination pathway. The steric profiles of bulky AAOCs were determined by X-ray crystallographic studies of the Au(I) complexes. The percent buried volume values (%VBur) of the AAOC ligands range from 35.8% to 47.9%. Acyclic aminooxycarbenes maintain coplanarity around the carbene center, in sharp contrast to the similarly bulky acyclic diaminocarbenes that show significant distortion from the coplanarity. The Au(I) complexes of AAOCs exhibited high efficiency in the hydroamination of alkenyl ureas. Bulkier AAOC–Au(I) complexes displayed faster reaction rates and higher conversions. The reaction rate, yield, and stereoselectivity observed with the AAOC–Au(I) catalyst were better than those with acyclic diaminocarbene Au catalysts and comparable to the best results reported to date.

C 1-symmetric isoquinoline-based chiral diaminocarbene ligands (MIQ) have been developed to block three quadrants of the metal coordination sphere, complementing C2-symmetric biisoquinoline-based ligands (BIQ). MIQ-Cu complexes catalyzed conjugate borylation of various α,β-unsaturated amides in good yields (82–99%) and enantioselectivities (75–87% ee).

Sterically demanding and conformationally stable N,N′-ditertiaryalkyl-N,N′-diphenyl acyclic diaminocarbenes (ADCs) were developed. Bulky ADC−Au catalysts not only showed competitive reactivities in hydroamination and enyne cyclization but also demonstrated unique ligand properties different from bulky N-heterocyclic carbene (NHC) counterparts.

2-Alkylpyrrolidines were used as building blocks for acyclic diaminocarbenes (ADCs). First, ureas were made from the corresponding amines, and then the ureas were converted to chloroamidiniums. The chloroamidiniums served as direct precursors to ADCs, and palladium complexes were made utilizing oxidative addition, whereas lithium−halogen exchange was performed to generate rhodium complexes. The carbene ligands were characterized through use of NMR, mass spectrometry, and X-ray analysis, and from X-ray structures, steric parameters were calculated as % VBur values. The ability of these ligands to direct stereochemistry and enhance activity was explored in the Suzuki cross-coupling reaction and the 1,2 addition of arylboronic acids to aldehydes.

A lithium−halogen exchange route has been developed to generate acyclic diaminocarbenes (ADC) from chloroamidinium salts. Convenient access to various ADC complexes (B, Rh, Ir, Pd) stems from a one-pot transmetalation protocol. Formation of a carbenoid species is suggested by 1D and 2D NMR studies with a 13C-labeled chloroamidinium precursor and also by X-ray structures of transition metal−carbene complexes. Rh-ADC complex 4 is an effective catalyst for the 1,2-addition of aryl boronic acids to aryl aldehydes.

A novel acyclic diaminocarbene–copper complex appears to be generated from a chloroamidinium salt and Cu(I)-thiophenecarboxylate in the presence of Grignard reagent based on 13C NMR studies and is a highly efficient catalyst for SN2′-allylic alkylation.

C 1-symmetric isoquinoline-based chiral diaminocarbene ligands (MIQ) have been developed to block three quadrants of the metal coordination sphere, complementing C2-symmetric biisoquinoline-based ligands (BIQ). MIQ-Cu complexes catalyzed conjugate borylation of various α,β-unsaturated amides in good yields (82–99%) and enantioselectivities (75–87% ee).

A novel acyclic diaminocarbene–copper complex appears to be generated from a chloroamidinium salt and Cu(I)-thiophenecarboxylate in the presence of Grignard reagent based on 13C NMR studies and is a highly efficient catalyst for SN2′-allylic alkylation.