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Alkali metal hydridotriphenylborates [(L1)M][HBPh3] (L1=Me6TREN; M=Li, Na, K) chemoselectively catalyze the hydroboration of carbonyls and CO2, with lithium being the most active system. A new series of complexes [(L2)M][HBPh3] [M=Li ( 1), Na ( 2), K ( 3)] featuring the cyclen-derived macrocyclic polyamine Me4TACD (L2) were synthesized in a 'one-pot' fashion and fully characterized including X-ray crystallography. In the crystal, 1- 3 exhibit wide variation in metal coordination of the [HBPh3]− anion from lithium to potassium. The structures differ from those in [(L1)M][HBPh3]. Effects of coordination of L1, L2, and other N- and O-donor multidentate ligands on [Li(HBPh3)] were used to rationalize the catalytic activity in carbonyl hydroboration. [ABSTRACT FROM AUTHOR]

Triphenylborane (BPh3) abstracted the β-SiH in [(L)M{N(SiHMe2)2}] (L = Me6TREN; M = Li, Na, K) in THF to give the hydridotriphenylborates [(L)M][HBPh3]. Reactions in benzene favored silazide instead of hydride abstraction to give [(L)M][Ph3B-N(SiHMe2)2]. The hydridotriphenylborates [(L)M][HBPh3] catalyzed the chemoselective hydroboration of benzophenone by pinacolborane (HBpin), with the lithium derivative being the most active. The solution structure of [(L)Li][HBPh3] was qualitatively investigated in the context of its superior catalytic activity. Fluxional coordination of L in [(L)Li(THF)]+ in tandem with a THF solvent molecule was revealed by NMR spectroscopy. para-Substituents in [HB(C6H4-p-X)3]- influenced the rate which is apparently determined by the addition of the B-H function to the isolable alkoxy borate intermediate [(L)Li][Ph2CHOBPh3]. [ABSTRACT FROM AUTHOR]

The macrocyclic polyamine 1,4,7-trimethyl-1,4,7,10-tetraazacyclododecane [LH = (Me3TACD)H] formed adducts with tetramethyl-silazides [M{N(SiHMe2)2}] (M = Li, Na, K) of light alkali metals. Upon heating, intramolecular dehydrocoupling occurred to give [M{(L)SiMe2N(SiHMe2)}]. BPh3 induced facile ring-opening of THF when reacted with [Li{(L)SiMe2N(SiHMe2)}]. [ABSTRACT FROM AUTHOR]

The macrocyclic polyamine 1,4,7-trimethyl-1,4,7,10-tetraazacyclododecane [LH = (Me3TACD)H] formed adducts with tetramethyl-silazides [M{N(SiHMe2)2}] (M = Li, Na, K) of light alkali metals. Upon heating, intramolecular dehydrocoupling occurred to give [M{(L)SiMe2N(SiHMe2)}]. BPh3 induced facile ring-opening of THF when reacted with [Li{(L)SiMe2N(SiHMe2)}]. [ABSTRACT FROM AUTHOR]

Facile α-H elimination from tetrakis(trimethylsilylmethyl)titanium precursors to give adducts of (alkylidene)bis(alkyl)titanium complexes is induced by light alkali metal amides of the NNNN-type macrocyclic anionic ligand Me 3 TACD [(Me 3 TACD)H=1,4,7-trimethyl-1,4,7,10-tetraazacyclododecane]. In the crystal, the alkali metal interacts with the carbene carbon atom or with the CH 2 group of the trimethylsilymethyl ligand. The nucleophilic character of the carbene carbon atom was shown by the reaction with benzophenone and terminal acetylenes., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A series of light alkali metal organoperoxides [MOOR] (M=Li, Na, K; R=tBu, CMe 2 Ph) were isolated in mononuclear form, aided by the tetradentate and neutral NNNN-type macrocycle Me 4 TACD (L; Me 4 [12]aneN 4 =1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane) and strong hydrogen bonds from additional ROOH molecules. The Na and K compounds are characterized by short O-H⋅⋅⋅O contacts, in the case of the Na derivative as short as 2.41 Å., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Alkali metal hydridotriphenylborates [(L 1 )M][HBPh 3 ] (L 1 =Me 6 TREN; M=Li, Na, K) chemoselectively catalyze the hydroboration of carbonyls and CO 2 , with lithium being the most active system. A new series of complexes [(L 2 )M][HBPh 3 ] [M=Li (1), Na (2), K (3)] featuring the cyclen-derived macrocyclic polyamine Me 4 TACD (L 2 ) were synthesized in a "one-pot" fashion and fully characterized including X-ray crystallography. In the crystal, 1-3 exhibit wide variation in metal coordination of the [HBPh 3 ] - anion from lithium to potassium. The structures differ from those in [(L 1 )M][HBPh 3 ]. Effects of coordination of L 1 , L 2 , and other N- and O-donor multidentate ligands on [Li(HBPh 3 )] were used to rationalize the catalytic activity in carbonyl hydroboration., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)