Lithium dicyclohexylamide (Cy 2 NLi) reacts with syn-gas or CO to generate transient intermediates with carbene character, which are capable of reacting further with CO or H 2 , effecting sequential C−C and C−H bond formations from CO or H 2 , thus providing a transition-metal-free avenue to the fundamental reactions of the Fischer−Tropsch process. Further experimental and computational data indicate that reactions with CO and H 2 are thermodynamically accessible, with a kinetic bias toward CO homologation.

MP(tBu) (M=Li, Na, K), KH and KN(SiMe ) are shown to activate HD reversibly. In the case of MP(tBu) this leads to isotopic scrambling and the formation of H , D , H(D)P(tBu) and MH(D) in C D . In toluene, KP(tBu) reacts with H but also leads to isotopic scrambling into the methyl groups of the solvent toluene. DFT calculations reveal that these systems effect H activation via cooperative interactions with the Lewis acidic alkali metal and the basic phosphorus, carbanion, or hydride centres, mimicking frustrated Lewis pair (FLP) behaviour.

A series of thirty‐three N,N′‐diaryl, dialkyl, and alkyl‐aryl ureas have been prepared in pyridine or toluene by reaction of silylamines with CO2. This protocol is shown to provide facile access to 13C‐labeled ureas, as well as chiral and macrocyclic ureas. These reactions proceed through initial generation of the corresponding silylcarbamates, which subsequently react with silylamine under thermal conditions to afford the thermodynamically favored urea and disilyl ether.

The Lewis acids Ga(CF), In(CF) and Ga(CCl) are prepared and their Lewis acidity has been probed experimentally and computationally. The species Ga(CF) and In(CF) in conjunction with phosphine donors are shown to heterolytically split H and catalyse the hydrogenation of an imine. In addition, frustrated Lewis pairs (FLPs) derived from Ga(CF) and In(CF) and phosphines react with diphenyldisulfide to phosphoniumgallates or indates of the form [BuPSPh][PhSE(CF)] and [BuPSPh][(μ-SPh)(E(CF))] (E = Ga, In). The potential of the FLPs based on Ga(CF), In(CF) and Ga(CCl) and phosphines is also shown in reactions with phenylacetylene to give pure or mixtures of the products [BuPH][PhCCE(CX)] and RP(Ph)C=C(H)E(CX) A number of these species are crystallographically characterized. The implications for the use of these species in FLP chemistry are considered.This article is part of the themed issue 'Frustrated Lewis pair chemistry'.

The indium compounds In(N(SiMe ) ) Cl⋅THF (2) and In(N(SiMe ) )Cl ⋅(THF) (3) were shown to react with CO to give [(Me Si) N)InX(μ-OSiMe )] (X=N(SiMe ) 4, Cl 5). 0.05-2.0 mol % of the species 3 acts as a pre-catalyst for the conversion of aryl and alkyl silylamines under CO (2-3 atm) to give the corresponding ureas in 70-99 % yields. A proposed mechanism is supported by experimental and computational data.

The analogy of the reactivity of group 1phosphides to that of FLPs is further demonstrated by reactions with CO, affording anew synthetic route to acyl-phosphide anions.The reaction of [K(18-crown-6)][PtBu 2 ](1)with CO affords [(18crown-6)K·THF 2 ][Z-tBuP=C(tBu)O] (2·THF 2 )a st he major product, and the minor product [K 6 (18-crown-6)]-[(tBu 2 PCO) 2 ] 3 (3). Species 2 reacts with either BPh 3 or additional CO to give [K(18-crown-6)][(Ph 3 B)tBuPC(tBu)O] (4)a nd [K(18-crown-6)][(OCtBu) 2 P] (5), respectively.T he acyl-phosphide anion 2 is thought to be formed by ap hotochemically induced radical process involving at ransient species with triplet carbene character,p rompting 1,2-tertbutyl group migration. As imilar process is proposed for the subsequent reaction of 2 with CO to give 5.

We report two organocatalysts for CO2 hydroboration to methylborylethers, which upon hydrolysis can produce methanol. These organocatalysts feature carbon-centered reversible CO2 binding, broad borane scopes, and high catalytic activities.

The reaction of K[N(SiMe 3 ) 2 ] with 13 CO proceeds in C 6 D 6 or THF affording K 13 CN and O(SiMe 3 ) 2 under mild conditions as confirmed by crystallographic characterization of K(18-crown-6)CN. Similarly reaction of the alkali metal amides, M[N(SiR 3 )R'] (M = Li, K; R = Ph, Me; R' = alkyl, aryl) provides the corresponding 13 C labeled isocyanide RN 13 C and MOSiR 3 , generally in high yields. In some instances, the use of the sterically bulky Ph 3 Si-substituent is required to preclude 1,2-silyl migration affording the silylcarbamoyl salt M[Me 3 SiC(O)NR']. These reactions have been used to obtain 19 examples of 13 C labelled isocyanides, and several examples of gram scale reactions are reported. The mechanism of the reactions is probed via reliable DFT calculations.