P(i-PrNCH2CH2)3N: an efficient catalyst for TMS-1,3-dithiane addition to aldehydes

Bu4N+ Alkoxide-Initiated/Autocatalytic Addition Reactions with Organotrimethylsilanes

“…4a This reaction was chosen to develop a new non-fluoride activation method with an initial screen of the three different Lewis bases tBuOK, EtOK and Me 3 SiOK carried out. Alkoxides were chosen to encompass their alcohol pKa range of 17,16 and 12.7 respectively. 7 Using the identical conditions but replacing fluoride with an alkoxide failed to produce 14a even after prolonged reaction times (entries 2-4).…”

Emergence of Hemicryptophanes: From Synthesis to Applications for Recognition, Molecular Machines, and Supramolecular Catalysis

“…Proazaphosphatranes, also known as Verkade’s superbases, and their azaphosphatrane protonated counterparts exhibit catalytic properties in a wide range of reactions. ,− In 2011, Dutasta and Martinez et al synthesized the first hemicryptophane-Verkade’s superbase P@ 15a and its conjugated acid PH + @ 15a from their precursor 15a using the experimental conditions reported for other azaphosphatranes (Scheme ). Addition of hemicryptophane 15a to a solution of [(CH 3 ) 2 N] 2 PCl in CH 3 CN afforded PH + @ 15a in 35% yield, which was then deprotonated using potassium tert -butoxide ( t -BuOK) in THF to give the encaged superbase P@ 15a in 80% yield. , The azaphosphatrane-hemicryptophanes PH + @ 15a was optically resolved by chiral semipreparative HPLC, leading to the enantiopure compounds PH + @ M - 15a and PH + @ P - 15a .…”

“…Pro-azaphosphatranes, often named Verkade’s superbases (p K a ≈ 32), display remarkable properties as basic or nucleophilic catalysts in numerous reactions, such as transesterification, allylation, silylation, and elimination. ,, In contrast, their conjugated acid azaphosphatranes, resulting from protonation of the phosphorus atom of the proazaphosphatrane, have received less attention. In this section, the use of encaged azaphosphatrane and Verkade’s superbase hemicryptophane complexes as organocatalysts is described.…”

Interactions of Verkade’s Superbase with Strong Lewis Acids: From Labile Mono- and Binuclear Lewis Acid–Base Complexes to Phosphenium Cations

“…Proazaphosphatranes, also referred to as Verkade’s bases, are exceptionally strong nonionic Brønsted bases of the general formula N­[CH 2 CH 2 N­(R)] 3 P, where R = H, Me, Bu i , Pr i , Bn, etc. − Pioneering work by the Verkade group has demonstrated these cagelike compounds to be valuable alternatives to inorganic bases in numerous base-catalyzed C–C, C–O, and C–N bond-forming reactions. − Proazaphosphatranes have also been reported to be superior in selectively deprotonating the cationic species L 2 RhH 2 + and L 2 CoH 2 + to generate L 2 RhH and L 2 CoH, highly active and robust catalysts in the hydrogenation of CO 2 . , Sneddon’s group and others have discovered that by the selective deprotonation of H 3 NBH 3 , a potentially useful hydrogen storage material, with Verkade’s base, structurally well-defined anionic borane-capped ammonia borane oligomers could be synthesized. , …”