Alkylphosphinites as Synthons for Stabilized Carbocations

Abstract

We present a new acid-free method for the generation of carbocations based on a redox condensation reaction that enables SN1 reactions with a variety of nucleophiles. We utilize readily synthesized phosphinites that are activated by diisopropyl azodicarboxylate to form betaine structures that collapse upon adding a pronucleophile, thereby yielding reactive carbocation intermediates. We also employ this approach for the alkylation of some bioactive molecules.

Sustainable Synthesis of Diamondoid Ethers by High-Temperature Ball Milling

“…The content of the jar was collected, and the crude reaction mixture was purified using column chromatography (SiO 2 or Al 2 O 3 ) to yield the corresponding diamondoid ether. 1 H and 13 C NMR spectra were recorded with Bruker AV-300 or AV-600 NMR spectrometers, and the chemical shifts were referenced to the residual proton or carbon signal of the used deuterated solvent. IR spectra were recorded with an FT-IR ABB Bomem MB 102 or FT-IR-ATR PerkinElmer UATR Two spectrometers (range 400−4000 cm −1 ).…”

“…While selective chemical functionalization of diamondoids has been systematically described in the literature, ,− there exist only a few examples of direct linking of two or more diamondoid cages via heteroatoms. − For instance, 1,1′-diadamantyl ether ( 1 ) was first reported as a side product in the synthesis of aryl adamantly ethers . Afterward, the preparation of 1 was reported by several other authors, but mainly as a by-product of various reactions. − Only recently was its first targeted synthesis reported. ,, We were intrigued by a possible preparation scope for the derivatives consisting of two diamondoid cages connected by an oxygen atom. We recently reported on the synthesis and spontaneous self-assembly of ethers 1 , 2 , and 4 on the highly oriented pyrolytic graphite (HOPG) surface, shedding light on the importance of London dispersion interactions for on-surface supramolecular systems of this type .…”

“…37−40 Only recently was its first targeted synthesis reported. 13,41,42 We were intrigued by a possible preparation scope for the derivatives consisting of two diamondoid cages connected by an oxygen atom. We recently reported on the synthesis and spontaneous self-assembly of ethers 1, 2, and 4 on the highly oriented pyrolytic graphite (HOPG) surface, shedding light on the importance of London dispersion interactions for on-surface supramolecular systems of this type.…”

Branching out: redox strategies towards the synthesis of acyclic α-tertiary ethers

“…A betaine intermediate was proposed to form, from reaction between the phosphinite and DIAD, which was capable of deprotonation of a pro-nucleophile. 319…”

All That metas─Synthesis of Dispersion Energy Donor-Substituted Benzenes

“…The yields are comparable in all cases and vary between 66 and 76% over two steps (Scheme 2). Diamondoid-substituted catechols were obtained via alkylation of 1,2-dihydroxybenzene by activation of diamondoid phosphinites 23 to yield mainly the 3,5-isomers 4j and 4k, with small amounts of the 3,6-substituted isomers 4ja and 4ka (for detailed procedures, see the Supporting Information).…”