Synthesis of acyl(chloro)phosphines enabled by phosphinidene transfer

Abstract

Acyl(chloro)phosphines RC(O)P(Cl)(t-Bu) have been prepared by formal insertion of tert-butyl phosphinidene (t-Bu–P) from t-BuPA (A = C14H10 or anthracene) into the C–Cl bond of acyl chlorides.

Diphospha‐Ureas from the Phosphaketene Ph3GePCO

“…The P−C distances were determined to be 1.901(3) and 1.779(3) Å, whereas the P‐C‐P angle and the C−O distance were 110.32(3)° and 1.246(3) Å, respectively. These metric parameters also reflect the delocalization of the negative charge across the P‐C‐O moiety, similar to that seen in the anions [Ph 3 BOC(H)PGePh 3 )] − and [PhC(O)P t Bu] − . The salt [K(18c6)][ 1 ] proved to be stable at ambient temperatures.…”

“…The PÀCd istances were determined to be 1.901(3) and 1.779 (3) ,w hereas the P-C-P angle and the CÀOd istance were 110.32(3)8 and 1.246(3) ,r espectively.T hese metric parameters also reflect the delocalization of the negative charge across the P-C-O moiety,s imilar to that seen in the anions [Ph 3 BOC(H)PGePh 3 )] À and [PhC(O)PtBu] À . [6,12] [13] The electronic nature of the anion wasp robedu sing density-functional methods with the B3LYP functional and the def2-TZVP basis set (with Grimme's GD3BJ dispersion correction), using the model compound [Me 2 PC(O)PMe] À ([1-Me]; see the Supporting Information for full details). [14] The E isomer of w as found to be thermodynamically favored by 5.1 kcal mol À1 relative to the Z isomer.N atural resonance theory (NRT) analysiss hows two dominant resonance structures for , highlighting the delocalization of the negative chargeo ver the P-C-O fragment, consistentw itht he similarW iberg bond indices of the CÀOa nd CÀPb onds of 1.50 and 1.43, respectively.…”

Acylation Reactions of Dibenzo‐7‐phosphanorbornadiene: DFT Mechanistic Insights

“…Acylphosphines and their oxides are useful photo‐initiators for radical polymerization reactions, usually synthesized by using nucleophilic sources of phosphorus such as PH 3 , MPH 2 (M=Li, Na, K), P(TMS) 3 (TMS=trimethylsilyl), and transition metal‐supported phosphines and phosphides . Very recently, novel acylation reactions of tert ‐butyl dibenzo‐7‐phosphanobornadiene ( R or RP A , A =anthracene C 14 H 10 ) with both benzoyl chloride (PhCOCl) and benzoyl triflate (PhCOOTf, OTf=OSO 2 CF 3 ) in dichloromethane CH 2 Cl 2 solution were reported (Scheme ), leading to neutral acyl(chloro)phosphine B (together with anthracene C 14 H 10 ) and acylphosphonium A + (together with a triflate anion OTf − ), respectively. The cation A + is stable in the solid state at low temperature but does rearrange or decompose slowly at ambient temperature, putatively leading to an anthracenyl (acyl)hydridophosphnium F + that can be further deprotonated by the base triethylamine Et 3 N .…”

“…Very recently, novel acylation reactions of tert ‐butyl dibenzo‐7‐phosphanobornadiene ( R or RP A , A =anthracene C 14 H 10 ) with both benzoyl chloride (PhCOCl) and benzoyl triflate (PhCOOTf, OTf=OSO 2 CF 3 ) in dichloromethane CH 2 Cl 2 solution were reported (Scheme ), leading to neutral acyl(chloro)phosphine B (together with anthracene C 14 H 10 ) and acylphosphonium A + (together with a triflate anion OTf − ), respectively. The cation A + is stable in the solid state at low temperature but does rearrange or decompose slowly at ambient temperature, putatively leading to an anthracenyl (acyl)hydridophosphnium F + that can be further deprotonated by the base triethylamine Et 3 N . Gas‐phase DFT calculations supported the ion‐pair A + Cl − but precluded the phosphenium E + as potential intermediates in the reaction with PhCOCl .…”

“…The cation A + is stable in the solid state at low temperature but does rearrange or decompose slowly at ambient temperature, putatively leading to an anthracenyl (acyl)hydridophosphnium F + that can be further deprotonated by the base triethylamine Et 3 N . Gas‐phase DFT calculations supported the ion‐pair A + Cl − but precluded the phosphenium E + as potential intermediates in the reaction with PhCOCl . As will be shown below, inclusion of solvation effects in the theoretical treatment for ionic species is essential to provide reliable energetics for such reactions in solution.…”