Synthesis and Structural Characterization of New Hindered Aryl Phosphorus Centers (Aryl = 2,6-Dimesitylphenyl)
TL;DR: The sterically encumbered dichlorophosphine ArPCl2 (Ar = 2,6-dimesitylphenyl = Dmp,1) has been prepared from the corresponding aryliodide, n-butyllithium, and phosphorus trichloride as discussed by the authors.
Abstract: The new sterically encumbered dichlorophosphine ArPCl2 (Ar = 2,6-dimesitylphenyl = Dmp,1) has been prepared from the corresponding aryliodide, n-butyllithium, and phosphorus trichloride. DmpPCl2 served as a precursor for the phosphinic acid DmpP(O)(OH)H(2), primary phosphine DmpPH2 (3), and diphosphene DmpP = PDmp (4). Compounds 2 and 4 have been crystallographically characterized. The solid state structure of 2 reveals the existence of dimeric phosphinic acids associated by hydrogen bonding in a manner analogous to carboxylic acid dimers. The P‒O distances are 1.508(2) and 1.521(2) A, and the O‒H and O‒H…O distances are 1.06(4) and 1.46(4), consistent with localized hydrogen bonding. The structure of 4 features a trans configuration about the P = P bond and short P = P bond length of 1.985 (2) A. Crystal data for compound 2: a = 9.4552(8) A, b = 11.174(1) A, c = 11.711(1) A, α = 65.775(8) A, β = 75.735(7)°, γ = 69.621(7)°, triclinic, P—1,Z = 2. Crystal data for compound 4: a = 10.940(1) A, b = 22.323(2) ...
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TL;DR: The key unifying feature of almost all molecules discussed in this review is that they are generally stabilized by the use of bulky substituents which block associative or various decomposition pathways.
Abstract: This review is essentially an update of one entitled “πBonding and The Lone Pair Effect in Multiple Bonds Between Heavier Main Group Elements” which was published more than 10 years ago in this journal.1 The coverage of that survey was focused on the synthesis, structure, and bonding of stable compounds2 of heavier main group elements that correspond to the skeletal drawings reproduced in Tables 1 and 2. A row of numbers is listed at the bottom of each column in these tables. This refers to the number of stable complexes from each class that are currently known. The numbers in parentheses refer to the number of stable species that were known at the time of the previous review. Clearly, many of the compound classes listed have undergone considerable expansion although some remain stubbornly rare. The most significant developments for each class will be discussed in detail under the respective sections. As will be seen, there are also a limited number of multiple bonded heavier main group species that do not fit neatly in the classifications in Tables 1 and 2. However, to keep the review to a manageable length, the limits and exclusions, which parallel those used earlier, are summarized as follows: (i) discussion is mainly confined to compounds where experimental data on stable, isolated species have been obtained, (ii) stable compounds having multiple bonding between heavier main group elements and transition metals are not generally discussed, (iii) compounds in which a multiple bonded heavier main group element is incorporated within a ring are generally not covered, and (iv) hypervalent main group compounds that may incorporate faux multiple bonding are generally excluded. Such compounds are distinguished from those in Tables 1 and 2 in that they apparently require the use of more than four valence bonding orbitals at one or more of the bonded atoms. The remainder of this review is organized in a similar manner to that of the previous one wherein the compounds to be discussed are classified according to those summarized in Tables 1 and 2. The key unifying feature of almost all molecules discussed in this review is that they are generally stabilized by the use of bulky substituents which block associative or various decomposition pathways.3 Since the previous review was published in 1999, several review articles that cover parts of the subject matter have appeared.4
865 citations
TL;DR: In this article, the synthesis and characterization of several m-terphenyl heavier main group 15 (P, As, Sb, or Bi) dihalides, together with their reduction to give a homologous series of double-bonded dipnictenes, are reported.
Abstract: The synthesis and characterization of several m-terphenyl heavier main group 15 (P, As, Sb, or Bi) dihalides, together with their reduction to give a homologous series of double-bonded dipnictenes, are reported. Reaction of LiC6H3-2,6-Mes2 (Mes = C6H2-2,4,6-Me3) or LiC6H3-2,6-Trip2 (Trip = C6H2-2,4,6-iPr3) with the appropriate trihalide affords 2,6-Mes2H3C6ECl2 (E = As, 1; Sb, 2; Bi, 3) and 2,6-Trip2H3C6ECl2 (E = P, 4; As, 5; Sb, 6; Bi, 7). The compounds 1−7 were characterized by 1H and 13C NMR spectroscopy as well as by 31P NMR spectroscopy in the case of 4. In addition, the structures of 3, 5, and 6 were determined. Reduction of the phosphorus species 4 with potassium in hexane gives a mixture of the diphosphene 2,6-Trip2H3C6PPC6H3-2,6-Trip2, 12, and the phosphafluorene species, 1-(2,4,6-triisopropylphenyl)-5,7-diisopropyl-9-phosphafluorene, 11. The compound 11, which results from the insertion of a phosphorus into a C(Ar)−C(i-Pr) bond was synthesized in higher yield by the reduction of 4 with magnesium...
251 citations
TL;DR: The use of the m-terphenyl substituent has facilitated the synthesis of numerous unusual molecules containing main group elements as discussed by the authors, as well as highlighting potential synthetically useful derivatives.
140 citations
TL;DR: In this paper, the major developments in the phospha-Wittig reaction are highlighted and divided into these three methodologies, and the complementary nature and the differences between the three approaches are also discussed.
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TL;DR: Synthese de m-terphenyle, diaryl-, dimethoxy-, tetramethoxy-mterphenyles, de mquinquephenyle and de mphenylene bis-naphtalenes par reaction de trihalogeno benzenes avec des bromures d'aryl-magnesium as discussed by the authors.
Abstract: Synthese de m-terphenyle, diaryl-, dimethoxy-, tetramethoxy-m-terphenyles, de m-quinquephenyle et de m-phenylene bis-naphtalenes par reaction de trihalogeno benzenes avec des bromures d'aryl-magnesium
201 citations