Ortho‐Trialkylstannyl Arylphosphanes by C–P and C–Sn Bond Formation in Arynes

Abstract

A novel and efficient approach to ortho-trialkylstannyl arylphosphanes by the reaction of arynes generated in situ with stannylated phosphanes (R3Sn-PR2) is described. Concurrent C-P and C-Sn bond formation occurs with high yields, and stannylated products are easily transformed into valuable ortho-substituted arylphosphanes. The reaction features high efficiency, good regioselectivity, and excellent practicality.

Reactions of Organophosphorus Compounds with Arynes: Reactivity and Mechanism

“…In 2016, Studer group reported the insertion reaction of arynes to stannylated phosphanes, providing various o ‐trialkylstannyl arylphosphanes in moderate to good yields (Scheme 11). [23] In this paper, commonly‐used Kobayashi aryne precursors failed to give target products as fluorides could trigger the decomposition of stannylated phosphanes. Instead, 2‐iodophenyl 4‐chlorobenzenesulfonates were utilized to afford aryne species upon treatment with i ‐PrMgCl⋅LiCl at −78 °C.…”

Synthesis of Stannylated Aryl Imines and Amines via Aryne Insertion Reactions into Sn−N Bonds

“…Note that the latter two processes do not rely on direct σ‐bond insertion reactions. Moreover, various methods for the construction of C−N and C−Sn bonds involving aryne intermediates are known [31–39] …”

“…Moreover, various methods for the construction of CÀ N and CÀ Sn bonds involving aryne intermediates are known. [31][32][33][34][35][36][37][38][39] Inspired by our previously reported stannylphosphanylation of aryne intermediates that uses stannylated phosphanes as reagents, [31] we herein report a practical method to implement an N-substituent to an aryl compound along with a stannyl moiety in ortho position via aryne insertion into the NÀ Sn bond of a stannylated imine (Scheme 1C). Notable features of the novel method are: a) the imine functionality installed serves as a protecting group and the free anilines are readily obtained upon simple hydrolysis; b) the simultaneously formed ortho-Snaryl bond has a large synthetic value which is documented by several follow-up reactions showing the diversity that can be achieved by using this approach.…”

Discussion Addendum for: The Direct Acyl-Alkylation of Arynes. Preparation of Methyl 2-(2-acetylphenyl)acetate

“…65,66 They have also identified arynes as latent aryl anion equivalents. 67 The Studer lab has reported the formation of ortho-sulfinylaryl vinyl ethers, 68 biphenyls, 69 trialkylstannyl arylphosphanes, 70 and sulfonium ylides 71 by means of aryne insertion chemistry. The Lautens group has actively explored the applications of the intramolecular aryne-ene reactions.…”