Synthesis of proazaphosphatranes and their applications in organic synthesis

This study was aimed at finding useful applications for proazaphosphatranes in organic synthesis. We also sought more practical syntheses for this class of compounds. These objectives have been met and the syntheses of three new proazaphosphatranes are also reported;This dissertation is divided into ten chapters. Only chapters 1, 3 and 10 are not manuscripts of papers either published or in the process of being submitted for publication. The first chapter outlines background information on proazaphosphatranes. In the second chapter, the syntheses of the three new proazaphosphatranes P(Me2CHCH2NCH2CH 2)3N, P(Me3CCH2NCH2CH 2)3N, and P(Me2CHNCH2CH2)(HNCH 2CH2)2N are reported. The first two bases are strong and highly stable to oligomerization while the last is highly unstable in this regard and can be studied only in solution or within 24 h of its preparation. The third chapter deals with the modification of the synthesis of the intermediates leading to the highly basic and stable proazaphosphatrane P(MeLCHNCH 2CHL)3N. Although this chapter is not a paper, it is in the process of being submitted to Iowa State Research Foundation (ISURF) as a Record of Invention;The six chapters that follow are dedicated to the applications of the proazaphosphatranes in organic synthesis. Thus, in the fourth chapter, the use of proazaphosphatranes in the preparation of glutaronitriles from aldehydes and acetonitrile or from methylene-interrupted (beta,gamma-unsaturated nitriles in benzene is covered. In the fifth chapter, the use of proazaphosphatranes in the synthesis of beta-hydroxy nitriles in the presence of MgSO4 is reported. The preparation of (beta-nitroalkanols is described in Chapter 6. In Chapter 7, proazaphosphatranes are used to promote Wittig-like reactions and also the synthesis of coumarins. Chapter 8 covers the use of proazaphosphatranes in Michael addition reactions of alcohols, nitroalkanes and imines derived from (alpha-amino esters. In Chapter 9, the synthesis of oxazolidines with excellent anti-selectivity is disclosed. The final chapter contains a brief conclusion that outlines the objectives of the project that have been met

Deprotonation of Benzylic Ethers Using a Hindered Phosphazene Base. A Synthesis of Benzofurans from Ortho-Substituted Benzaldehydes

The hindered nonionic phosphazene base P4-t-Bu efficiently deprotonates o-arylmethoxy benzaldehydes, leading to a direct synthesis of benzofurans. Strong ionic bases such as LDA, LiTMP, and KH failed

Synthesis of proazaphosphatranes and their applications in organic synthesis

This study was aimed at finding useful applications for proazaphosphatranes in organic synthesis. We also sought more practical syntheses for this class of compounds. These objectives have been met and the syntheses of three new proazaphosphatranes are also reported;This dissertation is divided into ten chapters. Only chapters 1, 3 and 10 are not manuscripts of papers either published or in the process of being submitted for publication. The first chapter outlines background information on proazaphosphatranes. In the second chapter, the syntheses of the three new proazaphosphatranes P(Me2CHCH2NCH2CH 2)3N, P(Me3CCH2NCH2CH 2)3N, and P(Me2CHNCH2CH2)(HNCH 2CH2)2N are reported. The first two bases are strong and highly stable to oligomerization while the last is highly unstable in this regard and can be studied only in solution or within 24 h of its preparation. The third chapter deals with the modification of the synthesis of the intermediates leading to the highly basic and stable proazaphosphatrane P(MeLCHNCH 2CHL)3N. Although this chapter is not a paper, it is in the process of being submitted to Iowa State Research Foundation (ISURF) as a Record of Invention;The six chapters that follow are dedicated to the applications of the proazaphosphatranes in organic synthesis. Thus, in the fourth chapter, the use of proazaphosphatranes in the preparation of glutaronitriles from aldehydes and acetonitrile or from methylene-interrupted (beta,gamma-unsaturated nitriles in benzene is covered. In the fifth chapter, the use of proazaphosphatranes in the synthesis of beta-hydroxy nitriles in the presence of MgSO4 is reported. The preparation of (beta-nitroalkanols is described in Chapter 6. In Chapter 7, proazaphosphatranes are used to promote Wittig-like reactions and also the synthesis of coumarins. Chapter 8 covers the use of proazaphosphatranes in Michael addition reactions of alcohols, nitroalkanes and imines derived from (alpha-amino esters. In Chapter 9, the synthesis of oxazolidines with excellent anti-selectivity is disclosed. The final chapter contains a brief conclusion that outlines the objectives of the project that have been met.</p