Direct Enantioselective Three‐Component Kabachnik–Fields Reaction Catalyzed by Chiral Bis(imidazoline)‐Zinc(II) Catalysts

A direct three‐component reaction of aldehydes, amines and diaryl phosphites was catalyzed by a zinc(II) complex of 1,3‐bis(imidazolin‐2‐ly)pyridine (pybim) giving the corresponding α‐aminophosphonates in good yield with good enantioselectivity. The reaction was applied to a wide variety of aromatic aldehydes to give products with excellent yields (up to 99%) and enantiomeric excesses (up to 93% ee).     

Asymmetric Hydrophosphonylation of Aldehydes using a Cinchona–Diaminomethylenemalononitrile Organocatalyst

For the asymmetric hydrophosphonylation of aldehydes, an efficient organocatalytic approach with a diaminomethylenemalononitrile‐based hydrogen‐bonding donor catalyst is presented. The catalyst induces high yields and excellent enantioselectivities (up to 98% yield, 96% ee).

     

Catalytic Enantioselective Hydrophosphonylation of Aldehydes Using the Iron Complex of a Camphor‐Based Tridentate Schiff Base [FeCl(SBAIB‐d)]2

An iron(III)‐Schiff base‐catalyzed, highly enantioselective hydrophosphonylation of various aldehydes is described. Under the optimized reaction conditions, 5 mol% of the iron/camphor‐based tridentate Schiff base complex [FeCl(SBAIB‐d)]₂ produces high yields (up to 99%) of α‐hydroxy phosphonates in excellent enantioselectivities (up to 99%). The merits of this catalytic system are an easily synthesizable catalyst, inexpensive starting materials, practically simple aerobic reaction conditions, and low catalyst loading (5 mol%).

     

Organocatalytic Enantioselective Hydrophosphonylation of Sulfonylimines having a Heteroarenesulfonyl Group as a Novel Stereocontroller

Organocatalytic enantioselective hydrophosphonylation of imines having the a heteroarenesulfonyl group afforded the respective products with high enantioselectivity. Both enantiomers of α‐amino phosphonates were obtained by using different Cinchona alkaloids with up to 98% ee.     

Catalytic Enantioselective Hydrophosphonylation of Aldehydes and Imines

In this review, recent advances in catalytic asymmetric hydrophosphonylation of aldehydes and imines are discussed. We also summarize several proposed mechanisms for the different possibilities of asymmetric induction and the application of this catalytic methodology to the enantioselective synthesis of α‐amino and α‐hydroxy phosphonates. A variety of metal‐based chiral catalysts as well as several organic catalysts have been exploited as suitable systems for the preparation of enantiomerically pure phosphonates. The recent evolution and future trends of those and other catalytic systems are described.     

SO_4~(2-)/TiO_2固体酸负载BINOL催化膦氢化反应

将SO_4~(2-)型固体酸SO_4~(2-)/TiO_2的Lewis酸性位点与BINOL的Brnsted酸性位点进行负载,制备出具有较强双氢键供体的BINOL负载的SO_4~(2-)/TiO_2催化剂。以不同取代基团的芳香族伯胺和肉桂醛缩合制备的芳香族亚胺为催化底物,在10 mol%BINOL负载的SO_4~(2-)/TiO_2催化剂的催化作用下,与亚磷酸二烷基酯(亲核试剂)进行膦氢化反应。同时,通过对比固体酸SO_4~(2-)/TiO_2、BINOL、BINOL负载的SO_4~(2-)/TiO_2催化剂的催化活性,从而对BINOL负载的SO_4~(2-)/TiO_2催化剂进行客观地评价。另外,在较优的催化条件下,以BINOL负载的SO_4~(2-)/TiO_2为催化剂,成功地合成了α-氨基膦酸酯类衍生物,且产率可达80%~88%。另外,基于氢键的作用模式,提出了适合于膦氢化反应较为合理的作用机理。     

Highly Efficient Synthesis of Quaternary α‐Hydroxy Phosphonates via Lewis Acid‐Catalyzed Hydrophosphonylation of Ketones

A Lewis acid catalyst has been first applied to the hydrophosphonylation of ketones, giving the corresponding quaternary α‐hydroxy phosphonates in high yields (up to 98%). The present method was highly tolerable for functionalized ketones. Moreover, the first catalytic enantioselective hydrophosphonylation of an unactivated ketone was also realized by using a tridentate Schiff base‐titanium complex.