Catalytic Enantioselective Pudovik Reaction of Aldehydes and Aldimines with Tethered Bis(8-quinolinato) (TBOx) Aluminum Complex
摘要:
New chiral tethered bis(8-quinolinolato) (TBOx) aluminum(III) complexes effectively catalyze the addition of phosphites to aldehydes and aldimines to give enantioenriched alpha-hydroxy and a-amino phosphonates in high yields and enantioselectivities with unprecedented reactivity (TON = 100 as high as 200). The catalyst is optimized with the low catalyst loading of 0.5 - 1.0 mol %. The modular synthesis of the catalyst allows for potential to tune the reaction for maximum catalytic activity. To date there are few examples with broad substrate scopes that can catalyze both aldehydes and aldimines with such high selectivity and no reports utilizing such low catalyst loading.
Catalytic Enantioselective Pudovik Reaction of Aldehydes and Aldimines with Tethered Bis(8-quinolinato) (TBOx) Aluminum Complex
摘要:
New chiral tethered bis(8-quinolinolato) (TBOx) aluminum(III) complexes effectively catalyze the addition of phosphites to aldehydes and aldimines to give enantioenriched alpha-hydroxy and a-amino phosphonates in high yields and enantioselectivities with unprecedented reactivity (TON = 100 as high as 200). The catalyst is optimized with the low catalyst loading of 0.5 - 1.0 mol %. The modular synthesis of the catalyst allows for potential to tune the reaction for maximum catalytic activity. To date there are few examples with broad substrate scopes that can catalyze both aldehydes and aldimines with such high selectivity and no reports utilizing such low catalyst loading.
Catalytic Enantioselective Hydrophosphonylation of Aldehydes Using the Iron Complex of a Camphor-Based Tridentate Schiff Base [FeCl(SBAIB-d)]<sub>2</sub>
作者:Ramalingam Boobalan、Chinpiao Chen
DOI:10.1002/adsc.201300653
日期:2013.11.25
AbstractAn 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%).magnified image