Use the links on the nhc home page to answer these question 使用鏈接在nhc主頁(yè)回答這些問(wèn)題。
National hurricane center , nhc 國(guó)家颶風(fēng)中心
By using sterically hindered , electron - rich alkylphosphines and n - heterocyclic carbenes ( nhc ) , this process has encompassed a broad range of substrates including ketones , aldehydes , esters , amides , malonates , nitrocompounds , nitriles and sulfones 隨著大位阻、富電子烷基膦和氮雜環(huán)卡賓( nhc )為配體的催化體系的出現(xiàn),該類反應(yīng)的底物已從酮擴(kuò)展到醛、酯、酰胺以及含酸性氫的化合物如丙二酸酯、硝基化合物、腈、砜等。